fix: migrate legacy repository references

Merge remote-tracking branch 'refs/remotes/origin/hare/develop' into develop
fix: preserve blocked TUI submissions
2026-09-03 11:09:55 +09:00 · 2026-09-03 09:47:53 +09:00 · 2026-09-03 08:57:28 +09:00 · 2026-09-03 08:44:28 +09:00 · 2026-09-03 08:38:15 +09:00 · 2026-09-03 08:21:11 +09:00
390 changed files with 64459 additions and 29964 deletions
@@ -0,0 +1,3 @@
+[build]
+build-dir = "{cargo-cache-home}/build/{workspace-path-hash}"
+incremental = false
@@ -26,6 +26,16 @@ dependencies = [
 "pom",
 ]

+[[package]]
+name = "aead"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
+dependencies = [
+ "crypto-common 0.1.7",
+ "generic-array",
+]
+
 [[package]]
 name = "aes"
 version = "0.8.4"
@@ -37,6 +47,20 @@ dependencies = [
 "cpufeatures 0.2.17",
 ]

+[[package]]
+name = "aes-gcm"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "831010a0f742e1209b3bcea8fab6a8e149051ba6099432c8cb2cc117dec3ead1"
+dependencies = [
+ "aead",
+ "aes",
+ "cipher",
+ "ctr",
+ "ghash",
+ "subtle",
+]
+
 [[package]]
 name = "agen"
 version = "0.2.1"
@@ -326,6 +350,12 @@ dependencies = [
 "tracing",
 ]

+[[package]]
+name = "base16ct"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"
+
 [[package]]
 name = "base64"
 version = "0.21.7"
@@ -338,6 +368,12 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"

+[[package]]
+name = "base64ct"
+version = "1.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2af50177e190e07a26ab74f8b1efbfe2ef87da2116221318cb1c2e82baf7de06"
+
 [[package]]
 name = "base64urlsafedata"
 version = "0.5.5"
@@ -349,6 +385,17 @@ dependencies = [
 "serde",
 ]

+[[package]]
+name = "bcrypt-pbkdf"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6aeac2e1fe888769f34f05ac343bbef98b14d1ffb292ab69d4608b3abc86f2a2"
+dependencies = [
+ "blowfish",
+ "pbkdf2",
+ "sha2 0.10.9",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.5.3"
@@ -403,6 +450,16 @@ dependencies = [
 "generic-array",
 ]

+[[package]]
+name = "blowfish"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e412e2cd0f2b2d93e02543ceae7917b3c70331573df19ee046bcbc35e45e87d7"
+dependencies = [
+ "byteorder",
+ "cipher",
+]
+
 [[package]]
 name = "bstr"
 version = "1.12.1"
@@ -435,6 +492,12 @@ version = "1.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8efb64bd706a16a1bdde310ae86b351e4d21550d98d056f22f8a7f7a2183fec"

+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
 [[package]]
 name = "bytes"
 version = "1.11.1"
@@ -495,6 +558,17 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"

+[[package]]
+name = "chacha20"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3613f74bd2eac03dad61bd53dbe620703d4371614fe0bc3b9f04dd36fe4e818"
+dependencies = [
+ "cfg-if",
+ "cipher",
+ "cpufeatures 0.2.17",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.44"
@@ -563,8 +637,9 @@ checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 name = "client"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
+ "chrono",
 "futures",
- "manifest",
 "protocol",
 "reqwest",
 "serde",
@@ -575,7 +650,6 @@ dependencies = [
 "tokio",
 "tokio-tungstenite 0.29.0",
 "uuid",
- "workdir",
 "workspace-api",
 ]

@@ -654,6 +728,12 @@ dependencies = [
 "wasm-bindgen",
 ]

+[[package]]
+name = "const-oid"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
+
 [[package]]
 name = "const-oid"
 version = "0.10.2"
@@ -937,6 +1017,18 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "460fbee9c2c2f33933d720630a6a0bac33ba7053db5344fac858d4b8952d77d5"

+[[package]]
+name = "crypto-bigint"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0dc92fb57ca44df6db8059111ab3af99a63d5d0f8375d9972e319a379c6bab76"
+dependencies = [
+ "generic-array",
+ "rand_core 0.6.4",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "crypto-common"
 version = "0.1.7"
@@ -966,6 +1058,41 @@ dependencies = [
 "phf 0.11.3",
 ]

+[[package]]
+name = "ctr"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0369ee1ad671834580515889b80f2ea915f23b8be8d0daa4bbaf2ac5c7590835"
+dependencies = [
+ "cipher",
+]
+
+[[package]]
+name = "curve25519-dalek"
+version = "4.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97fb8b7c4503de7d6ae7b42ab72a5a59857b4c937ec27a3d4539dba95b5ab2be"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.2.17",
+ "curve25519-dalek-derive",
+ "digest 0.10.7",
+ "fiat-crypto",
+ "rustc_version",
+ "subtle",
+]
+
+[[package]]
+name = "curve25519-dalek-derive"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f46882e17999c6cc590af592290432be3bce0428cb0d5f8b6715e4dc7b383eb3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "darling"
 version = "0.23.0"
@@ -1056,6 +1183,16 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5729f5117e208430e437df2f4843f5e5952997175992d1414f94c57d61e270b4"

+[[package]]
+name = "der"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
+dependencies = [
+ "const-oid 0.9.6",
+ "zeroize",
+]
+
 [[package]]
 name = "der-parser"
 version = "9.0.0"
@@ -1114,7 +1251,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
 "block-buffer 0.10.4",
+ "const-oid 0.9.6",
 "crypto-common 0.1.7",
+ "subtle",
 ]

 [[package]]
@@ -1124,7 +1263,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4850db49bf08e663084f7fb5c87d202ef91a3907271aff24a94eb97ff039153c"
 dependencies = [
 "block-buffer 0.12.0",
- "const-oid",
+ "const-oid 0.10.2",
 "crypto-common 0.2.1",
 ]

@@ -1175,12 +1314,66 @@ dependencies = [
 "cipher",
 ]

+[[package]]
+name = "ecdsa"
+version = "0.16.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
+dependencies = [
+ "der",
+ "digest 0.10.7",
+ "elliptic-curve",
+ "rfc6979",
+ "signature",
+ "spki",
+]
+
+[[package]]
+name = "ed25519"
+version = "2.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "115531babc129696a58c64a4fef0a8bf9e9698629fb97e9e40767d235cfbcd53"
+dependencies = [
+ "signature",
+]
+
+[[package]]
+name = "ed25519-dalek"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70e796c081cee67dc755e1a36a0a172b897fab85fc3f6bc48307991f64e4eca9"
+dependencies = [
+ "curve25519-dalek",
+ "ed25519",
+ "sha2 0.10.9",
+ "subtle",
+]
+
 [[package]]
 name = "either"
 version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"

+[[package]]
+name = "elliptic-curve"
+version = "0.13.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5e6043086bf7973472e0c7dff2142ea0b680d30e18d9cc40f267efbf222bd47"
+dependencies = [
+ "base16ct",
+ "crypto-bigint",
+ "digest 0.10.7",
+ "ff",
+ "generic-array",
+ "group",
+ "pkcs8",
+ "rand_core 0.6.4",
+ "sec1",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "embedded-io"
 version = "0.4.0"
@@ -1284,6 +1477,22 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"

+[[package]]
+name = "ff"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0b50bfb653653f9ca9095b427bed08ab8d75a137839d9ad64eb11810d5b6393"
+dependencies = [
+ "rand_core 0.6.4",
+ "subtle",
+]
+
+[[package]]
+name = "fiat-crypto"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28dea519a9695b9977216879a3ebfddf92f1c08c05d984f8996aecd6ecdc811d"
+
 [[package]]
 name = "filedescriptor"
 version = "0.8.3"
@@ -1526,6 +1735,7 @@ checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
 dependencies = [
 "typenum",
 "version_check",
+ "zeroize",
 ]

 [[package]]
@@ -1568,6 +1778,16 @@ dependencies = [
 "wasip3",
 ]

+[[package]]
+name = "ghash"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0d8a4362ccb29cb0b265253fb0a2728f592895ee6854fd9bc13f2ffda266ff1"
+dependencies = [
+ "opaque-debug",
+ "polyval",
+]
+
 [[package]]
 name = "gimli"
 version = "0.33.0"
@@ -1636,6 +1856,17 @@ dependencies = [
 "memmap2",
 ]

+[[package]]
+name = "group"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0f9ef7462f7c099f518d754361858f86d8a07af53ba9af0fe635bbccb151a63"
+dependencies = [
+ "ff",
+ "rand_core 0.6.4",
+ "subtle",
+]
+
 [[package]]
 name = "h2"
 version = "0.4.13"
@@ -1724,6 +1955,15 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"

+[[package]]
+name = "hmac"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
+dependencies = [
+ "digest 0.10.7",
+]
+
 [[package]]
 name = "html5ever"
 version = "0.26.0"
@@ -2212,6 +2452,9 @@ name = "lazy_static"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+dependencies = [
+ "spin",
+]

 [[package]]
 name = "leb128fmt"
@@ -2386,6 +2629,7 @@ version = "0.1.0"
 dependencies = [
 "agen",
 "arc-swap",
+ "decodal",
 "protocol",
 "secrets",
 "serde",
@@ -2672,6 +2916,22 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "num-bigint-dig"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e661dda6640fad38e827a6d4a310ff4763082116fe217f279885c97f511bb0b7"
+dependencies = [
+ "lazy_static",
+ "libm",
+ "num-integer",
+ "num-iter",
+ "num-traits",
+ "rand 0.8.5",
+ "smallvec",
+ "zeroize",
+]
+
 [[package]]
 name = "num-conv"
 version = "0.2.1"
@@ -2698,6 +2958,16 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "num-iter"
+version = "0.1.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c92800bd69a1eac91786bcfe9da64a897eb72911b8dc3095decbd07429e8048b"
+dependencies = [
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -2705,6 +2975,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
 dependencies = [
 "autocfg",
+ "libm",
 ]

 [[package]]
@@ -2765,6 +3036,12 @@ version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"

+[[package]]
+name = "opaque-debug"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
+
 [[package]]
 name = "openssl"
 version = "0.10.76"
@@ -2818,6 +3095,44 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "p256"
+version = "0.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9863ad85fa8f4460f9c48cb909d38a0d689dba1f6f6988a5e3e0d31071bcd4b"
+dependencies = [
+ "ecdsa",
+ "elliptic-curve",
+ "primeorder",
+ "sha2 0.10.9",
+]
+
+[[package]]
+name = "p384"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe42f1670a52a47d448f14b6a5c61dd78fce51856e68edaa38f7ae3a46b8d6b6"
+dependencies = [
+ "ecdsa",
+ "elliptic-curve",
+ "primeorder",
+ "sha2 0.10.9",
+]
+
+[[package]]
+name = "p521"
+version = "0.13.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fc9e2161f1f215afdfce23677034ae137bbd45016a880c2eb3ba8eb95f085b2"
+dependencies = [
+ "base16ct",
+ "ecdsa",
+ "elliptic-curve",
+ "primeorder",
+ "rand_core 0.6.4",
+ "sha2 0.10.9",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.5"
@@ -2847,6 +3162,15 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "35fb2e5f958ec131621fdd531e9fc186ed768cbe395337403ae56c17a74c68ec"

+[[package]]
+name = "pbkdf2"
+version = "0.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8ed6a7761f76e3b9f92dfb0a60a6a6477c61024b775147ff0973a02653abaf2"
+dependencies = [
+ "digest 0.10.7",
+]
+
 [[package]]
 name = "pdf-extract"
 version = "0.10.0"
@@ -2864,6 +3188,15 @@ dependencies = [
 "unicode-normalization",
 ]

+[[package]]
+name = "pem-rfc7468"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88b39c9bfcfc231068454382784bb460aae594343fb030d46e9f50a645418412"
+dependencies = [
+ "base64ct",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -3009,6 +3342,27 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"

+[[package]]
+name = "pkcs1"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8ffb9f10fa047879315e6625af03c164b16962a5368d724ed16323b68ace47f"
+dependencies = [
+ "der",
+ "pkcs8",
+ "spki",
+]
+
+[[package]]
+name = "pkcs8"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
+dependencies = [
+ "der",
+ "spki",
+]
+
 [[package]]
 name = "pkg-config"
 version = "0.3.32"
@@ -3021,6 +3375,29 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4596b6d070b27117e987119b4dac604f3c58cfb0b191112e24771b2faeac1a6"

+[[package]]
+name = "poly1305"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8159bd90725d2df49889a078b54f4f79e87f1f8a8444194cdca81d38f5393abf"
+dependencies = [
+ "cpufeatures 0.2.17",
+ "opaque-debug",
+ "universal-hash",
+]
+
+[[package]]
+name = "polyval"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d1fe60d06143b2430aa532c94cfe9e29783047f06c0d7fd359a9a51b729fa25"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.2.17",
+ "opaque-debug",
+ "universal-hash",
+]
+
 [[package]]
 name = "pom"
 version = "1.1.0"
@@ -3101,6 +3478,15 @@ dependencies = [
 "syn 2.0.117",
 ]

+[[package]]
+name = "primeorder"
+version = "0.13.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "353e1ca18966c16d9deb1c69278edbc5f194139612772bd9537af60ac231e1e6"
+dependencies = [
+ "elliptic-curve",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.106"
@@ -3121,6 +3507,7 @@ dependencies = [
 "schemars",
 "serde",
 "serde_json",
+ "sha2 0.11.0",
 "tokio",
 "ts-rs",
 "uuid",
@@ -3525,6 +3912,16 @@ dependencies = [
 "web-sys",
 ]

+[[package]]
+name = "rfc6979"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8dd2a808d456c4a54e300a23e9f5a67e122c3024119acbfd73e3bf664491cb2"
+dependencies = [
+ "hmac",
+ "subtle",
+]
+
 [[package]]
 name = "ring"
 version = "0.17.14"
@@ -3539,6 +3936,27 @@ dependencies = [
 "windows-sys 0.52.0",
 ]

+[[package]]
+name = "rsa"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8573f03f5883dcaebdfcf4725caa1ecb9c15b2ef50c43a07b816e06799bb12d"
+dependencies = [
+ "const-oid 0.9.6",
+ "digest 0.10.7",
+ "num-bigint-dig",
+ "num-integer",
+ "num-traits",
+ "pkcs1",
+ "pkcs8",
+ "rand_core 0.6.4",
+ "sha2 0.10.9",
+ "signature",
+ "spki",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "rusqlite"
 version = "0.37.0"
@@ -3745,6 +4163,20 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"

+[[package]]
+name = "sec1"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
+dependencies = [
+ "base16ct",
+ "der",
+ "generic-array",
+ "pkcs8",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "secrets"
 version = "0.1.0"
@@ -3970,14 +4402,19 @@ dependencies = [
 "agen",
 "async-trait",
 "base64 0.22.1",
+ "fs4",
 "futures",
 "protocol",
 "serde",
 "serde_json",
+ "sha2 0.11.0",
 "tempfile",
 "thiserror 2.0.18",
 "tokio",
 "tracing",
+ "unicode-normalization",
+ "unicode-properties",
+ "unicode-security",
 "uuid",
 ]

@@ -4060,6 +4497,16 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "signature"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
+dependencies = [
+ "digest 0.10.7",
+ "rand_core 0.6.4",
+]
+
 [[package]]
 name = "simd-adler32"
 version = "0.3.9"
@@ -4103,12 +4550,99 @@ dependencies = [
 "windows-sys 0.61.2",
 ]

+[[package]]
+name = "spin"
+version = "0.9.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3763264f6b73151db08c50ff20d7d8a0b8796e021cdea7ceedad07b80155fa0e"
+
+[[package]]
+name = "spki"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
+dependencies = [
+ "base64ct",
+ "der",
+]
+
+[[package]]
+name = "ssh-cipher"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caac132742f0d33c3af65bfcde7f6aa8f62f0e991d80db99149eb9d44708784f"
+dependencies = [
+ "aes",
+ "aes-gcm",
+ "cbc",
+ "chacha20",
+ "cipher",
+ "ctr",
+ "poly1305",
+ "ssh-encoding",
+ "subtle",
+]
+
+[[package]]
+name = "ssh-encoding"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb9242b9ef4108a78e8cd1a2c98e193ef372437f8c22be363075233321dd4a15"
+dependencies = [
+ "base64ct",
+ "pem-rfc7468",
+ "sha2 0.10.9",
+]
+
+[[package]]
+name = "ssh-key"
+version = "0.6.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b86f5297f0f04d08cabaa0f6bff7cb6aec4d9c3b49d87990d63da9d9156a8c3"
+dependencies = [
+ "bcrypt-pbkdf",
+ "ed25519-dalek",
+ "p256",
+ "p384",
+ "p521",
+ "rand_core 0.6.4",
+ "rsa",
+ "sec1",
+ "sha2 0.10.9",
+ "signature",
+ "ssh-cipher",
+ "ssh-encoding",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"

+[[package]]
+name = "standalone"
+version = "0.1.0"
+dependencies = [
+ "agen",
+ "async-trait",
+ "client",
+ "fs4",
+ "futures",
+ "manifest",
+ "protocol",
+ "serde",
+ "serde_json",
+ "session-store",
+ "tempfile",
+ "thiserror 2.0.18",
+ "tokio",
+ "uuid",
+ "worker",
+]
+
 [[package]]
 name = "static_assertions"
 version = "1.1.0"
@@ -4795,10 +5329,10 @@ name = "tui"
 version = "0.1.0"
 dependencies = [
 "agen",
+ "async-trait",
 "base64 0.22.1",
 "client",
 "crossterm 0.28.1",
- "fs4",
 "manifest",
 "protocol",
 "pulldown-cmark",
@@ -4807,13 +5341,14 @@ dependencies = [
 "serde",
 "serde_json",
 "session-store",
+ "standalone",
 "tempfile",
+ "thiserror 2.0.18",
 "ticket",
 "tokio",
 "toml",
 "unicode-width",
 "uuid",
- "worker",
 ]

 [[package]]
@@ -4905,6 +5440,22 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7df058c713841ad818f1dc5d3fd88063241cc61f49f5fbea4b951e8cf5a8d71d"

+[[package]]
+name = "unicode-script"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "383ad40bb927465ec0ce7720e033cb4ca06912855fc35db31b5755d0de75b1ee"
+
+[[package]]
+name = "unicode-security"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e4ddba1535dd35ed8b61c52166b7155d7f4e4b8847cec6f48e71dc66d8b5e50"
+dependencies = [
+ "unicode-normalization",
+ "unicode-script",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.13.2"
@@ -4934,6 +5485,16 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"

+[[package]]
+name = "universal-hash"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc1de2c688dc15305988b563c3854064043356019f97a4b46276fe734c4f07ea"
+dependencies = [
+ "crypto-common 0.1.7",
+ "subtle",
+]
+
 [[package]]
 name = "unsafe-libyaml"
 version = "0.2.11"
@@ -6054,6 +6615,7 @@ dependencies = [
 "tempfile",
 "thiserror 2.0.18",
 "tokio",
+ "workspace-api",
 ]

 [[package]]
@@ -6101,6 +6663,7 @@ dependencies = [
 "wasmtime",
 "wat",
 "workdir",
+ "workspace-api",
 "yoi-plugin-pdk",
 ]

@@ -6131,9 +6694,12 @@ dependencies = [
 "tokio-tungstenite 0.29.0",
 "toml",
 "tower",
+ "url",
 "uuid",
 "workdir",
 "worker",
+ "workspace-api",
+ "zeroize",
 ]

 [[package]]
@@ -6143,7 +6709,6 @@ dependencies = [
 "serde",
 "serde_json",
 "ts-rs",
- "workdir",
 ]

 [[package]]
@@ -6257,11 +6822,13 @@ dependencies = [
 "project-record",
 "protocol",
 "reqwest",
+ "ring",
 "rusqlite",
 "serde",
 "serde_json",
 "serde_yaml",
 "sha2 0.11.0",
+ "ssh-key",
 "tempfile",
 "thiserror 2.0.18",
 "ticket",
@@ -6278,6 +6845,7 @@ dependencies = [
 "worker",
 "worker-runtime",
 "workspace-api",
+ "zeroize",
 ]

 [[package]]
@@ -5,6 +5,7 @@ members = [
    "crates/agen",
    "crates/agen-macros",
    "crates/session-store",
+    "crates/standalone",
    "crates/secrets",
    "crates/manifest",
    "crates/mcp",
@@ -36,6 +37,7 @@ default-members = [
    "crates/agen",
    "crates/agen-macros",
    "crates/session-store",
+    "crates/standalone",
    "crates/secrets",
    "crates/manifest",
    "crates/mcp",
@@ -87,6 +89,7 @@ protocol = { path = "crates/protocol" }
 session-metrics = { path = "crates/session-metrics" }
 session-analytics = { path = "crates/session-analytics" }
 session-store = { path = "crates/session-store" }
+standalone = { path = "crates/standalone" }
 secrets = { path = "crates/secrets" }
 tools = { path = "crates/tools" }
 config-source = { path = "crates/config-source" }
@@ -115,6 +118,7 @@ tar = "0.4"
 rusqlite = { version = "0.37", features = ["backup", "bundled"] }
 ring = "0.17.14"
 sha2 = "0.11"
+ssh-key = { version = "0.6.7", features = ["ed25519", "encryption"] }
 tempfile = "3.27"
 thiserror = "2.0"
 tokio = "1.52"
@@ -124,4 +128,5 @@ toml = "1.1"
 tracing = "0.1"
 url = "2.5"
 uuid = "1.23"
+zeroize = "1"
 webauthn-rs = { version = "0.5.2", features = ["danger-allow-state-serialisation", "danger-credential-internals"] }
@@ -21,7 +21,7 @@ services:
      - "8787"
    volumes:
      - server-data:/server-data
-      - ./docker/workspace:/workspace:ro
+      - /etc/yoi/server.toml:/server-config/server.toml:ro

  webui:
    image: yoi-webui:latest
@@ -21,20 +21,21 @@ agen = { version = "0.2.1", features = ["codex"] }

 ## Quick start

-Supply an implementation of [`LlmClient`](https://docs.rs/agen/latest/agen/llm_client/trait.LlmClient.html), then run a turn. The first call consumes the mutable engine and returns a cache-locked engine for later turns.
+Supply an implementation of [`LlmClient`](https://docs.rs/agen/latest/agen/llm_client/trait.LlmClient.html), keep conversation history in your application, then run a turn. The first call consumes the mutable engine and returns a cache-locked engine for later turns.

 ```no_run
-use agen::{Engine, EngineError};
+use agen::{Engine, EngineError, History};
 use agen::llm_client::LlmClient;

 async fn conversation<C: LlmClient>(client: C) -> Result<(), EngineError> {
+    let mut history = History::new();
    let output = Engine::new(client)
        .system_prompt("You are a concise assistant.")
-        .run("Explain typed state in one sentence.")
-        .await?;
+        .run(&mut history, "Explain typed state in one sentence.")
+        .await;

    let mut engine = output.engine;
-    let _result = engine.run("Give a Rust example.").await?;
+    let _result = engine.run(&mut history, "Give a Rust example.").await;
    Ok(())
 }
 ```
@@ -4,7 +4,7 @@

 use agen::llm_client::scheme::{Scheme, anthropic::AnthropicScheme};
 use agen::llm_client::transport::{HttpTransport, ResolvedAuth};
-use agen::{Engine, EngineResult};
+use agen::{Engine, EngineRunExit, StopReason};
 use std::time::Duration;

 #[tokio::main]
@@ -29,6 +29,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let base_url = scheme.default_base_url().to_string();
    let client = HttpTransport::new(scheme, model, base_url, ResolvedAuth::ApiKey(api_key), cap);
    let engine = Engine::new(client);
+    let mut history = agen::History::new();

    println!("🚀 Starting Engine...");
    println!("💡 Will cancel after 2 seconds\n");
@@ -45,16 +46,15 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {

    println!("📡 Sending request to LLM...");

-    match engine.run("Tell me a very long story about a brave knight. Make it as detailed as possible with many paragraphs.").await {
-        Ok(out) => match out.result {
-            EngineResult::Finished => println!("✅ Task completed normally"),
-            EngineResult::Paused => println!("⏸️  Task paused"),
-            EngineResult::LimitReached => println!("🔒 Turn limit reached"),
-            EngineResult::Yielded => println!("↩️  Task yielded"),
-        },
-        Err(e) => {
-            println!("❌ Task error: {}", e);
+    let output = engine.run(&mut history, "Tell me a very long story about a brave knight. Make it as detailed as possible with many paragraphs.").await;
+    match output.result {
+        EngineRunExit::Finished => println!("✅ Task completed normally"),
+        EngineRunExit::Paused => println!("⏸️  Task paused"),
+        EngineRunExit::Yielded => println!("↩️  Task yielded"),
+        EngineRunExit::Interrupted(StopReason::LimitReached) => {
+            println!("🔒 Turn limit reached")
        }
+        EngineRunExit::Interrupted(reason) => println!("❌ Task interrupted: {reason:?}"),
    }

    println!("\n✨ Demo complete!");
@@ -39,7 +39,7 @@ use tracing::info;
 use tracing_subscriber::EnvFilter;

 use agen::{
-    Engine,
+    Engine, EngineRunExit, StopReason,
    interceptor::{Interceptor, PostToolAction, ToolResultInfo},
    llm_client::{
        LlmClient,
@@ -451,6 +451,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {

    // Create Engine
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    let tool_call_names = Arc::new(Mutex::new(HashMap::new()));

@@ -476,12 +477,9 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {

    // One-shot mode
    if let Some(prompt) = args.prompt {
-        match engine.run(&prompt).await {
-            Ok(_) => {}
-            Err(e) => {
-                eprintln!("\n❌ Error: {}", e);
-                std::process::exit(1);
-            }
+        let output = engine.run(&mut history, &prompt).await;
+        if let EngineRunExit::Interrupted(StopReason::Unexpected(error)) = output.result {
+            eprintln!("\n❌ Error: {error}");
        }

        return Ok(());
@@ -500,13 +498,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        return Ok(());
    }

-    let mut locked = match engine.run(first_input).await {
-        Ok(out) => out.engine,
-        Err(e) => {
-            eprintln!("\n❌ Error: {}", e);
-            return Ok(());
-        }
-    };
+    let output = engine.run(&mut history, first_input).await;
+    let mut locked = output.engine;

    loop {
        print!("\n👤 You: ");
@@ -525,11 +518,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
            break;
        }

-        match locked.run(input).await {
-            Ok(_) => {}
-            Err(e) => {
-                eprintln!("\n❌ Error: {}", e);
-            }
+        if let EngineRunExit::Interrupted(StopReason::Unexpected(error)) =
+            locked.run(&mut history, input).await
+        {
+            eprintln!("\n❌ Error: {error}");
        }
    }

@@ -0,0 +1,199 @@
+//! Typed conversation history containers.
+//!
+//! Agen keeps provider-visible [`Item`](crate::Item) values separate from any
+//! host-domain provenance. The host chooses the annotation type `A`, while Agen
+//! preserves each item and annotation as one entry for clone/truncate/restore
+//! style history operations.
+
+use serde::{Deserialize, Serialize};
+
+use crate::Item;
+
+/// One conversation-history entry with host-owned annotation.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub struct HistoryEntry<A = ()> {
+    /// Provider/model-visible conversation item.
+    pub item: Item,
+    /// Host-domain metadata kept with the item and never projected to providers.
+    pub annotation: A,
+}
+
+impl<A> HistoryEntry<A> {
+    /// Build an entry from an item and its annotation.
+    pub fn new(item: Item, annotation: A) -> Self {
+        Self { item, annotation }
+    }
+
+    /// Split the entry into its item and annotation.
+    pub fn into_parts(self) -> (Item, A) {
+        (self.item, self.annotation)
+    }
+}
+
+impl HistoryEntry<()> {
+    /// Build a unit-annotated entry.
+    pub fn from_item(item: Item) -> Self {
+        Self {
+            item,
+            annotation: (),
+        }
+    }
+}
+
+/// Conversation history with one annotation per item.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default)]
+pub struct History<A = ()> {
+    entries: Vec<HistoryEntry<A>>,
+}
+
+impl<A> History<A> {
+    /// Create an empty history.
+    pub fn new() -> Self {
+        Self {
+            entries: Vec::new(),
+        }
+    }
+
+    /// Build history from already annotated entries, preserving order.
+    pub fn from_entries(entries: Vec<HistoryEntry<A>>) -> Self {
+        Self { entries }
+    }
+
+    /// Replace all entries as one restore/rebuild operation and return the old entries.
+    pub fn replace_entries(&mut self, entries: Vec<HistoryEntry<A>>) -> Vec<HistoryEntry<A>> {
+        std::mem::replace(&mut self.entries, entries)
+    }
+
+    /// Borrow annotated entries.
+    pub fn entries(&self) -> &[HistoryEntry<A>] {
+        &self.entries
+    }
+
+    /// Mutably borrow annotated entries for host-owned rebuild operations.
+    pub fn entries_mut(&mut self) -> &mut [HistoryEntry<A>] {
+        &mut self.entries
+    }
+
+    /// Consume the history into annotated entries.
+    pub fn into_entries(self) -> Vec<HistoryEntry<A>> {
+        self.entries
+    }
+
+    /// Number of entries.
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    /// Whether the history is empty.
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+
+    /// Iterate over annotated entries.
+    pub fn iter(&self) -> impl ExactSizeIterator<Item = &HistoryEntry<A>> {
+        self.entries.iter()
+    }
+
+    /// Iterate over provider-visible items only.
+    pub fn items(&self) -> impl ExactSizeIterator<Item = &Item> {
+        self.entries.iter().map(|entry| &entry.item)
+    }
+
+    /// Clone provider-visible items into a request-local projection.
+    pub fn items_cloned(&self) -> Vec<Item> {
+        self.items().cloned().collect()
+    }
+
+    /// Append an already annotated entry.
+    pub fn push_entry(&mut self, entry: HistoryEntry<A>) {
+        self.entries.push(entry);
+    }
+
+    /// Append many already annotated entries.
+    pub fn extend_entries(&mut self, entries: impl IntoIterator<Item = HistoryEntry<A>>) {
+        self.entries.extend(entries);
+    }
+
+    /// Commit one item through a trusted annotation callback before it becomes live.
+    ///
+    /// The callback may durably persist the item and returns the annotation that
+    /// must be stored with it. If the callback fails, the history is left unchanged.
+    pub fn append_with(
+        &mut self,
+        item: Item,
+        annotate: &mut impl FnMut(&Item) -> Result<A, String>,
+    ) -> Result<(), String> {
+        let annotation = annotate(&item)?;
+        self.entries.push(HistoryEntry { item, annotation });
+        Ok(())
+    }
+
+    /// Commit items through a trusted annotation callback before they become live.
+    ///
+    /// Items before a failure remain appended; the failing item and later items do
+    /// not enter history. This mirrors append-only durable logs where each accepted
+    /// item is already committed before the next item is attempted.
+    pub fn extend_with(
+        &mut self,
+        items: impl IntoIterator<Item = Item>,
+        annotate: &mut impl FnMut(&Item) -> Result<A, String>,
+    ) -> Result<(), String> {
+        for item in items {
+            self.append_with(item, annotate)?;
+        }
+        Ok(())
+    }
+
+    /// Truncate entries, preserving item+annotation pairing for retained entries.
+    pub fn truncate(&mut self, len: usize) {
+        self.entries.truncate(len);
+    }
+
+    /// Clear all entries.
+    pub fn clear(&mut self) {
+        self.entries.clear();
+    }
+}
+
+impl History<()> {
+    /// Build unit-annotated history from provider-visible items.
+    pub fn from_items(items: Vec<Item>) -> Self {
+        Self {
+            entries: items.into_iter().map(HistoryEntry::from_item).collect(),
+        }
+    }
+
+    /// Replace history from provider-visible items using unit annotations.
+    pub fn replace_items(&mut self, items: Vec<Item>) -> Vec<HistoryEntry<()>> {
+        self.replace_entries(items.into_iter().map(HistoryEntry::from_item).collect())
+    }
+
+    /// Append one item with unit annotation.
+    pub fn push(&mut self, item: Item) {
+        self.entries.push(HistoryEntry::from_item(item));
+    }
+
+    /// Append items with unit annotations.
+    pub fn extend_items(&mut self, items: impl IntoIterator<Item = Item>) {
+        self.entries
+            .extend(items.into_iter().map(HistoryEntry::from_item));
+    }
+}
+
+impl<A> IntoIterator for History<A> {
+    type Item = HistoryEntry<A>;
+    type IntoIter = std::vec::IntoIter<HistoryEntry<A>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.entries.into_iter()
+    }
+}
+
+impl<'a, A> IntoIterator for &'a History<A> {
+    type Item = &'a HistoryEntry<A>;
+    type IntoIter = std::slice::Iter<'a, HistoryEntry<A>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.entries.iter()
+    }
+}
@@ -2,6 +2,7 @@

 mod engine;
 mod handler;
+mod history;
 mod message;

 pub(crate) mod callback;
@@ -20,13 +21,18 @@ pub mod usage_record;
 pub use agen_macros::{description, tool, tool_registry};
 pub use callback::{TextBlockScope, ThinkingBlockScope, ToolUseBlockScope};
 pub use engine::{
-    Engine, EngineConfig, EngineError, EngineResult, EngineRunOutput, LlmRetryNotice,
-    ToolRegistryError,
+    Engine, EngineConfig, EngineError, EngineResult, EngineRunExit, EngineRunOutput,
+    LlmRetryNotice, StopReason, ToolRegistryError,
 };
 pub use handler::ToolUseBlockStart;
+pub use history::{History, HistoryEntry};
 pub use interceptor::Interceptor;
 pub use message::{ContentPart, Item, Message, Role};
-pub use tool::{ToolCall, ToolExecutionContext, ToolOutputLimits, ToolResult};
+pub use tool::{
+    ToolCall, ToolExecutionContext, ToolExecutionHandle, ToolExecutionPolicy,
+    ToolExecutionTerminal, ToolExecutionTerminalFuture, ToolOutputLimits, ToolResult,
+    ToolResultDisposition,
+};
 pub use usage_record::UsageRecord;

 /// Implementation dependencies used by code generated from `agen` macros.
@@ -18,6 +18,9 @@ pub enum ClientError {
        message: String,
        retry_after: Option<Duration>,
    },
+    /// The provider rejected the request because it exceeded the model context window.
+    /// Classified only from a structured provider error code, never message text.
+    ContextWindowExceeded,
    /// A request lifecycle phase exceeded its hard timeout.
    Timeout {
        phase: &'static str,
@@ -48,6 +51,7 @@ impl fmt::Display for ClientError {
                }
                write!(f, ": {}", message)
            }
+            ClientError::ContextWindowExceeded => write!(f, "Model context window reached"),
            ClientError::Timeout { phase, timeout } => {
                write!(f, "{phase} timed out after {}s", timeout.as_secs())
            }
@@ -112,7 +116,10 @@ pub fn is_retryable(error: &ClientError) -> bool {
        ClientError::Api { status: None, .. } => false,
        ClientError::Timeout { .. } => true,
        ClientError::Http(e) => e.is_connect() || e.is_timeout(),
-        ClientError::Json(_) | ClientError::Sse(_) | ClientError::Config(_) => false,
+        ClientError::ContextWindowExceeded
+        | ClientError::Json(_)
+        | ClientError::Sse(_)
+        | ClientError::Config(_) => false,
    }
 }

@@ -431,13 +431,7 @@ fn api_error_code(error: &ClientError) -> Option<&str> {
 }

 fn is_context_length_exceeded(error: &ClientError) -> bool {
-    match error {
-        ClientError::Api { code, message, .. } => {
-            code.as_deref() == Some("context_length_exceeded")
-                || message.contains("context_length_exceeded")
-        }
-        _ => false,
-    }
+    matches!(error, ClientError::ContextWindowExceeded)
 }

 async fn response_with_timeout(
@@ -487,6 +481,9 @@ async fn classify_error_response(resp: reqwest::Response) -> ClientError {
            .and_then(|v| v.as_str())
            .unwrap_or(&text)
            .to_string();
+        if code.as_deref() == Some("context_length_exceeded") {
+            return ClientError::ContextWindowExceeded;
+        }
        ClientError::Api {
            status: Some(status),
            code,
@@ -9,7 +9,7 @@

 use std::{fmt, sync::Arc};

-use crate::tool::Attachment;
+use crate::tool::{Attachment, ToolResultDisposition};
 use base64::Engine as _;
 use serde::{Deserialize, Serialize};

@@ -121,6 +121,9 @@ pub enum Item {
        /// Detailed output (removed by pruning when old enough)
        #[serde(default, skip_serializing_if = "Option::is_none")]
        content: Option<String>,
+        /// Typed terminal state used for replay and recovery.
+        #[serde(default, skip_serializing_if = "ToolResultDisposition::is_success")]
+        disposition: ToolResultDisposition,
        /// Whether the tool result represents an execution error.
        #[serde(default, skip_serializing_if = "is_false")]
        is_error: bool,
@@ -261,7 +264,17 @@ impl Item {
        content: Option<String>,
        is_error: bool,
    ) -> Self {
-        Self::tool_result_item_with_attachments(call_id, summary, content, is_error, Vec::new())
+        Self::tool_result_item_with_disposition_and_attachments(
+            call_id,
+            summary,
+            content,
+            if is_error {
+                ToolResultDisposition::Error
+            } else {
+                ToolResultDisposition::Success
+            },
+            Vec::new(),
+        )
    }

    /// Create a tool result item with durable, prunable structured attachments.
@@ -272,11 +285,33 @@ impl Item {
        is_error: bool,
        attachments: Vec<Attachment>,
    ) -> Self {
+        Self::tool_result_item_with_disposition_and_attachments(
+            call_id,
+            summary,
+            content,
+            if is_error {
+                ToolResultDisposition::Error
+            } else {
+                ToolResultDisposition::Success
+            },
+            attachments,
+        )
+    }
+
+    pub fn tool_result_item_with_disposition_and_attachments(
+        call_id: impl Into<String>,
+        summary: impl Into<String>,
+        content: Option<String>,
+        disposition: ToolResultDisposition,
+        attachments: Vec<Attachment>,
+    ) -> Self {
+        let is_error = !disposition.is_success();
        Self::ToolResult {
            id: None,
            call_id: call_id.into(),
            summary: summary.into(),
            content,
+            disposition,
            is_error,
            attachments,
        }
@@ -19,7 +19,7 @@ mod private {
 /// - Editing message history (add, delete, clear)
 /// - Registering tools and hooks
 ///
-/// Can transition to [`Locked`] state via `Engine::lock()`.
+/// Can transition to [`Locked`] state via `Engine::lock(&history)`.
 ///
 /// # Examples
 ///
@@ -3,7 +3,14 @@
 //! Traits for defining tools callable by LLM.
 //! Usually auto-implemented using the `#[tool]` macro.

-use std::{collections::HashMap, fmt, sync::Arc};
+use std::{
+    collections::HashMap,
+    fmt,
+    future::Future,
+    pin::Pin,
+    sync::Arc,
+    task::{Context, Poll},
+};

 use async_trait::async_trait;
 use base64::{Engine as _, engine::general_purpose::STANDARD};
@@ -23,6 +30,12 @@ pub enum ToolError {
    /// Internal error
    #[error("Internal error: {0}")]
    Internal(String),
+    /// Cooperative cancellation completed with bounded terminal output.
+    #[error("Tool execution cancelled")]
+    Cancelled(ToolOutput),
+    /// Execution was interrupted with a confirmed bounded terminal output.
+    #[error("Tool execution interrupted")]
+    Interrupted(ToolOutput),
 }

 // =============================================================================
@@ -158,6 +171,28 @@ pub enum Attachment {
    Image(ImageAttachment),
 }

+/// Terminal disposition of one started tool call.
+///
+/// `Cancelled` means the tool confirmed cancellation. `OutcomeUnknown` means
+/// execution stopped without confirmation, so neither completion nor side
+/// effects may be inferred.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "snake_case")]
+pub enum ToolResultDisposition {
+    #[default]
+    Success,
+    Error,
+    Interrupted,
+    Cancelled,
+    OutcomeUnknown,
+}
+
+impl ToolResultDisposition {
+    pub const fn is_success(&self) -> bool {
+        matches!(self, Self::Success)
+    }
+}
+
 /// Tool execution result.
 ///
 /// Every output has a mandatory `summary` (1-2 lines) that persists in
@@ -322,6 +357,12 @@ impl ToolExecutionContext {
        }
    }

+    /// Identifies one live execution attempt without making the batch id a durable
+    /// replay or idempotency authority.
+    pub fn execution_id(&self) -> String {
+        format!("{}:{}", self.batch_id, self.call_id)
+    }
+
    /// Context for direct, non-engine calls in unit tests and low-level callers.
    pub fn direct() -> Self {
        Self::new("direct", "direct", 0)
@@ -334,6 +375,142 @@ impl Default for ToolExecutionContext {
    }
 }

+/// The provider-confirmed terminal result of one started tool execution.
+///
+/// `OutcomeUnknown` is reserved for an execution task that had to be force-closed
+/// or failed before the provider could confirm its terminal result.
+#[derive(Debug)]
+pub enum ToolExecutionTerminal {
+    Confirmed(Result<ToolOutput, ToolError>),
+    OutcomeUnknown,
+}
+
+/// The completion future paired with a [`ToolExecutionHandle`]. Dropping this
+/// future does not drop the provider execution: the spawned execution remains
+/// owned by its handle until it completes or is explicitly force-closed.
+pub struct ToolExecutionTerminalFuture {
+    task: tokio::task::JoinHandle<Result<ToolOutput, ToolError>>,
+}
+
+impl Future for ToolExecutionTerminalFuture {
+    type Output = ToolExecutionTerminal;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        match Pin::new(&mut self.task).poll(cx) {
+            Poll::Ready(Ok(result)) => Poll::Ready(ToolExecutionTerminal::Confirmed(result)),
+            Poll::Ready(Err(_)) => Poll::Ready(ToolExecutionTerminal::OutcomeUnknown),
+            Poll::Pending => Poll::Pending,
+        }
+    }
+}
+
+/// Live ownership and control for one started tool execution.
+///
+/// Execution, cancellation, and terminal confirmation remain provider-owned:
+/// this handle starts `Tool::execute`, delegates cooperative cancellation to
+/// `Tool::cancel_execution`, and treats execution-future completion as the
+/// provider's terminal confirmation. Agen may force-close only after its caller's
+/// deadline expires, at which point the outcome is necessarily unknown.
+#[derive(Clone)]
+pub struct ToolExecutionHandle {
+    inner: Arc<ToolExecutionHandleInner>,
+}
+
+struct ToolExecutionHandleInner {
+    tool: Arc<dyn Tool>,
+    context: ToolExecutionContext,
+    abort: tokio::task::AbortHandle,
+}
+
+impl Drop for ToolExecutionHandleInner {
+    fn drop(&mut self) {
+        // Losing the final live owner is an explicit forced close, never a
+        // best-effort detached provider future.
+        self.abort.abort();
+    }
+}
+
+impl fmt::Debug for ToolExecutionHandle {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("ToolExecutionHandle")
+            .field("call_id", &self.inner.context.call_id)
+            .field("batch_id", &self.inner.context.batch_id)
+            .finish_non_exhaustive()
+    }
+}
+
+impl ToolExecutionHandle {
+    pub fn start(
+        tool: Arc<dyn Tool>,
+        input_json: String,
+        context: ToolExecutionContext,
+    ) -> (Self, ToolExecutionTerminalFuture) {
+        let execution_tool = Arc::clone(&tool);
+        let execution_context = context.clone();
+        let task =
+            tokio::spawn(
+                async move { execution_tool.execute(&input_json, execution_context).await },
+            );
+        let abort = task.abort_handle();
+        (
+            Self {
+                inner: Arc::new(ToolExecutionHandleInner {
+                    tool,
+                    context,
+                    abort,
+                }),
+            },
+            ToolExecutionTerminalFuture { task },
+        )
+    }
+
+    pub fn context(&self) -> &ToolExecutionContext {
+        &self.inner.context
+    }
+
+    pub async fn cancel_before(&self, deadline: tokio::time::Instant) -> Result<(), ToolError> {
+        match tokio::time::timeout_at(
+            deadline,
+            self.inner.tool.cancel_execution(&self.inner.context),
+        )
+        .await
+        {
+            Ok(result) => result,
+            Err(_) => Err(ToolError::Internal(format!(
+                "tool cancellation request exceeded its deadline for call {}",
+                self.inner.context.call_id
+            ))),
+        }
+    }
+
+    pub fn force_close(&self) {
+        self.inner.abort.abort();
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ToolExecutionPolicy {
+    /// Time a pause waits for already-started providers to reach a natural safe
+    /// boundary before escalating to explicit cooperative cancellation.
+    pub pause_safe_boundary_timeout: std::time::Duration,
+    /// Maximum time allowed for a provider to accept one cooperative
+    /// cancellation request.
+    pub cancellation_request_timeout: std::time::Duration,
+    /// Maximum time allowed for all providers to confirm terminal results after
+    /// cancellation has been requested.
+    pub terminal_confirmation_timeout: std::time::Duration,
+}
+
+impl Default for ToolExecutionPolicy {
+    fn default() -> Self {
+        Self {
+            pause_safe_boundary_timeout: std::time::Duration::from_millis(100),
+            cancellation_request_timeout: std::time::Duration::from_millis(100),
+            terminal_confirmation_timeout: std::time::Duration::from_millis(500),
+        }
+    }
+}
+
 // =============================================================================
 // Tool trait
 // =============================================================================
@@ -402,6 +579,26 @@ pub trait Tool: Send + Sync {
        input_json: &str,
        ctx: ToolExecutionContext,
    ) -> Result<ToolOutput, ToolError>;
+
+    /// Request cooperative cancellation for one started call.
+    ///
+    /// Implementations that own cancellable provider operations should signal
+    /// every live execution identified by `call_id`, then let `execute` return
+    /// the confirmed bounded terminal output. Direct callers may use this
+    /// compatibility surface; Agen uses [`Tool::cancel_execution`] so providers
+    /// can bind cancellation to one exact live attempt.
+    async fn cancel(&self, _call_id: &str) -> Result<(), ToolError> {
+        Ok(())
+    }
+
+    /// Request cooperative cancellation for one exact started execution.
+    ///
+    /// The default preserves existing tools by delegating to `cancel(call_id)`.
+    /// Providers with their own execution registry should override this method
+    /// and key cancellation by [`ToolExecutionContext::execution_id`].
+    async fn cancel_execution(&self, ctx: &ToolExecutionContext) -> Result<(), ToolError> {
+        self.cancel(&ctx.call_id).await
+    }
 }

 // =============================================================================
@@ -429,6 +626,9 @@ pub struct ToolCall {
 pub struct ToolResult {
    /// Corresponding tool call ID
    pub tool_use_id: String,
+    /// Typed terminal state.
+    #[serde(default, skip_serializing_if = "ToolResultDisposition::is_success")]
+    pub disposition: ToolResultDisposition,
    /// Short summary (always kept in history)
    pub summary: String,
    /// Detailed output (prunable)
@@ -445,11 +645,20 @@ pub struct ToolResult {
 impl ToolResult {
    /// Create a success result from a [`ToolOutput`].
    pub fn from_output(tool_use_id: impl Into<String>, output: ToolOutput) -> Self {
+        Self::from_output_with_disposition(tool_use_id, output, ToolResultDisposition::Success)
+    }
+
+    pub fn from_output_with_disposition(
+        tool_use_id: impl Into<String>,
+        output: ToolOutput,
+        disposition: ToolResultDisposition,
+    ) -> Self {
        Self {
            tool_use_id: tool_use_id.into(),
+            disposition,
            summary: output.summary,
            content: output.content,
-            is_error: false,
+            is_error: !disposition.is_success(),
            attachments: output.attachments,
        }
    }
@@ -458,12 +667,28 @@ impl ToolResult {
    pub fn error(tool_use_id: impl Into<String>, message: impl Into<String>) -> Self {
        Self {
            tool_use_id: tool_use_id.into(),
+            disposition: ToolResultDisposition::Error,
            summary: message.into(),
            content: None,
            is_error: true,
            attachments: Vec::new(),
        }
    }
+
+    /// Close an execution whose completion and side effects cannot be confirmed.
+    pub fn outcome_unknown(tool_use_id: impl Into<String>) -> Self {
+        Self {
+            tool_use_id: tool_use_id.into(),
+            disposition: ToolResultDisposition::OutcomeUnknown,
+            summary: "Tool execution outcome unknown".to_string(),
+            content: Some(
+                "Execution was interrupted before completion could be confirmed. Completion and side effects are unknown."
+                    .to_string(),
+            ),
+            is_error: true,
+            attachments: Vec::new(),
+        }
+    }
 }

 #[cfg(test)]
@@ -0,0 +1,84 @@
+mod common;
+
+use agen::llm_client::event::{Event, ResponseStatus, StatusEvent};
+use agen::{Engine, EngineError, History, HistoryEntry, Item, Role};
+use common::MockLlmClient;
+
+fn completed_text_events(text: &str) -> Vec<Event> {
+    vec![
+        Event::text_block_start(0),
+        Event::text_delta(0, text),
+        Event::text_block_stop(0, None),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]
+}
+
+#[tokio::test]
+async fn run_preserves_item_annotations_without_projecting_them() {
+    let client = MockLlmClient::new(completed_text_events("assistant reply"));
+    let engine = Engine::<_, agen::state::Mutable, String>::new_annotated(client);
+    let mut history = History::<String>::new();
+    let mut next = 0usize;
+    let mut annotate = |item: &Item| {
+        next += 1;
+        let kind = match item {
+            Item::Message { role, .. } => match role {
+                Role::User => "user",
+                Role::Assistant => "assistant",
+                Role::System => "system",
+            },
+            Item::ToolCall { .. } => "tool_call",
+            Item::ToolResult { .. } => "tool_result",
+            Item::Reasoning { .. } => "reasoning",
+        };
+        Ok(format!("{next}:{kind}"))
+    };
+
+    let output = engine
+        .run_with_annotation(&mut history, "hello", &mut annotate)
+        .await;
+
+    assert!(matches!(output.result, agen::EngineRunExit::Finished));
+    assert_eq!(history.len(), 2);
+    assert_eq!(history.entries()[0].annotation, "1:user");
+    assert_eq!(history.entries()[1].annotation, "2:assistant");
+    assert_eq!(history.items_cloned().len(), 2);
+}
+
+#[test]
+fn append_failure_does_not_make_item_live() {
+    let client = MockLlmClient::new(vec![]);
+    let mut engine = Engine::<_, agen::state::Mutable, usize>::new_annotated(client);
+    let mut history = History::<usize>::new();
+    let mut fail = |_item: &Item| Err("commit failed".to_string());
+
+    let err = engine
+        .append_history_with(&mut history, [Item::user_message("uncommitted")], &mut fail)
+        .unwrap_err();
+
+    assert!(matches!(err, EngineError::HistoryAppend(message) if message == "commit failed"));
+    assert!(history.is_empty());
+}
+
+#[test]
+fn replacement_keeps_items_and_annotations_together() {
+    let mut history = History::from_entries(vec![
+        HistoryEntry::new(Item::user_message("old"), "old-ann".to_string()),
+        HistoryEntry::new(Item::user_message("second"), "second-ann".to_string()),
+    ]);
+
+    history.truncate(1);
+    assert_eq!(history.entries()[0].item.as_text(), Some("old"));
+    assert_eq!(history.entries()[0].annotation, "old-ann");
+
+    let previous = history.replace_entries(vec![HistoryEntry::new(
+        Item::user_message("restored"),
+        "restored-ann".to_string(),
+    )]);
+
+    assert_eq!(previous.len(), 1);
+    assert_eq!(history.entries()[0].item.as_text(), Some("restored"));
+    assert_eq!(history.entries()[0].annotation, "restored-ann");
+}
@@ -58,6 +58,7 @@ async fn test_callback_llm_retry_event() {
        max_attempts: 2,
        total_timeout: Duration::from_secs(1),
    });
+    let mut history = agen::History::new();

    let notices = Arc::new(Mutex::new(Vec::new()));
    let sink = notices.clone();
@@ -65,8 +66,11 @@ async fn test_callback_llm_retry_event() {
        sink.lock().unwrap().push((llm_call, notice.clone()));
    });

-    let result = engine.run("retry once").await;
-    assert!(result.is_ok(), "engine should succeed after one retry");
+    let result = engine.run(&mut history, "retry once").await;
+    assert!(
+        matches!(result.result, agen::EngineRunExit::Finished),
+        "engine should succeed after one retry"
+    );

    let notices = notices.lock().unwrap();
    assert_eq!(notices.len(), 1);
@@ -91,6 +95,7 @@ async fn test_callback_text_block_events() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    let text_deltas = Arc::new(Mutex::new(Vec::new()));
    let text_completes = Arc::new(Mutex::new(Vec::new()));
@@ -108,9 +113,12 @@ async fn test_callback_text_block_events() {
        });
    });

-    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let result = engine.run("Greet me").await;
-    assert!(result.is_ok(), "Engine should complete");
+    // Mutable::run consumes self, returns (Locked, EngineRunExit)
+    let result = engine.run(&mut history, "Greet me").await;
+    assert!(
+        matches!(result.result, agen::EngineRunExit::Finished),
+        "Engine should complete"
+    );

    let deltas = text_deltas.lock().unwrap();
    assert_eq!(deltas.len(), 2);
@@ -137,6 +145,7 @@ async fn test_callback_tool_call_complete() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    let tool_starts = Arc::new(Mutex::new(Vec::<(String, String)>::new()));
    let tool_completes = Arc::new(Mutex::new(Vec::new()));
@@ -154,8 +163,8 @@ async fn test_callback_tool_call_complete() {
        });
    });

-    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let _ = engine.run("Weather please").await;
+    // Mutable::run consumes self, returns (Locked, EngineRunExit)
+    let _ = engine.run(&mut history, "Weather please").await;

    let starts = tool_starts.lock().unwrap();
    assert_eq!(starts.len(), 1);
@@ -183,6 +192,7 @@ async fn test_callback_turn_events() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    let turn_starts = Arc::new(Mutex::new(Vec::new()));
    let turn_ends = Arc::new(Mutex::new(Vec::new()));
@@ -197,9 +207,9 @@ async fn test_callback_turn_events() {
        ends.lock().unwrap().push(turn);
    });

-    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let result = engine.run("Do something").await;
-    assert!(result.is_ok());
+    // Mutable::run consumes self, returns (Locked, EngineRunExit)
+    let result = engine.run(&mut history, "Do something").await;
+    assert!(matches!(result.result, agen::EngineRunExit::Finished));

    let starts = turn_starts.lock().unwrap();
    let ends = turn_ends.lock().unwrap();
@@ -254,6 +264,7 @@ async fn test_callback_tool_result_events() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    engine.register_tool(fixed_tool(
        "fixed",
@@ -276,7 +287,7 @@ async fn test_callback_tool_result_events() {
        ));
    });

-    let _ = engine.run("call it").await;
+    let _ = engine.run(&mut history, "call it").await;

    let observed = captured.lock().unwrap();
    assert_eq!(observed.len(), 1);
@@ -330,6 +341,7 @@ async fn test_callback_tool_result_error_path() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    engine.register_tool(erroring_tool("erroring", "boom"));

@@ -345,7 +357,7 @@ async fn test_callback_tool_result_error_path() {
        ));
    });

-    let _ = engine.run("fail it").await;
+    let _ = engine.run(&mut history, "fail it").await;

    let observed = captured.lock().unwrap();
    assert_eq!(observed.len(), 1);
@@ -374,6 +386,7 @@ async fn test_callback_usage_events() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    let usage_events = Arc::new(Mutex::new(Vec::new()));

@@ -382,8 +395,8 @@ async fn test_callback_usage_events() {
        usages.lock().unwrap().push(event.clone());
    });

-    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let _ = engine.run("Hello").await;
+    // Mutable::run consumes self, returns (Locked, EngineRunExit)
+    let _ = engine.run(&mut history, "Hello").await;

    let usages = usage_events.lock().unwrap();
    assert_eq!(usages.len(), 1);
@@ -19,6 +19,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 pub struct MockLlmClient {
    responses: Arc<Vec<Vec<Event>>>,
    call_count: Arc<AtomicUsize>,
+    requests: Arc<Mutex<Vec<Request>>>,
 }

 impl MockLlmClient {
@@ -30,6 +31,7 @@ impl MockLlmClient {
        Self {
            responses: Arc::new(responses),
            call_count: Arc::new(AtomicUsize::new(0)),
+            requests: Arc::new(Mutex::new(Vec::new())),
        }
    }

@@ -41,6 +43,10 @@ impl MockLlmClient {
    pub fn event_count(&self) -> usize {
        self.responses.iter().map(|v| v.len()).sum()
    }
+
+    pub fn requests(&self) -> Vec<Request> {
+        self.requests.lock().unwrap().clone()
+    }
 }

 #[async_trait]
@@ -51,8 +57,9 @@ impl LlmClient for MockLlmClient {

    async fn stream(
        &self,
-        _request: Request,
+        request: Request,
    ) -> Result<Pin<Box<dyn Stream<Item = Result<Event, ClientError>> + Send>>, ClientError> {
+        self.requests.lock().unwrap().push(request);
        let count = self.call_count.fetch_add(1, Ordering::SeqCst);
        if count >= self.responses.len() {
            return Err(ClientError::Api {
@@ -134,11 +134,15 @@ async fn test_engine_simple_text_response() {

    let client = MockLlmClient::from_fixture(&fixture_path).unwrap();
    let engine = Engine::new(client);
+    let mut history = agen::History::new();

    // Send a simple message (Mutable::run consumes self, returns tuple)
-    let result = engine.run("Hello").await;
+    let result = engine.run(&mut history, "Hello").await;

-    assert!(result.is_ok(), "Engine should complete successfully");
+    assert!(
+        matches!(result.result, agen::EngineRunExit::Finished),
+        "Engine should complete successfully"
+    );
 }

 /// Verify that Engine can correctly process responses containing tool calls
@@ -156,6 +160,7 @@ async fn test_engine_tool_call() {

    let client = MockLlmClient::from_fixture(&fixture_path).unwrap();
    let mut engine = Engine::new(client);
+    let mut history = agen::History::new();

    // Register tool
    let weather_tool = MockWeatherTool::new();
@@ -163,7 +168,9 @@ async fn test_engine_tool_call() {
    engine.register_tool(weather_tool.definition());

    // Send message (Mutable::run consumes self, returns tuple)
-    let _result = engine.run("What's the weather in Tokyo?").await;
+    let _result = engine
+        .run(&mut history, "What's the weather in Tokyo?")
+        .await;

    // Verify tool was called
    // Note: max_turns=1 so no request is sent after tool result
@@ -195,11 +202,15 @@ async fn test_engine_with_programmatic_events() {

    let client = MockLlmClient::new(events);
    let engine = Engine::new(client);
+    let mut history = agen::History::new();

    // Mutable::run consumes self, returns tuple
-    let result = engine.run("Greet me").await;
+    let result = engine.run(&mut history, "Greet me").await;

-    assert!(result.is_ok(), "Engine should complete successfully");
+    assert!(
+        matches!(result.result, agen::EngineRunExit::Finished),
+        "Engine should complete successfully"
+    );
 }

 /// Verify that ToolCallCollector correctly collects ToolCall from ToolUse block events
@@ -9,9 +9,12 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::{Arc, Mutex};

 use agen::Item;
+use agen::interceptor::{
+    Interceptor, PreRequestAction, PreToolAction, ToolCallInfo, TurnEndAction,
+};
 use agen::llm_client::event::{Event, ResponseStatus, StatusEvent};
 use agen::tool::{Tool, ToolDefinition, ToolError, ToolMeta, ToolOutput};
-use agen::{Engine, EngineError};
+use agen::{Engine, EngineError, EngineRunExit, History, StopReason};
 use async_trait::async_trait;
 use common::MockLlmClient;

@@ -39,36 +42,37 @@ fn test_mutable_set_system_prompt() {
 fn test_mutable_history_manipulation() {
    let client = MockLlmClient::new(vec![]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    // Initial state is empty
-    assert!(engine.history().is_empty());
+    assert!(history.is_empty());

    // Add to history
    engine
-        .append_history(vec![Item::user_message("Hello")])
+        .append_history(&mut history, vec![Item::user_message("Hello")])
        .unwrap();
    engine
-        .append_history(vec![Item::assistant_message("Hi there!")])
+        .append_history(&mut history, vec![Item::assistant_message("Hi there!")])
        .unwrap();
-    assert_eq!(engine.history().len(), 2);
+    assert_eq!(history.len(), 2);

    // Append to history via the callback-aware API.
    engine
-        .append_history(vec![Item::user_message("How are you?")])
+        .append_history(&mut history, vec![Item::user_message("How are you?")])
        .unwrap();
-    assert_eq!(engine.history().len(), 3);
+    assert_eq!(history.len(), 3);

    // Clear history
-    engine.clear_history();
-    assert!(engine.history().is_empty());
+    engine.clear_history(&mut history);
+    assert!(history.is_empty());

    // Set history
    let items = vec![
        Item::user_message("Test"),
        Item::assistant_message("Response"),
    ];
-    engine.set_history(items);
-    assert_eq!(engine.history().len(), 2);
+    engine.set_history(&mut history, items);
+    assert_eq!(history.len(), 2);
 }

 /// Verify that Engine can be constructed using builder pattern
@@ -76,9 +80,10 @@ fn test_mutable_history_manipulation() {
 fn test_mutable_builder_pattern() {
    let client = MockLlmClient::new(vec![]);
    let engine = Engine::new(client).system_prompt("System prompt");
+    let history: History = History::new();

    assert_eq!(engine.get_system_prompt(), Some("System prompt"));
-    assert!(engine.history().is_empty());
+    assert!(history.is_empty());
 }

 /// Verify that multiple items can be added with append_history and callbacks fire.
@@ -88,6 +93,7 @@ fn test_mutable_append_history() {
    let observed = Arc::new(Mutex::new(Vec::new()));
    let observed_for_callback = Arc::clone(&observed);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    engine.on_history_append(move |item| {
        if let Some(text) = item.as_text() {
            observed_for_callback.lock().unwrap().push(text.to_string());
@@ -96,18 +102,21 @@ fn test_mutable_append_history() {
    });

    engine
-        .append_history(vec![Item::user_message("First")])
+        .append_history(&mut history, vec![Item::user_message("First")])
        .unwrap();

    engine
-        .append_history(vec![
+        .append_history(
+            &mut history,
+            vec![
                Item::assistant_message("Response 1"),
                Item::user_message("Second"),
                Item::assistant_message("Response 2"),
-        ])
+            ],
+        )
        .unwrap();

-    assert_eq!(engine.history().len(), 4);
+    assert_eq!(history.len(), 4);
    assert_eq!(
        observed.lock().unwrap().as_slice(),
        ["First", "Response 1", "Second", "Response 2"]
@@ -182,6 +191,7 @@ async fn history_append_failure_stops_before_tool_execution() {
    ]);
    let tool = CountingTool::new("count_tool");
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    engine.register_tool(tool.definition());
    engine.on_history_append(|item| {
        if item.is_tool_call() {
@@ -191,15 +201,15 @@ async fn history_append_failure_stops_before_tool_execution() {
        }
    });

-    let mut engine = engine.lock();
-    let error = engine.run("use the tool").await.unwrap_err();
+    let mut engine = engine.lock(&history);
+    let exit = engine.run(&mut history, "use the tool").await;

    assert!(
-        matches!(error, EngineError::HistoryAppend(ref message) if message == "simulated ENOSPC")
+        matches!(exit, EngineRunExit::Interrupted(StopReason::Unexpected(EngineError::HistoryAppend(ref message))) if message == "simulated ENOSPC")
    );
    assert_eq!(tool.call_count(), 0);
-    assert_eq!(engine.history().len(), 1);
-    assert_eq!(engine.history()[0].as_text(), Some("use the tool"));
+    assert_eq!(history.len(), 1);
+    assert_eq!(history.entries()[0].item.as_text(), Some("use the tool"));
 }

 // =============================================================================
@@ -211,21 +221,22 @@ async fn history_append_failure_stops_before_tool_execution() {
 fn test_lock_transition() {
    let client = MockLlmClient::new(vec![]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    engine.set_system_prompt("System");
    engine
-        .append_history(vec![Item::user_message("Hello")])
+        .append_history(&mut history, vec![Item::user_message("Hello")])
        .unwrap();
    engine
-        .append_history(vec![Item::assistant_message("Hi")])
+        .append_history(&mut history, vec![Item::assistant_message("Hi")])
        .unwrap();

    // Lock
-    let locked_engine = engine.lock();
+    let locked_engine = engine.lock(&history);

    // History and system prompt are still accessible in Locked state
    assert_eq!(locked_engine.get_system_prompt(), Some("System"));
-    assert_eq!(locked_engine.history().len(), 2);
+    assert_eq!(history.len(), 2);
    assert_eq!(locked_engine.locked_prefix_len(), 2);
 }

@@ -234,21 +245,22 @@ fn test_lock_transition() {
 fn test_unlock_transition() {
    let client = MockLlmClient::new(vec![]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    engine
-        .append_history(vec![Item::user_message("Hello")])
+        .append_history(&mut history, vec![Item::user_message("Hello")])
        .unwrap();
-    let locked_engine = engine.lock();
+    let locked_engine = engine.lock(&history);

    // Unlock
    let mut engine = locked_engine.unlock();

    // History operations are available again in Mutable state
    engine
-        .append_history(vec![Item::assistant_message("Hi")])
+        .append_history(&mut history, vec![Item::assistant_message("Hi")])
        .unwrap();
-    engine.clear_history();
-    assert!(engine.history().is_empty());
+    engine.clear_history(&mut history);
+    assert!(history.is_empty());
 }

 // =============================================================================
@@ -269,20 +281,20 @@ async fn test_mutable_run_updates_history() -> Result<(), EngineError> {

    let client = MockLlmClient::new(events);
    let engine = Engine::new(client);
+    let mut history: History = History::new();

    // Execute (Mutable::run consumes self, returns EngineRunOutput)
-    let out = engine.run("Hi there").await?;
-    let engine = out.engine;
+    let _out = engine.run(&mut history, "Hi there").await;

    // History is updated
-    let history = engine.history();
+    let entries = history.entries();
    assert_eq!(history.len(), 2); // user + assistant

    // User message
-    assert_eq!(history[0].as_text(), Some("Hi there"));
+    assert_eq!(entries[0].item.as_text(), Some("Hi there"));

    // Assistant message
-    assert_eq!(history[1].as_text(), Some("Hello, I'm an assistant!"));
+    assert_eq!(entries[1].item.as_text(), Some("Hello, I'm an assistant!"));

    Ok(())
 }
@@ -313,35 +325,36 @@ async fn test_locked_multi_turn_history_accumulation() {
    ]);

    let engine = Engine::new(client).system_prompt("You are helpful.");
+    let mut history: History = History::new();

    // Lock (after setting system prompt)
-    let mut locked_engine = engine.lock();
+    let mut locked_engine = engine.lock(&history);
    assert_eq!(locked_engine.locked_prefix_len(), 0); // No items yet

    // Turn 1
-    let result1 = locked_engine.run("Hello!").await;
-    assert!(result1.is_ok());
-    assert_eq!(locked_engine.history().len(), 2); // user + assistant
+    let result1 = locked_engine.run(&mut history, "Hello!").await;
+    assert!(matches!(result1, EngineRunExit::Finished));
+    assert_eq!(history.len(), 2); // user + assistant

    // Turn 2
-    let result2 = locked_engine.run("Can you help me?").await;
-    assert!(result2.is_ok());
-    assert_eq!(locked_engine.history().len(), 4); // 2 * (user + assistant)
+    let result2 = locked_engine.run(&mut history, "Can you help me?").await;
+    assert!(matches!(result2, EngineRunExit::Finished));
+    assert_eq!(history.len(), 4); // 2 * (user + assistant)

    // Verify history contents
-    let history = locked_engine.history();
+    let entries = history.entries();

    // Turn 1 user message
-    assert_eq!(history[0].as_text(), Some("Hello!"));
+    assert_eq!(entries[0].item.as_text(), Some("Hello!"));

    // Turn 1 assistant message
-    assert_eq!(history[1].as_text(), Some("Nice to meet you!"));
+    assert_eq!(entries[1].item.as_text(), Some("Nice to meet you!"));

    // Turn 2 user message
-    assert_eq!(history[2].as_text(), Some("Can you help me?"));
+    assert_eq!(entries[2].item.as_text(), Some("Can you help me?"));

    // Turn 2 assistant message
-    assert_eq!(history[3].as_text(), Some("I can help with that."));
+    assert_eq!(entries[3].item.as_text(), Some("I can help with that."));
 }

 /// Verify that locked_prefix_len correctly records history length at lock time
@@ -367,26 +380,33 @@ async fn test_locked_prefix_len_tracking() {
    ]);

    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    // Add items beforehand
    engine
-        .append_history(vec![Item::user_message("Pre-existing message 1")])
+        .append_history(
+            &mut history,
+            vec![Item::user_message("Pre-existing message 1")],
+        )
        .unwrap();
    engine
-        .append_history(vec![Item::assistant_message("Pre-existing response 1")])
+        .append_history(
+            &mut history,
+            vec![Item::assistant_message("Pre-existing response 1")],
+        )
        .unwrap();

-    assert_eq!(engine.history().len(), 2);
+    assert_eq!(history.len(), 2);

    // Lock
-    let mut locked_engine = engine.lock();
+    let mut locked_engine = engine.lock(&history);
    assert_eq!(locked_engine.locked_prefix_len(), 2); // 2 items at lock time

    // Execute turn
-    locked_engine.run("New message").await.unwrap();
+    locked_engine.run(&mut history, "New message").await;

    // History grows but locked_prefix_len remains unchanged
-    assert_eq!(locked_engine.history().len(), 4); // 2 + 2
+    assert_eq!(history.len(), 4); // 2 + 2
    assert_eq!(locked_engine.locked_prefix_len(), 2); // Unchanged
 }

@@ -413,18 +433,22 @@ async fn test_turn_count_increment() -> Result<(), EngineError> {
    ]);

    let engine = Engine::new(client);
+    let mut history: History = History::new();

    assert_eq!(engine.turn_count(), 0);
    assert_eq!(engine.llm_call_count(), 0);

    // First run consumes Mutable, returns EngineRunOutput
-    let mut engine = engine.run("First").await?.engine;
+    let mut engine = engine.run(&mut history, "First").await.engine;
    assert_eq!(engine.turn_count(), 1);
    // Retry not yet implemented → AgentTurn:LlmCall is 1:1.
    assert_eq!(engine.llm_call_count(), 1);

    // Subsequent runs on Locked take &mut self
-    engine.run("Second").await?;
+    assert!(matches!(
+        engine.run(&mut history, "Second").await,
+        EngineRunExit::Finished
+    ));
    assert_eq!(engine.turn_count(), 2);
    assert_eq!(engine.llm_call_count(), 2);

@@ -444,28 +468,29 @@ async fn test_unlock_edit_relock() {
    ]]);

    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    engine
-        .append_history(vec![
-            Item::user_message("Hello"),
-            Item::assistant_message("Hi"),
-        ])
+        .append_history(
+            &mut history,
+            vec![Item::user_message("Hello"), Item::assistant_message("Hi")],
+        )
        .unwrap();

    // Lock -> Unlock
-    let locked = engine.lock();
+    let locked = engine.lock(&history);
    assert_eq!(locked.locked_prefix_len(), 2);

    let mut unlocked = locked.unlock();

    // Edit history
-    unlocked.clear_history();
+    unlocked.clear_history(&mut history);
    unlocked
-        .append_history(vec![Item::user_message("Fresh start")])
+        .append_history(&mut history, vec![Item::user_message("Fresh start")])
        .unwrap();

    // Re-lock
-    let relocked = unlocked.lock();
-    assert_eq!(relocked.history().len(), 1);
+    let relocked = unlocked.lock(&history);
+    assert_eq!(history.len(), 1);
    assert_eq!(relocked.locked_prefix_len(), 1);
 }

@@ -508,19 +533,26 @@ async fn test_lock_unlock_relock_tools_remain_effective() {
    ]);

    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let tool_a = CountingTool::new("tool_a");
    engine.register_tool(tool_a.definition());

-    let mut locked = engine.lock();
-    locked.run("first").await.expect("first run");
+    let mut locked = engine.lock(&history);
+    assert!(matches!(
+        locked.run(&mut history, "first").await,
+        EngineRunExit::Finished
+    ));
    assert_eq!(tool_a.call_count(), 1, "tool_a should be called once");

    let mut unlocked = locked.unlock();
    let tool_b = CountingTool::new("tool_b");
    unlocked.register_tool(tool_b.definition());

-    let mut relocked = unlocked.lock();
-    relocked.run("second").await.expect("second run");
+    let mut relocked = unlocked.lock(&history);
+    assert!(matches!(
+        relocked.run(&mut history, "second").await,
+        EngineRunExit::Finished
+    ));

    assert_eq!(tool_a.call_count(), 1, "tool_a should not be called again");
    assert_eq!(tool_b.call_count(), 1, "tool_b should be called once");
@@ -535,8 +567,9 @@ async fn test_lock_unlock_relock_tools_remain_effective() {
 fn test_system_prompt_preserved_in_locked_state() {
    let client = MockLlmClient::new(vec![]);
    let engine = Engine::new(client).system_prompt("Important system prompt");
+    let history: History = History::new();

-    let locked = engine.lock();
+    let locked = engine.lock(&history);
    assert_eq!(locked.get_system_prompt(), Some("Important system prompt"));

    let unlocked = locked.unlock();
@@ -551,13 +584,228 @@ fn test_system_prompt_preserved_in_locked_state() {
 fn test_system_prompt_change_after_unlock() {
    let client = MockLlmClient::new(vec![]);
    let engine = Engine::new(client).system_prompt("Original prompt");
+    let history: History = History::new();

-    let locked = engine.lock();
+    let locked = engine.lock(&history);
    let mut unlocked = locked.unlock();

    unlocked.set_system_prompt("New prompt");
    assert_eq!(unlocked.get_system_prompt(), Some("New prompt"));

-    let relocked = unlocked.lock();
+    let relocked = unlocked.lock(&history);
    assert_eq!(relocked.get_system_prompt(), Some("New prompt"));
 }
+
+fn completed_text_events() -> Vec<Event> {
+    vec![
+        Event::text_block_start(0),
+        Event::text_delta(0, "done"),
+        Event::text_block_stop(0, None),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]
+}
+
+struct YieldOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for YieldOnce {
+    async fn pre_llm_request(&self, _context: &mut Vec<Item>) -> PreRequestAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            PreRequestAction::Yield
+        } else {
+            PreRequestAction::Continue
+        }
+    }
+}
+
+struct PauseToolOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for PauseToolOnce {
+    async fn pre_tool_call(&self, _info: &mut ToolCallInfo) -> PreToolAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            PreToolAction::Pause
+        } else {
+            PreToolAction::Continue
+        }
+    }
+}
+
+struct ContinueTurnOnce {
+    calls: AtomicUsize,
+}
+
+#[async_trait]
+impl Interceptor for ContinueTurnOnce {
+    async fn on_turn_end(&self, _history: &[Item]) -> TurnEndAction {
+        if self.calls.fetch_add(1, Ordering::SeqCst) == 0 {
+            TurnEndAction::ContinueWithMessages(vec![Item::system_message("continue")])
+        } else {
+            TurnEndAction::Finish
+        }
+    }
+}
+
+#[tokio::test]
+async fn max_turns_is_scoped_to_each_fresh_run() {
+    let mut history: History = History::new();
+    let responses = vec![completed_text_events(), completed_text_events()];
+    let mut engine = Engine::new(MockLlmClient::with_responses(responses));
+    engine.set_max_turns(Some(1));
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.run(&mut history, "first").await,
+        EngineRunExit::Finished
+    ));
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+
+    assert!(matches!(
+        engine.run(&mut history, "second").await,
+        EngineRunExit::Finished
+    ));
+    assert_eq!(engine.turn_count(), 2);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn yielded_resume_keeps_the_same_unspent_turn_budget() {
+    let mut history: History = History::new();
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_interceptor(YieldOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.run(&mut history, "start").await,
+        EngineRunExit::Yielded
+    ));
+    assert_eq!(engine.turn_count(), 0);
+    assert_eq!(engine.active_run_turn_count(), Some(0));
+
+    assert!(matches!(
+        engine.resume(&mut history).await,
+        EngineRunExit::Finished
+    ));
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn paused_tool_resume_does_not_reset_the_consumed_turn_budget() {
+    let mut history: History = History::new();
+    let events = vec![
+        Event::tool_use_start(0, "call_1", "count_tool"),
+        Event::tool_input_delta(0, "{}"),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ];
+    let tool = CountingTool::new("count_tool");
+    let mut engine = Engine::new(MockLlmClient::new(events));
+    engine.set_max_turns(Some(1));
+    engine.register_tool(tool.definition());
+    engine.set_interceptor(PauseToolOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.run(&mut history, "call it").await,
+        EngineRunExit::Paused
+    ));
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), Some(1));
+    assert_eq!(tool.call_count(), 0);
+
+    assert!(matches!(
+        engine.resume(&mut history).await,
+        EngineRunExit::Interrupted(StopReason::LimitReached)
+    ));
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+    assert_eq!(tool.call_count(), 1, "the consumed turn's tool still runs");
+}
+
+#[tokio::test]
+async fn fresh_input_abandons_a_paused_run_and_starts_a_new_budget() {
+    let mut history: History = History::new();
+    let tool_events = vec![
+        Event::tool_use_start(0, "call_1", "count_tool"),
+        Event::tool_input_delta(0, "{}"),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ];
+    let client = MockLlmClient::with_responses(vec![tool_events, completed_text_events()]);
+    let tool = CountingTool::new("count_tool");
+    let mut engine = Engine::new(client);
+    engine.set_max_turns(Some(1));
+    engine.register_tool(tool.definition());
+    engine.set_interceptor(PauseToolOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.run(&mut history, "pause").await,
+        EngineRunExit::Paused
+    ));
+    assert_eq!(engine.active_run_turn_count(), Some(1));
+
+    assert!(matches!(
+        engine.run(&mut history, "replace").await,
+        EngineRunExit::Finished
+    ));
+    assert_eq!(engine.turn_count(), 2);
+    assert_eq!(engine.active_run_turn_count(), None);
+    assert_eq!(tool.call_count(), 1, "pending-tool semantics are unchanged");
+}
+
+#[tokio::test]
+async fn interceptor_continuation_consumes_the_logical_run_budget() {
+    let mut history: History = History::new();
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_interceptor(ContinueTurnOnce {
+        calls: AtomicUsize::new(0),
+    });
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.run(&mut history, "start").await,
+        EngineRunExit::Interrupted(StopReason::LimitReached)
+    ));
+    assert_eq!(engine.turn_count(), 1);
+    assert_eq!(engine.llm_call_count(), 1);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
+
+#[tokio::test]
+async fn restored_active_run_budget_is_enforced_before_another_llm_call() {
+    let mut history: History = History::new();
+    let mut engine = Engine::new(MockLlmClient::new(completed_text_events()));
+    engine.set_max_turns(Some(1));
+    engine.set_turn_count(7);
+    engine.set_active_run_turn_count(Some(1));
+    let mut engine = engine.lock(&history);
+
+    assert!(matches!(
+        engine.resume(&mut history).await,
+        EngineRunExit::Interrupted(StopReason::LimitReached)
+    ));
+    assert_eq!(engine.turn_count(), 7);
+    assert_eq!(engine.llm_call_count(), 0);
+    assert_eq!(engine.active_run_turn_count(), None);
+}
@@ -6,12 +6,13 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};

-use agen::Engine;
 use agen::interceptor::{Interceptor, PostToolAction, PreToolAction, ToolCallInfo, ToolResultInfo};
 use agen::llm_client::event::{Event, ResponseStatus, StatusEvent};
 use agen::tool::{
    Tool, ToolDefinition, ToolError, ToolExecutionContext, ToolMeta, ToolOutput, ToolResult,
+    ToolResultDisposition,
 };
+use agen::{Engine, History, Item, ToolExecutionPolicy};
 use async_trait::async_trait;

 mod common;
@@ -70,6 +71,144 @@ impl Tool for SlowTool {
    }
 }

+#[derive(Clone)]
+struct FirstAttemptHangsTool {
+    calls: Arc<AtomicUsize>,
+}
+
+impl FirstAttemptHangsTool {
+    fn new() -> Self {
+        Self {
+            calls: Arc::new(AtomicUsize::new(0)),
+        }
+    }
+
+    fn definition(&self) -> ToolDefinition {
+        let tool = self.clone();
+        Arc::new(move || {
+            let meta = ToolMeta::new("hang_once")
+                .description("Hangs on the first execution attempt")
+                .input_schema(serde_json::json!({"type": "object"}));
+            (meta, Arc::new(tool.clone()) as Arc<dyn Tool>)
+        })
+    }
+
+    fn call_count(&self) -> usize {
+        self.calls.load(Ordering::SeqCst)
+    }
+}
+
+#[async_trait]
+impl Tool for FirstAttemptHangsTool {
+    async fn execute(
+        &self,
+        _input_json: &str,
+        _ctx: ToolExecutionContext,
+    ) -> Result<ToolOutput, ToolError> {
+        let attempt = self.calls.fetch_add(1, Ordering::SeqCst);
+        if attempt == 0 {
+            std::future::pending::<()>().await;
+        }
+        Ok("completed on retry".to_string().into())
+    }
+}
+
+#[derive(Clone)]
+struct CooperativeCancelTool {
+    calls: Arc<AtomicUsize>,
+    cancelled: Arc<tokio::sync::Notify>,
+}
+
+impl CooperativeCancelTool {
+    fn new() -> Self {
+        Self {
+            calls: Arc::new(AtomicUsize::new(0)),
+            cancelled: Arc::new(tokio::sync::Notify::new()),
+        }
+    }
+
+    fn definition(&self) -> ToolDefinition {
+        let tool = self.clone();
+        Arc::new(move || {
+            let meta = ToolMeta::new("cooperative")
+                .description("Returns bounded progress after cancellation")
+                .input_schema(serde_json::json!({"type": "object"}));
+            (meta, Arc::new(tool.clone()) as Arc<dyn Tool>)
+        })
+    }
+}
+
+#[async_trait]
+impl Tool for CooperativeCancelTool {
+    async fn execute(
+        &self,
+        _input_json: &str,
+        _ctx: ToolExecutionContext,
+    ) -> Result<ToolOutput, ToolError> {
+        self.calls.fetch_add(1, Ordering::SeqCst);
+        self.cancelled.notified().await;
+        Err(ToolError::Cancelled(ToolOutput {
+            summary: "cooperative command cancelled".to_string(),
+            content: Some("stdout before cancellation\nstderr before cancellation".to_string()),
+            attachments: Vec::new(),
+        }))
+    }
+
+    async fn cancel(&self, _call_id: &str) -> Result<(), ToolError> {
+        self.cancelled.notify_one();
+        Ok(())
+    }
+}
+
+#[derive(Clone)]
+struct SafePauseTool {
+    calls: Arc<AtomicUsize>,
+    cancellations: Arc<AtomicUsize>,
+    release: Arc<tokio::sync::Notify>,
+}
+
+impl SafePauseTool {
+    fn new() -> Self {
+        Self {
+            calls: Arc::new(AtomicUsize::new(0)),
+            cancellations: Arc::new(AtomicUsize::new(0)),
+            release: Arc::new(tokio::sync::Notify::new()),
+        }
+    }
+
+    fn definition(&self) -> ToolDefinition {
+        let tool = self.clone();
+        Arc::new(move || {
+            let meta = ToolMeta::new("safe_pause")
+                .description("Waits for a safe-boundary release")
+                .input_schema(serde_json::json!({"type": "object"}));
+            (meta, Arc::new(tool.clone()) as Arc<dyn Tool>)
+        })
+    }
+}
+
+#[async_trait]
+impl Tool for SafePauseTool {
+    async fn execute(
+        &self,
+        _input_json: &str,
+        _ctx: ToolExecutionContext,
+    ) -> Result<ToolOutput, ToolError> {
+        self.calls.fetch_add(1, Ordering::SeqCst);
+        self.release.notified().await;
+        Ok(ToolOutput {
+            summary: "safe-boundary complete".to_string(),
+            content: Some("safe-boundary complete".to_string()),
+            attachments: Vec::new(),
+        })
+    }
+
+    async fn cancel(&self, _call_id: &str) -> Result<(), ToolError> {
+        self.cancellations.fetch_add(1, Ordering::SeqCst);
+        Ok(())
+    }
+}
+
 #[derive(Clone)]
 struct ContextRecordingTool {
    name: String,
@@ -145,6 +284,7 @@ async fn test_parallel_tool_execution() {
        ],
    ]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let tool1 = SlowTool::new("slow_tool_1", 100);
    let tool2 = SlowTool::new("slow_tool_2", 100);
    let tool3 = SlowTool::new("slow_tool_3", 100);
@@ -159,7 +299,7 @@ async fn test_parallel_tool_execution() {

    let start = Instant::now();
    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let _result = engine.run("Run all tools").await;
+    let _result = engine.run(&mut history, "Run all tools").await;
    let elapsed = start.elapsed();

    // Verify all tools were called
@@ -178,6 +318,450 @@ async fn test_parallel_tool_execution() {
    println!("Parallel execution completed in {:?}", elapsed);
 }

+#[tokio::test]
+async fn completed_results_commit_before_publish_without_waiting_for_siblings() {
+    let client = MockLlmClient::with_responses(vec![
+        vec![
+            Event::tool_use_start(0, "call_slow", "slow_first"),
+            Event::tool_input_delta(0, r#"{}"#),
+            Event::tool_use_stop(0),
+            Event::tool_use_start(1, "call_fast", "fast_second"),
+            Event::tool_input_delta(1, r#"{}"#),
+            Event::tool_use_stop(1),
+            Event::Status(StatusEvent {
+                status: ResponseStatus::Completed,
+            }),
+        ],
+        vec![
+            Event::text_block_start(0),
+            Event::text_delta(0, "Done"),
+            Event::text_block_stop(0, None),
+            Event::Status(StatusEvent {
+                status: ResponseStatus::Completed,
+            }),
+        ],
+    ]);
+    let client_probe = client.clone();
+    let mut engine = Engine::new(client);
+    engine.register_tool(SlowTool::new("slow_first", 100).definition());
+    engine.register_tool(SlowTool::new("fast_second", 5).definition());
+
+    let observed = Arc::new(Mutex::new(Vec::<String>::new()));
+    let published = observed.clone();
+    engine.on_tool_result(move |result| {
+        published
+            .lock()
+            .unwrap()
+            .push(format!("publish:{}", result.tool_use_id));
+    });
+
+    let committed = observed.clone();
+    let mut annotate = move |item: &Item| {
+        if let Item::ToolResult { call_id, .. } = item {
+            committed.lock().unwrap().push(format!("commit:{call_id}"));
+        }
+        Ok(())
+    };
+    let mut history = History::new();
+    let _ = engine
+        .run_with_annotation(&mut history, "run both", &mut annotate)
+        .await;
+    observed.lock().unwrap().push("run-returned".to_string());
+
+    assert_eq!(
+        observed.lock().unwrap().as_slice(),
+        [
+            "commit:call_fast",
+            "publish:call_fast",
+            "commit:call_slow",
+            "publish:call_slow",
+            "run-returned",
+        ]
+    );
+
+    let committed_order: Vec<_> = history
+        .iter()
+        .filter_map(|entry| match &entry.item {
+            Item::ToolResult { call_id, .. } => Some(call_id.as_str()),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(committed_order, ["call_fast", "call_slow"]);
+
+    let requests = client_probe.requests();
+    let projected_order: Vec<_> = requests[1]
+        .items
+        .iter()
+        .filter_map(|item| match item {
+            Item::ToolResult { call_id, .. } => Some(call_id.as_str()),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(projected_order, ["call_slow", "call_fast"]);
+}
+
+#[tokio::test]
+async fn cancellation_preserves_completed_results_and_resume_skips_them() {
+    let client = MockLlmClient::with_responses(vec![
+        vec![
+            Event::tool_use_start(0, "call_hang", "hang_once"),
+            Event::tool_input_delta(0, r#"{}"#),
+            Event::tool_use_stop(0),
+            Event::tool_use_start(1, "call_fast_a", "fast_a"),
+            Event::tool_input_delta(1, r#"{}"#),
+            Event::tool_use_stop(1),
+            Event::tool_use_start(2, "call_fast_b", "fast_b"),
+            Event::tool_input_delta(2, r#"{}"#),
+            Event::tool_use_stop(2),
+            Event::Status(StatusEvent {
+                status: ResponseStatus::Completed,
+            }),
+        ],
+        vec![
+            Event::text_block_start(0),
+            Event::text_delta(0, "Recovered"),
+            Event::text_block_stop(0, None),
+            Event::Status(StatusEvent {
+                status: ResponseStatus::Completed,
+            }),
+        ],
+    ]);
+    let mut engine = Engine::new(client);
+    let hanging = FirstAttemptHangsTool::new();
+    let fast_a = SlowTool::new("fast_a", 1);
+    let fast_b = SlowTool::new("fast_b", 2);
+    engine.register_tool(hanging.definition());
+    engine.register_tool(fast_a.definition());
+    engine.register_tool(fast_b.definition());
+
+    let cancel = engine.cancel_sender();
+    let cancel_task = tokio::spawn(async move {
+        tokio::time::sleep(Duration::from_millis(30)).await;
+        cancel.send(()).await.unwrap();
+    });
+    let mut history = History::new();
+    let output = engine.run(&mut history, "start").await;
+    let mut engine = output.engine;
+    cancel_task.await.unwrap();
+
+    let completed_before_resume = history
+        .iter()
+        .filter(|entry| {
+            matches!(
+                &entry.item,
+                Item::ToolResult { call_id, .. }
+                    if call_id == "call_fast_a" || call_id == "call_fast_b"
+            )
+        })
+        .count();
+    let unknown_before_resume = history
+        .iter()
+        .filter(|entry| {
+            matches!(
+                &entry.item,
+                Item::ToolResult {
+                    call_id,
+                    disposition: ToolResultDisposition::OutcomeUnknown,
+                    ..
+                } if call_id == "call_hang"
+            )
+        })
+        .count();
+    assert_eq!(completed_before_resume, 2);
+    assert_eq!(unknown_before_resume, 1);
+    assert_eq!(fast_a.call_count(), 1);
+    assert_eq!(fast_b.call_count(), 1);
+    assert_eq!(hanging.call_count(), 1);
+
+    let _ = engine.resume(&mut history).await;
+
+    assert_eq!(
+        fast_a.call_count(),
+        1,
+        "completed call must not be re-executed"
+    );
+    assert_eq!(
+        fast_b.call_count(),
+        1,
+        "completed call must not be re-executed"
+    );
+    assert_eq!(
+        hanging.call_count(),
+        1,
+        "OutcomeUnknown is terminal and must not be re-executed"
+    );
+    let completed_after_resume = history
+        .iter()
+        .filter(|entry| {
+            matches!(
+                &entry.item,
+                Item::ToolResult { call_id, .. }
+                    if call_id == "call_fast_a" || call_id == "call_fast_b"
+            )
+        })
+        .count();
+    assert_eq!(completed_after_resume, 2);
+    assert_eq!(
+        history
+            .iter()
+            .filter(|entry| {
+                matches!(
+                    &entry.item,
+                    Item::ToolResult {
+                        call_id,
+                        disposition: ToolResultDisposition::OutcomeUnknown,
+                        ..
+                    } if call_id == "call_hang"
+                )
+            })
+            .count(),
+        1
+    );
+}
+
+#[tokio::test]
+async fn cooperative_cancellation_commits_bounded_terminal_output() {
+    let client = MockLlmClient::with_responses(vec![vec![
+        Event::tool_use_start(0, "call_cooperative", "cooperative"),
+        Event::tool_input_delta(0, r#"{}"#),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]]);
+    let mut engine = Engine::new(client);
+    let tool = CooperativeCancelTool::new();
+    engine.register_tool(tool.definition());
+    let observed = Arc::new(Mutex::new(Vec::<&'static str>::new()));
+    let published = observed.clone();
+    engine.on_tool_result(move |_| published.lock().unwrap().push("published"));
+    let committed = observed.clone();
+    let mut annotate = move |item: &Item| {
+        if matches!(item, Item::ToolResult { .. }) {
+            committed.lock().unwrap().push("committed");
+        }
+        Ok(())
+    };
+
+    let cancel = engine.cancel_sender();
+    let cancel_task = tokio::spawn(async move {
+        tokio::time::sleep(Duration::from_millis(30)).await;
+        cancel.send(()).await.unwrap();
+    });
+    let mut history = History::new();
+    let output = engine
+        .run_with_annotation(&mut history, "start", &mut annotate)
+        .await;
+    observed.lock().unwrap().push("run-returned");
+    cancel_task.await.unwrap();
+
+    assert_eq!(
+        observed.lock().unwrap().as_slice(),
+        ["committed", "published", "run-returned"]
+    );
+    assert_eq!(tool.calls.load(Ordering::SeqCst), 1);
+    let terminal: Vec<_> = history
+        .iter()
+        .filter_map(|entry| match &entry.item {
+            Item::ToolResult {
+                call_id,
+                disposition,
+                content,
+                ..
+            } if call_id == "call_cooperative" => Some((*disposition, content.as_deref())),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(terminal.len(), 1);
+    assert_eq!(terminal[0].0, ToolResultDisposition::Cancelled);
+    assert_eq!(
+        terminal[0].1,
+        Some("stdout before cancellation\nstderr before cancellation")
+    );
+    assert!(matches!(
+        output.result,
+        agen::EngineRunExit::Interrupted(agen::StopReason::Cancelled)
+    ));
+}
+
+#[tokio::test]
+async fn pause_waits_for_started_tool_terminal_without_cancelling_provider() {
+    let client = MockLlmClient::with_responses(vec![vec![
+        Event::tool_use_start(0, "call_safe_pause", "safe_pause"),
+        Event::tool_input_delta(0, r#"{}"#),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]]);
+    let mut engine = Engine::new(client);
+    let tool = SafePauseTool::new();
+    engine.register_tool(tool.definition());
+
+    let pause = engine.pause_sender();
+    let calls = Arc::clone(&tool.calls);
+    let release = Arc::clone(&tool.release);
+    let control = tokio::spawn(async move {
+        tokio::time::timeout(Duration::from_secs(1), async {
+            while calls.load(Ordering::SeqCst) == 0 {
+                tokio::task::yield_now().await;
+            }
+        })
+        .await
+        .expect("tool execution starts");
+        pause.send(()).await.unwrap();
+        tokio::time::sleep(Duration::from_millis(50)).await;
+        release.notify_one();
+    });
+
+    let started_at = std::time::Instant::now();
+    let mut history = History::new();
+    let output = engine.run(&mut history, "pause safely").await;
+    control.await.unwrap();
+
+    assert!(started_at.elapsed() >= Duration::from_millis(50));
+    assert_eq!(tool.calls.load(Ordering::SeqCst), 1);
+    assert_eq!(tool.cancellations.load(Ordering::SeqCst), 0);
+    assert!(matches!(output.result, agen::EngineRunExit::Paused));
+    assert!(history.iter().any(|entry| matches!(
+        &entry.item,
+        Item::ToolResult {
+            call_id,
+            disposition: ToolResultDisposition::Success,
+            ..
+        } if call_id == "call_safe_pause"
+    )));
+}
+
+#[tokio::test]
+async fn pause_escalates_to_explicit_cancel_and_confirm_after_safe_boundary_deadline() {
+    let client = MockLlmClient::with_responses(vec![vec![
+        Event::tool_use_start(0, "call_pause_cancel", "cooperative"),
+        Event::tool_input_delta(0, r#"{}"#),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]]);
+    let mut engine = Engine::new(client);
+    engine.set_tool_execution_policy(ToolExecutionPolicy {
+        pause_safe_boundary_timeout: Duration::from_millis(20),
+        cancellation_request_timeout: Duration::from_millis(50),
+        terminal_confirmation_timeout: Duration::from_millis(100),
+    });
+    let tool = CooperativeCancelTool::new();
+    engine.register_tool(tool.definition());
+
+    let pause = engine.pause_sender();
+    let calls = Arc::clone(&tool.calls);
+    let control = tokio::spawn(async move {
+        tokio::time::timeout(Duration::from_secs(1), async {
+            while calls.load(Ordering::SeqCst) == 0 {
+                tokio::task::yield_now().await;
+            }
+        })
+        .await
+        .expect("tool execution starts");
+        pause.send(()).await.unwrap();
+    });
+
+    let mut history = History::new();
+    let output = engine.run(&mut history, "pause with escalation").await;
+    control.await.unwrap();
+
+    assert!(matches!(output.result, agen::EngineRunExit::Paused));
+    assert!(history.iter().any(|entry| matches!(
+        &entry.item,
+        Item::ToolResult {
+            call_id,
+            disposition: ToolResultDisposition::Cancelled,
+            ..
+        } if call_id == "call_pause_cancel"
+    )));
+}
+
+#[tokio::test]
+async fn cancellation_completion_race_commits_one_terminal_output() {
+    for iteration in 0..24u64 {
+        let client = MockLlmClient::with_responses(vec![
+            vec![
+                Event::tool_use_start(0, "call_racy", "racy"),
+                Event::tool_input_delta(0, r#"{}"#),
+                Event::tool_use_stop(0),
+                Event::Status(StatusEvent {
+                    status: ResponseStatus::Completed,
+                }),
+            ],
+            vec![Event::Status(StatusEvent {
+                status: ResponseStatus::Completed,
+            })],
+        ]);
+        let mut engine = Engine::new(client);
+        let delay = 2 + iteration % 3;
+        let tool = SlowTool::new("racy", delay);
+        engine.register_tool(tool.definition());
+        let cancel = engine.cancel_sender();
+        let cancel_task = tokio::spawn(async move {
+            tokio::time::sleep(Duration::from_millis(delay)).await;
+            let _ = cancel.send(()).await;
+        });
+
+        let mut history = History::new();
+        let _ = engine.run(&mut history, "race").await;
+        cancel_task.await.unwrap();
+        let terminal_count = history
+            .iter()
+            .filter(|entry| {
+                matches!(
+                    &entry.item,
+                    Item::ToolResult { call_id, .. } if call_id == "call_racy"
+                )
+            })
+            .count();
+        assert_eq!(terminal_count, 1, "iteration {iteration}");
+        assert_eq!(tool.call_count(), 1, "iteration {iteration}");
+    }
+}
+
+#[tokio::test]
+async fn tool_result_commit_failure_prevents_publication() {
+    let client = MockLlmClient::with_responses(vec![vec![
+        Event::tool_use_start(0, "call_fast", "fast"),
+        Event::tool_input_delta(0, r#"{}"#),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]]);
+    let mut engine = Engine::new(client);
+    engine.register_tool(SlowTool::new("fast", 1).definition());
+
+    let published = Arc::new(AtomicUsize::new(0));
+    let published_probe = published.clone();
+    engine.on_tool_result(move |_| {
+        published_probe.fetch_add(1, Ordering::SeqCst);
+    });
+
+    let mut history = History::new();
+    let mut reject_tool_result = |item: &Item| {
+        if matches!(item, Item::ToolResult { .. }) {
+            Err("session log unavailable".to_string())
+        } else {
+            Ok(())
+        }
+    };
+    let _ = engine
+        .run_with_annotation(&mut history, "start", &mut reject_tool_result)
+        .await;
+
+    assert_eq!(published.load(Ordering::SeqCst), 0);
+    assert!(
+        history
+            .iter()
+            .all(|entry| !matches!(entry.item, Item::ToolResult { .. }))
+    );
+}
+
 #[tokio::test]
 async fn test_tool_execution_context_order_and_batch_id() {
    let client = MockLlmClient::with_responses(vec![
@@ -205,13 +789,14 @@ async fn test_tool_execution_context_order_and_batch_id() {
        ],
    ]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let contexts = Arc::new(Mutex::new(Vec::new()));

    engine.register_tool(ContextRecordingTool::new("record_a", contexts.clone()).definition());
    engine.register_tool(ContextRecordingTool::new("record_b", contexts.clone()).definition());
    engine.register_tool(ContextRecordingTool::new("record_c", contexts.clone()).definition());

-    let _ = engine.run("record contexts").await;
+    let _ = engine.run(&mut history, "record contexts").await;

    let mut contexts = contexts.lock().unwrap().clone();
    contexts.sort_by_key(|ctx| ctx.call_index);
@@ -256,11 +841,12 @@ async fn test_tool_execution_context_batch_id_changes_between_batches() {
        ],
    ]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let contexts = Arc::new(Mutex::new(Vec::new()));

    engine.register_tool(ContextRecordingTool::new("record", contexts.clone()).definition());

-    let _ = engine.run("record batches").await;
+    let _ = engine.run(&mut history, "record batches").await;

    let contexts = contexts.lock().unwrap().clone();
    assert_eq!(contexts.len(), 2);
@@ -298,6 +884,7 @@ async fn test_tool_execution_context_for_skipped_and_synthetic_paths() {
        ],
    ]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let executed_contexts = Arc::new(Mutex::new(Vec::new()));
    let pre_contexts = Arc::new(Mutex::new(Vec::new()));
    let post_contexts = Arc::new(Mutex::new(Vec::new()));
@@ -344,7 +931,9 @@ async fn test_tool_execution_context_for_skipped_and_synthetic_paths() {
        post_contexts: post_contexts.clone(),
    });

-    let _ = engine.run("record skipped and synthetic contexts").await;
+    let _ = engine
+        .run(&mut history, "record skipped and synthetic contexts")
+        .await;

    let mut pre_contexts = pre_contexts.lock().unwrap().clone();
    pre_contexts.sort_by_key(|ctx| ctx.call_index);
@@ -389,6 +978,7 @@ async fn test_before_tool_call_skip() {

    let client = MockLlmClient::new(events);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    let allowed_tool = SlowTool::new("allowed_tool", 10);
    let blocked_tool = SlowTool::new("blocked_tool", 10);
@@ -416,7 +1006,7 @@ async fn test_before_tool_call_skip() {
    engine.set_interceptor(BlockingPolicy);

    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let _result = engine.run("Test hook").await;
+    let _result = engine.run(&mut history, "Test hook").await;

    // allowed_tool is called, but blocked_tool is not
    assert_eq!(
@@ -457,6 +1047,7 @@ async fn test_post_tool_call_modification() {
    ]);

    let mut engine = Engine::new(client);
+    let mut history: History = History::new();

    #[derive(Clone)]
    struct SimpleTool;
@@ -503,9 +1094,12 @@ async fn test_post_tool_call_modification() {
    });

    // Mutable::run consumes self, returns (Locked, EngineResult)
-    let result = engine.run("Test modification").await;
+    let result = engine.run(&mut history, "Test modification").await;

-    assert!(result.is_ok(), "Engine should complete");
+    assert!(
+        matches!(result.result, agen::EngineRunExit::Finished),
+        "Engine should complete"
+    );

    // Verify hook was called and content was modified
    let content = modified_content.lock().unwrap().clone();
@@ -540,6 +1134,7 @@ async fn test_before_tool_call_synthetic_result_committed() {
        ],
    ]);
    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    let blocked_tool = SlowTool::new("blocked_tool", 10);
    let blocked_clone = blocked_tool.clone();
    engine.register_tool(blocked_tool.definition());
@@ -558,10 +1153,10 @@ async fn test_before_tool_call_synthetic_result_committed() {

    engine.set_interceptor(SyntheticPolicy);

-    let result = engine.run("Test synthetic result").await.unwrap();
+    let _result = engine.run(&mut history, "Test synthetic result").await;

    assert_eq!(blocked_clone.call_count(), 0, "Blocked tool should not run");
-    assert!(result.engine.history().iter().any(|item| matches!(
+    assert!(history.items().any(|item| matches!(
        item,
        agen::Item::ToolResult {
            call_id,
@@ -571,3 +1166,76 @@ async fn test_before_tool_call_synthetic_result_committed() {
        } if call_id == "call_1" && summary == "permission denied"
    )));
 }
+
+#[tokio::test]
+async fn post_tool_abort_commits_confirmed_result_before_stopping_run() {
+    let client = MockLlmClient::new(vec![
+        Event::tool_use_start(0, "call_confirmed", "confirmed"),
+        Event::tool_input_delta(0, r#"{}"#),
+        Event::tool_use_stop(0),
+        Event::Status(StatusEvent {
+            status: ResponseStatus::Completed,
+        }),
+    ]);
+    let mut engine = Engine::new(client);
+    let tool = SlowTool::new("confirmed", 1);
+    engine.register_tool(tool.definition());
+
+    struct AbortAfterResult;
+    #[async_trait]
+    impl Interceptor for AbortAfterResult {
+        async fn post_tool_call(&self, _info: &mut ToolResultInfo) -> PostToolAction {
+            PostToolAction::Abort("policy stopped the run".to_string())
+        }
+    }
+    engine.set_interceptor(AbortAfterResult);
+
+    let observed = Arc::new(Mutex::new(Vec::<&'static str>::new()));
+    let published = observed.clone();
+    engine.on_tool_result(move |_| published.lock().unwrap().push("published"));
+    let committed = observed.clone();
+    let mut annotate = move |item: &Item| {
+        if matches!(item, Item::ToolResult { .. }) {
+            committed.lock().unwrap().push("committed");
+        }
+        Ok(())
+    };
+
+    let mut history = History::new();
+    let output = engine
+        .run_with_annotation(&mut history, "run confirmed tool", &mut annotate)
+        .await;
+    observed.lock().unwrap().push("run-returned");
+
+    assert_eq!(tool.call_count(), 1);
+    assert_eq!(
+        observed.lock().unwrap().as_slice(),
+        ["committed", "published", "run-returned"]
+    );
+    assert!(matches!(
+        output.result,
+        agen::EngineRunExit::Interrupted(agen::StopReason::Unexpected(
+            agen::EngineError::Aborted(ref reason)
+        )) if reason == "policy stopped the run"
+    ));
+    let terminal: Vec<_> = history
+        .iter()
+        .filter_map(|entry| match &entry.item {
+            Item::ToolResult {
+                call_id,
+                disposition,
+                ..
+            } if call_id == "call_confirmed" => Some(*disposition),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(terminal, [ToolResultDisposition::Success]);
+    assert!(!history.iter().any(|entry| matches!(
+        &entry.item,
+        Item::ToolResult {
+            call_id,
+            disposition: ToolResultDisposition::OutcomeUnknown,
+            ..
+        } if call_id == "call_confirmed"
+    )));
+}
@@ -13,12 +13,12 @@

 mod common;

-use agen::Engine;
 use agen::Item;
 use agen::llm_client::event::{
    BlockMetadata, BlockStart, BlockStop, BlockType, Event, ReasoningBlockData, ResponseStatus,
    StatusEvent,
 };
+use agen::{Engine, History};
 use common::MockLlmClient;

 fn reasoning_block(text: impl Into<String>, data: ReasoningBlockData) -> Vec<Event> {
@@ -65,15 +65,15 @@ async fn anthropic_thinking_round_trips_signature_into_history() {
    ]);
    let client = MockLlmClient::new(events);
    let engine = Engine::new(client);
-    let out = engine.run("question?").await.expect("run ok");
-    let engine = out.engine;
+    let mut history: History = History::new();
+    let _out = engine.run(&mut history, "question?").await;

-    let history = engine.history();
+    let entries = history.entries();
    // user / reasoning / assistant_message
    assert_eq!(history.len(), 3, "history: {history:?}");

-    assert!(matches!(history[0], Item::Message { .. }));
-    match &history[1] {
+    assert!(matches!(entries[0].item, Item::Message { .. }));
+    match &entries[1].item {
        Item::Reasoning {
            text, signature, ..
        } => {
@@ -82,7 +82,7 @@ async fn anthropic_thinking_round_trips_signature_into_history() {
        }
        other => panic!("expected Reasoning, got {other:?}"),
    }
-    assert_eq!(history[2].as_text(), Some("Here's the answer"));
+    assert_eq!(entries[2].item.as_text(), Some("Here's the answer"));
 }

 /// OpenAI Responses 風: encrypted_content + summary を持った reasoning が
@@ -109,11 +109,11 @@ async fn openai_reasoning_round_trips_encrypted_and_summary() {
    ]);
    let client = MockLlmClient::new(events);
    let engine = Engine::new(client);
-    let out = engine.run("q").await.expect("run ok");
-    let engine = out.engine;
+    let mut history: History = History::new();
+    let _out = engine.run(&mut history, "q").await;

-    let history = engine.history();
-    match &history[1] {
+    let entries = history.entries();
+    match &entries[1].item {
        Item::Reasoning {
            text,
            summary,
@@ -155,13 +155,13 @@ async fn reasoning_precedes_text_in_assistant_burst() {
    }));
    let client = MockLlmClient::new(events);
    let engine = Engine::new(client);
-    let out = engine.run("q").await.expect("run ok");
-    let engine = out.engine;
+    let mut history: History = History::new();
+    let _out = engine.run(&mut history, "q").await;

-    let history = engine.history();
+    let entries = history.entries();
    // user / reasoning(先頭) / assistant_message
-    assert!(matches!(history[1], Item::Reasoning { .. }));
-    assert_eq!(history[2].as_text(), Some("intermediate"));
+    assert!(matches!(entries[1].item, Item::Reasoning { .. }));
+    assert_eq!(entries[2].item.as_text(), Some("intermediate"));
 }

 /// resume シナリオ: history.json 由来の Item::Reasoning(signature) を Engine に
@@ -207,14 +207,18 @@ async fn injected_reasoning_survives_into_outgoing_request() {
    };

    let mut engine = Engine::new(client);
+    let mut history: History = History::new();
    // resume: 既存 history を流し込む
-    engine.set_history(vec![
+    engine.set_history(
+        &mut history,
+        vec![
            Item::user_message("prior question"),
            Item::reasoning("prior thinking").with_signature("SIG-PRIOR"),
            Item::assistant_message("prior answer"),
-    ]);
+        ],
+    );

-    let _ = engine.run("follow up").await.expect("run ok");
+    let _ = engine.run(&mut history, "follow up").await;

    let req = captured
        .lock()
@@ -1,4 +1,4 @@
-use agen::Engine;
+use agen::{Engine, History};
 use agen::llm_client::capability::{
    CacheStrategy, ModelCapability, StructuredOutput, ToolCallingSupport,
 };
@@ -22,7 +22,8 @@ fn main() {
        cap,
    );
    let engine = Engine::new(client);
-    let mut locked = engine.lock();
+    let history = History::new();
+    let mut locked = engine.lock(&history);
    let def: agen::tool::ToolDefinition = Arc::new(|| panic!("unused"));
    let _ = locked.register_tool(def);
 }
@@ -1,8 +1,8 @@
 error[E0599]: no method named `register_tool` found for struct `Engine<HttpTransport<AnthropicScheme>, Locked>` in the current scope
-  --> tests/ui/locked_register_tool.rs:27:20
+  --> tests/ui/locked_register_tool.rs:28:20
   |
-27 |     let _ = locked.register_tool(def);
+28 |     let _ = locked.register_tool(def);
   |                    ^^^^^^^^^^^^^ method not found in `Engine<HttpTransport<AnthropicScheme>, Locked>`
   |
   = note: the method was found for
-           - `Engine<C>`
+           - `Engine<C, Mutable, A>`
@@ -5,19 +5,19 @@ edition.workspace = true
 license.workspace = true

 [dependencies]
+async-trait.workspace = true
+chrono = { version = "0.4", default-features = false, features = ["clock"] }
 protocol = { workspace = true }
-manifest = { workspace = true }
 ticket = { workspace = true }
 futures = { workspace = true }
 reqwest = { version = "0.13", default-features = false, features = ["blocking", "json", "native-tls"] }
 serde = { workspace = true }
 serde_json = { workspace = true }
 thiserror = { workspace = true }
-tokio = { workspace = true, features = ["rt", "macros", "net", "io-util", "sync", "time", "process", "fs"] }
+tokio = { workspace = true, features = ["rt", "macros", "net", "io-util", "sync", "time"] }
 tokio-tungstenite = { workspace = true }
 uuid = { workspace = true }
 workspace-api.workspace = true
-workdir = { workspace = true }

 [dev-dependencies]
 tempfile = { workspace = true }
@@ -0,0 +1,839 @@
+use chrono::{DateTime, Utc};
+use reqwest::{Method, StatusCode, Url, redirect};
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeMap;
+use std::env;
+use std::fmt;
+use std::fs::{self, OpenOptions};
+use std::io::Write as _;
+use std::path::{Path, PathBuf};
+
+const TOKEN_FILE_NAME: &str = "backend-tokens.json";
+const MAX_REDIRECTS: usize = 10;
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct BackendOrigin(String);
+
+impl BackendOrigin {
+    pub fn parse(input: &str) -> Result<Self, BackendApiClientError> {
+        let url = Url::parse(input.trim()).map_err(|error| {
+            BackendApiClientError::InvalidBackendOrigin(format!(
+                "Backend URL is not a valid absolute URL: {error}"
+            ))
+        })?;
+        if !url.path().bytes().all(|byte| byte == b'/')
+            || url.query().is_some()
+            || url.fragment().is_some()
+        {
+            return Err(BackendApiClientError::InvalidBackendOrigin(
+                "Backend URL must contain only an origin, without a path, query, or fragment"
+                    .to_string(),
+            ));
+        }
+        Self::from_url(url)
+    }
+
+    fn from_url(mut url: Url) -> Result<Self, BackendApiClientError> {
+        if !matches!(url.scheme(), "http" | "https") {
+            return Err(BackendApiClientError::InvalidBackendOrigin(
+                "Backend URL scheme must be http or https".to_string(),
+            ));
+        }
+        if !url.username().is_empty() || url.password().is_some() {
+            return Err(BackendApiClientError::InvalidBackendOrigin(
+                "Backend URL must not contain user information".to_string(),
+            ));
+        }
+        if url.host().is_none() {
+            return Err(BackendApiClientError::InvalidBackendOrigin(
+                "Backend URL must contain a host".to_string(),
+            ));
+        }
+        let default_port = match url.scheme() {
+            "http" => 80,
+            "https" => 443,
+            _ => unreachable!("validated Backend URL scheme"),
+        };
+        if url.port() == Some(default_port) {
+            url.set_port(None).map_err(|()| {
+                BackendApiClientError::InvalidBackendOrigin(
+                    "Backend URL contains an invalid port".to_string(),
+                )
+            })?;
+        }
+        url.set_path("");
+        url.set_query(None);
+        url.set_fragment(None);
+        let normalized = url.as_str().trim_end_matches('/').to_string();
+        Ok(Self(normalized))
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+
+    fn url(&self, path_and_query: &str) -> Result<Url, BackendApiClientError> {
+        if !path_and_query.starts_with('/') || path_and_query.starts_with("//") {
+            return Err(BackendApiClientError::InvalidRequestPath(
+                "Backend API request path must start with one `/`".to_string(),
+            ));
+        }
+        Url::parse(&format!("{}{path_and_query}", self.0)).map_err(|error| {
+            BackendApiClientError::InvalidRequestPath(format!(
+                "Backend API request path is invalid: {error}"
+            ))
+        })
+    }
+}
+
+impl fmt::Debug for BackendOrigin {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("BackendOrigin").field(&self.0).finish()
+    }
+}
+
+impl fmt::Display for BackendOrigin {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+#[derive(Clone)]
+struct BackendAccessToken(String);
+
+impl fmt::Debug for BackendAccessToken {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("BackendAccessToken([REDACTED])")
+    }
+}
+
+#[derive(Clone)]
+pub struct BackendApiClient {
+    origin: BackendOrigin,
+    access_token: BackendAccessToken,
+    asynchronous: reqwest::Client,
+}
+
+impl fmt::Debug for BackendApiClient {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BackendApiClient")
+            .field("origin", &self.origin)
+            .field("access_token", &self.access_token)
+            .finish_non_exhaustive()
+    }
+}
+
+impl BackendApiClient {
+    pub fn from_stored_token(base_url: &str) -> Result<Self, BackendApiClientError> {
+        let path = backend_token_file_path()?;
+        Self::from_token_file(base_url, &path)
+    }
+
+    fn from_token_file(base_url: &str, path: &Path) -> Result<Self, BackendApiClientError> {
+        let origin = BackendOrigin::parse(base_url)?;
+        let token_file = read_token_file(path)?;
+        let entry = token_file.tokens.get(origin.as_str()).ok_or_else(|| {
+            BackendApiClientError::TokenEntryMissing {
+                origin: origin.clone(),
+                path: path.to_path_buf(),
+            }
+        })?;
+        validate_token_entry(entry, &origin, path)?;
+        Self::new(origin, BackendAccessToken(entry.access_token.clone()))
+    }
+
+    fn new(
+        origin: BackendOrigin,
+        access_token: BackendAccessToken,
+    ) -> Result<Self, BackendApiClientError> {
+        let asynchronous = reqwest::Client::builder()
+            .redirect(redirect_policy(origin.clone()))
+            .build()
+            .map_err(BackendApiClientError::Http)?;
+        Ok(Self {
+            origin,
+            access_token,
+            asynchronous,
+        })
+    }
+
+    pub fn origin(&self) -> &BackendOrigin {
+        &self.origin
+    }
+
+    pub fn request(
+        &self,
+        method: Method,
+        path_and_query: &str,
+    ) -> Result<reqwest::RequestBuilder, BackendApiClientError> {
+        let url = self.origin.url(path_and_query)?;
+        Ok(self
+            .asynchronous
+            .request(method, url)
+            .bearer_auth(&self.access_token.0))
+    }
+
+    pub fn blocking_request(
+        &self,
+        method: Method,
+        path_and_query: &str,
+    ) -> Result<reqwest::blocking::RequestBuilder, BackendApiClientError> {
+        let url = self.origin.url(path_and_query)?;
+        let client = reqwest::blocking::Client::builder()
+            .redirect(redirect_policy(self.origin.clone()))
+            .build()
+            .map_err(BackendApiClientError::Http)?;
+        Ok(client
+            .request(method, url)
+            .bearer_auth(&self.access_token.0))
+    }
+
+    pub(crate) fn authorization_header_value(&self) -> String {
+        format!("Bearer {}", self.access_token.0)
+    }
+
+    pub async fn require_success(
+        &self,
+        response: reqwest::Response,
+    ) -> Result<reqwest::Response, BackendApiClientError> {
+        let status = response.status();
+        match status {
+            StatusCode::UNAUTHORIZED | StatusCode::FORBIDDEN => {
+                self.check_status(status)?;
+            }
+            status if !status.is_success() => {
+                let detail = response
+                    .bytes()
+                    .await
+                    .ok()
+                    .and_then(|body| backend_error_detail(&body));
+                return Err(BackendApiClientError::BackendResponse {
+                    origin: self.origin.clone(),
+                    status: status.as_u16(),
+                    detail,
+                });
+            }
+            _ => {}
+        }
+        Ok(response)
+    }
+
+    pub fn check_status(&self, status: StatusCode) -> Result<(), BackendApiClientError> {
+        match status {
+            StatusCode::UNAUTHORIZED => Err(BackendApiClientError::Unauthorized {
+                origin: self.origin.clone(),
+            }),
+            StatusCode::FORBIDDEN => Err(BackendApiClientError::Forbidden {
+                origin: self.origin.clone(),
+            }),
+            status if !status.is_success() => Err(BackendApiClientError::BackendStatus {
+                origin: self.origin.clone(),
+                status: status.as_u16(),
+            }),
+            _ => Ok(()),
+        }
+    }
+
+    #[cfg(test)]
+    pub(crate) fn from_access_token_for_test(
+        base_url: &str,
+        access_token: &str,
+    ) -> Result<Self, BackendApiClientError> {
+        Self::new(
+            BackendOrigin::parse(base_url)?,
+            BackendAccessToken(access_token.to_string()),
+        )
+    }
+}
+
+fn redirect_policy(origin: BackendOrigin) -> redirect::Policy {
+    redirect::Policy::custom(move |attempt| {
+        if attempt.previous().len() >= MAX_REDIRECTS {
+            return attempt.error("Backend request exceeded the redirect limit");
+        }
+        match BackendOrigin::from_url(attempt.url().clone()) {
+            Ok(target_origin) if target_origin == origin => attempt.follow(),
+            Ok(target_origin) => attempt.error(format!(
+                "Backend request refused a cross-origin redirect from {origin} to {target_origin}"
+            )),
+            Err(error) => attempt.error(error.to_string()),
+        }
+    })
+}
+
+#[derive(Deserialize)]
+struct BackendErrorBody {
+    message: String,
+}
+
+fn backend_error_detail(body: &[u8]) -> Option<String> {
+    serde_json::from_slice::<BackendErrorBody>(body)
+        .ok()
+        .map(|body| body.message)
+        .filter(|message| !message.trim().is_empty())
+}
+
+#[derive(Debug)]
+pub enum BackendApiClientError {
+    InvalidBackendOrigin(String),
+    InvalidRequestPath(String),
+    ConfigDirectoryUnavailable,
+    TokenFileMissing {
+        path: PathBuf,
+    },
+    TokenFileMalformed {
+        path: PathBuf,
+        message: String,
+    },
+    TokenEntryMissing {
+        origin: BackendOrigin,
+        path: PathBuf,
+    },
+    TokenExpired {
+        origin: BackendOrigin,
+        expired_at: String,
+    },
+    Http(reqwest::Error),
+    Unauthorized {
+        origin: BackendOrigin,
+    },
+    Forbidden {
+        origin: BackendOrigin,
+    },
+    BackendStatus {
+        origin: BackendOrigin,
+        status: u16,
+    },
+    BackendResponse {
+        origin: BackendOrigin,
+        status: u16,
+        detail: Option<String>,
+    },
+    Io {
+        path: PathBuf,
+        source: std::io::Error,
+    },
+}
+
+impl fmt::Display for BackendApiClientError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::InvalidBackendOrigin(message) | Self::InvalidRequestPath(message) => {
+                f.write_str(message)
+            }
+            Self::ConfigDirectoryUnavailable => f.write_str(
+                "cannot locate the client configuration directory for backend-tokens.json",
+            ),
+            Self::TokenFileMissing { path } => write!(
+                f,
+                "Backend token file {} is missing; run `yoi login --backend <BACKEND>` first",
+                path.display()
+            ),
+            Self::TokenFileMalformed { path, message } => write!(
+                f,
+                "Backend token file {} is malformed: {message}; run `yoi login --backend <BACKEND>` again",
+                path.display()
+            ),
+            Self::TokenEntryMissing { origin, path } => write!(
+                f,
+                "no Backend token for {origin} exists in {}; login URLs are matched by normalized origin, so run `yoi login --backend {origin}`",
+                path.display()
+            ),
+            Self::TokenExpired { origin, expired_at } => write!(
+                f,
+                "Backend token for {origin} expired at {expired_at}; run `yoi login --backend {origin}` again"
+            ),
+            Self::Http(error) => write!(f, "Backend request failed: {error}"),
+            Self::Unauthorized { origin } => write!(
+                f,
+                "Backend {origin} returned HTTP 401 for the saved token; it may be expired or revoked, so run `yoi login --backend {origin}` again"
+            ),
+            Self::Forbidden { origin } => write!(
+                f,
+                "Backend {origin} returned HTTP 403; the saved token is authenticated but is not authorized for this operation"
+            ),
+            Self::BackendStatus { origin, status } => {
+                write!(f, "Backend {origin} returned HTTP {status}")
+            }
+            Self::BackendResponse {
+                origin,
+                status,
+                detail,
+            } => {
+                write!(f, "Backend {origin} returned HTTP {status}")?;
+                if let Some(detail) = detail {
+                    write!(f, ": {detail}")?;
+                }
+                Ok(())
+            }
+            Self::Io { path, source } => {
+                write!(f, "failed to access {}: {source}", path.display())
+            }
+        }
+    }
+}
+
+impl std::error::Error for BackendApiClientError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            Self::Http(error) => Some(error),
+            Self::Io { source, .. } => Some(source),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+struct BackendTokenFile {
+    tokens: BTreeMap<String, BackendTokenEntry>,
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+struct BackendTokenEntry {
+    token_type: String,
+    access_token: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    expires_at: Option<String>,
+}
+
+pub fn save_backend_token(
+    base_url: &str,
+    token_type: &str,
+    access_token: &str,
+) -> Result<PathBuf, BackendApiClientError> {
+    save_backend_token_with_expiry(base_url, token_type, access_token, None)
+}
+
+fn save_backend_token_with_expiry(
+    base_url: &str,
+    token_type: &str,
+    access_token: &str,
+    expires_at: Option<String>,
+) -> Result<PathBuf, BackendApiClientError> {
+    let path = backend_token_file_path()?;
+    save_backend_token_to_file(base_url, token_type, access_token, expires_at, &path)?;
+    Ok(path)
+}
+
+fn save_backend_token_to_file(
+    base_url: &str,
+    token_type: &str,
+    access_token: &str,
+    expires_at: Option<String>,
+    path: &Path,
+) -> Result<(), BackendApiClientError> {
+    let origin = BackendOrigin::parse(base_url)?;
+    let mut token_file = if path.exists() {
+        read_token_file(&path)?
+    } else {
+        BackendTokenFile {
+            tokens: BTreeMap::new(),
+        }
+    };
+    let entry = BackendTokenEntry {
+        token_type: token_type.to_string(),
+        access_token: access_token.to_string(),
+        expires_at,
+    };
+    validate_token_entry(&entry, &origin, path)?;
+    token_file.tokens.insert(origin.to_string(), entry);
+    write_token_file(path, &token_file)?;
+    Ok(())
+}
+
+pub fn backend_token_file_path() -> Result<PathBuf, BackendApiClientError> {
+    if let Some(config_home) = env::var_os("XDG_CONFIG_HOME") {
+        return Ok(PathBuf::from(config_home).join("yoi").join(TOKEN_FILE_NAME));
+    }
+    let Some(home) = env::var_os("HOME") else {
+        return Err(BackendApiClientError::ConfigDirectoryUnavailable);
+    };
+    Ok(PathBuf::from(home)
+        .join(".config")
+        .join("yoi")
+        .join(TOKEN_FILE_NAME))
+}
+
+fn read_token_file(path: &Path) -> Result<BackendTokenFile, BackendApiClientError> {
+    let bytes = fs::read(path).map_err(|source| {
+        if source.kind() == std::io::ErrorKind::NotFound {
+            BackendApiClientError::TokenFileMissing {
+                path: path.to_path_buf(),
+            }
+        } else {
+            BackendApiClientError::Io {
+                path: path.to_path_buf(),
+                source,
+            }
+        }
+    })?;
+    let raw: BackendTokenFile = serde_json::from_slice(&bytes).map_err(|error| {
+        BackendApiClientError::TokenFileMalformed {
+            path: path.to_path_buf(),
+            message: error.to_string(),
+        }
+    })?;
+    normalize_token_file(raw, path)
+}
+
+fn normalize_token_file(
+    token_file: BackendTokenFile,
+    path: &Path,
+) -> Result<BackendTokenFile, BackendApiClientError> {
+    let mut normalized = BTreeMap::new();
+    for (raw_origin, entry) in token_file.tokens {
+        let origin = BackendOrigin::parse(&raw_origin).map_err(|error| {
+            BackendApiClientError::TokenFileMalformed {
+                path: path.to_path_buf(),
+                message: format!("token key `{raw_origin}` is invalid: {error}"),
+            }
+        })?;
+        if normalized.insert(origin.to_string(), entry).is_some() {
+            return Err(BackendApiClientError::TokenFileMalformed {
+                path: path.to_path_buf(),
+                message: format!("more than one token entry normalizes to `{origin}`"),
+            });
+        }
+    }
+    Ok(BackendTokenFile { tokens: normalized })
+}
+
+fn validate_token_entry(
+    entry: &BackendTokenEntry,
+    origin: &BackendOrigin,
+    path: &Path,
+) -> Result<(), BackendApiClientError> {
+    if !entry.token_type.eq_ignore_ascii_case("Bearer") {
+        return Err(BackendApiClientError::TokenFileMalformed {
+            path: path.to_path_buf(),
+            message: format!("token for `{origin}` does not use the Bearer token type"),
+        });
+    }
+    if entry.access_token.trim().is_empty()
+        || entry.access_token.contains('\r')
+        || entry.access_token.contains('\n')
+    {
+        return Err(BackendApiClientError::TokenFileMalformed {
+            path: path.to_path_buf(),
+            message: format!("token for `{origin}` is empty or contains an invalid line break"),
+        });
+    }
+    if reqwest::header::HeaderValue::from_str(&format!("Bearer {}", entry.access_token)).is_err() {
+        return Err(BackendApiClientError::TokenFileMalformed {
+            path: path.to_path_buf(),
+            message: format!("token for `{origin}` cannot be represented as an HTTP header"),
+        });
+    }
+    if let Some(expires_at) = entry.expires_at.as_deref() {
+        let expiration = DateTime::parse_from_rfc3339(expires_at).map_err(|error| {
+            BackendApiClientError::TokenFileMalformed {
+                path: path.to_path_buf(),
+                message: format!("token for `{origin}` has invalid expires_at: {error}"),
+            }
+        })?;
+        if expiration <= Utc::now() {
+            return Err(BackendApiClientError::TokenExpired {
+                origin: origin.clone(),
+                expired_at: expires_at.to_string(),
+            });
+        }
+    }
+    Ok(())
+}
+
+fn write_token_file(
+    path: &Path,
+    token_file: &BackendTokenFile,
+) -> Result<(), BackendApiClientError> {
+    let parent = path
+        .parent()
+        .ok_or(BackendApiClientError::ConfigDirectoryUnavailable)?;
+    fs::create_dir_all(parent).map_err(|source| BackendApiClientError::Io {
+        path: parent.to_path_buf(),
+        source,
+    })?;
+    let payload = serde_json::to_vec_pretty(token_file).map_err(|error| {
+        BackendApiClientError::TokenFileMalformed {
+            path: path.to_path_buf(),
+            message: error.to_string(),
+        }
+    })?;
+    let temp_path = parent.join(format!(".{TOKEN_FILE_NAME}.tmp-{}", std::process::id()));
+    let mut options = OpenOptions::new();
+    options.write(true).create(true).truncate(true);
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::OpenOptionsExt;
+        options.mode(0o600);
+    }
+    let mut file = options
+        .open(&temp_path)
+        .map_err(|source| BackendApiClientError::Io {
+            path: temp_path.clone(),
+            source,
+        })?;
+    file.write_all(&payload)
+        .and_then(|()| file.write_all(b"\n"))
+        .and_then(|()| file.sync_all())
+        .map_err(|source| BackendApiClientError::Io {
+            path: temp_path.clone(),
+            source,
+        })?;
+    fs::rename(&temp_path, path).map_err(|source| BackendApiClientError::Io {
+        path: path.to_path_buf(),
+        source,
+    })?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::{Read, Write};
+    use std::net::TcpListener;
+    use std::thread;
+    use std::time::{Duration, SystemTime, UNIX_EPOCH};
+
+    fn temp_path(label: &str) -> PathBuf {
+        let nonce = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        env::temp_dir().join(format!(
+            "yoi-client-{label}-{}-{nonce}.json",
+            std::process::id()
+        ))
+    }
+
+    fn write_fixture(path: &Path, value: serde_json::Value) {
+        fs::write(path, serde_json::to_vec(&value).unwrap()).unwrap();
+    }
+
+    #[test]
+    fn backend_origin_normalizes_safe_equivalents() {
+        let variants = [
+            "HTTP://Example.COM",
+            "http://example.com/",
+            "http://example.com:80////",
+        ];
+        for variant in variants {
+            assert_eq!(
+                BackendOrigin::parse(variant).unwrap().as_str(),
+                "http://example.com"
+            );
+        }
+        assert_eq!(
+            BackendOrigin::parse("https://EXAMPLE.com:443/")
+                .unwrap()
+                .as_str(),
+            "https://example.com"
+        );
+        assert_eq!(
+            BackendOrigin::parse("https://example.com:8443/")
+                .unwrap()
+                .as_str(),
+            "https://example.com:8443"
+        );
+    }
+
+    #[test]
+    fn backend_error_detail_preserves_public_server_message() {
+        let detail = backend_error_detail(
+            br#"{"error":"Bad Request","message":"working_directory_runtime_mismatch: Working directory is owned by a different Runtime","diagnostics":[{"code":"working_directory_runtime_mismatch"}]}"#,
+        );
+        let error = BackendApiClientError::BackendResponse {
+            origin: BackendOrigin::parse("http://127.0.0.1:8787").unwrap(),
+            status: 400,
+            detail,
+        };
+
+        assert_eq!(
+            error.to_string(),
+            "Backend http://127.0.0.1:8787 returned HTTP 400: working_directory_runtime_mismatch: Working directory is owned by a different Runtime"
+        );
+    }
+
+    #[test]
+    fn backend_origin_rejects_unsafe_authority_changes() {
+        for invalid in [
+            "ftp://example.com",
+            "https://user@example.com",
+            "https://example.com/api",
+            "https://example.com/?query=1",
+            "https://example.com/#fragment",
+        ] {
+            assert!(BackendOrigin::parse(invalid).is_err(), "accepted {invalid}");
+        }
+        assert_ne!(
+            BackendOrigin::parse("http://localhost:8787").unwrap(),
+            BackendOrigin::parse("http://127.0.0.1:8787").unwrap()
+        );
+    }
+
+    #[test]
+    fn token_lookup_distinguishes_missing_malformed_mismatch_and_expired() {
+        let missing = temp_path("missing");
+        assert!(matches!(
+            BackendApiClient::from_token_file("http://localhost:8787", &missing),
+            Err(BackendApiClientError::TokenFileMissing { .. })
+        ));
+
+        let malformed = temp_path("malformed");
+        fs::write(&malformed, b"not json").unwrap();
+        assert!(matches!(
+            BackendApiClient::from_token_file("http://localhost:8787", &malformed),
+            Err(BackendApiClientError::TokenFileMalformed { .. })
+        ));
+
+        let mismatch = temp_path("mismatch");
+        write_fixture(
+            &mismatch,
+            serde_json::json!({"tokens": {"http://localhost:8787": {
+                "token_type": "Bearer", "access_token": "secret"
+            }}}),
+        );
+        assert!(matches!(
+            BackendApiClient::from_token_file("http://127.0.0.1:8787", &mismatch),
+            Err(BackendApiClientError::TokenEntryMissing { .. })
+        ));
+
+        let expired = temp_path("expired");
+        write_fixture(
+            &expired,
+            serde_json::json!({"tokens": {"http://localhost:8787": {
+                "token_type": "Bearer",
+                "access_token": "secret",
+                "expires_at": "2000-01-01T00:00:00Z"
+            }}}),
+        );
+        assert!(matches!(
+            BackendApiClient::from_token_file("http://localhost:8787", &expired),
+            Err(BackendApiClientError::TokenExpired { .. })
+        ));
+
+        for path in [malformed, mismatch, expired] {
+            let _ = fs::remove_file(path);
+        }
+    }
+
+    #[test]
+    fn token_write_and_lookup_share_origin_normalization() {
+        let path = temp_path("normalized-write");
+        save_backend_token_to_file(
+            "HTTP://Example.COM:80////",
+            "Bearer",
+            "normalized-secret",
+            None,
+            &path,
+        )
+        .unwrap();
+        let contents = fs::read_to_string(&path).unwrap();
+        assert!(contents.contains("\"http://example.com\""));
+        let client = BackendApiClient::from_token_file("http://example.com/", &path).unwrap();
+        assert_eq!(
+            client.authorization_header_value(),
+            "Bearer normalized-secret"
+        );
+        fs::remove_file(path).unwrap();
+    }
+
+    #[test]
+    fn client_debug_and_errors_never_include_token_value() {
+        let client = BackendApiClient::from_access_token_for_test(
+            "http://localhost:8787",
+            "never-print-this-token",
+        )
+        .unwrap();
+        assert!(!format!("{client:?}").contains("never-print-this-token"));
+        assert!(
+            !BackendApiClientError::Unauthorized {
+                origin: client.origin().clone()
+            }
+            .to_string()
+            .contains("never-print-this-token")
+        );
+    }
+
+    #[test]
+    fn authenticated_requests_follow_only_same_origin_redirects() {
+        let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+        let origin = format!("http://{}", listener.local_addr().unwrap());
+        let handle = thread::spawn(move || {
+            for response in [
+                "HTTP/1.1 302 Found\r\nLocation: /final\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+                "HTTP/1.1 200 OK\r\nContent-Length: 0\r\nConnection: close\r\n\r\n",
+            ] {
+                let (mut stream, _) = listener.accept().unwrap();
+                let mut request = vec![0; 4096];
+                let read = stream.read(&mut request).unwrap();
+                let request = String::from_utf8_lossy(&request[..read]).to_ascii_lowercase();
+                assert!(request.contains("authorization: bearer redirect-secret\r\n"));
+                stream.write_all(response.as_bytes()).unwrap();
+            }
+        });
+        let client =
+            BackendApiClient::from_access_token_for_test(&origin, "redirect-secret").unwrap();
+        let response = client
+            .blocking_request(Method::GET, "/start")
+            .unwrap()
+            .send()
+            .unwrap();
+        assert_eq!(response.status(), StatusCode::OK);
+        handle.join().unwrap();
+    }
+
+    #[test]
+    fn authenticated_requests_reject_cross_origin_redirects_without_leaking_token() {
+        let source = TcpListener::bind("127.0.0.1:0").unwrap();
+        let target = TcpListener::bind("127.0.0.1:0").unwrap();
+        target.set_nonblocking(true).unwrap();
+        let source_origin = format!("http://{}", source.local_addr().unwrap());
+        let target_origin = format!("http://{}", target.local_addr().unwrap());
+        let location = format!("{target_origin}/capture");
+        let handle = thread::spawn(move || {
+            let (mut stream, _) = source.accept().unwrap();
+            let mut request = vec![0; 4096];
+            let read = stream.read(&mut request).unwrap();
+            let request = String::from_utf8_lossy(&request[..read]).to_ascii_lowercase();
+            assert!(request.contains("authorization: bearer redirect-secret\r\n"));
+            let response = format!(
+                "HTTP/1.1 302 Found\r\nLocation: {location}\r\nContent-Length: 0\r\nConnection: close\r\n\r\n"
+            );
+            stream.write_all(response.as_bytes()).unwrap();
+        });
+        let client =
+            BackendApiClient::from_access_token_for_test(&source_origin, "redirect-secret")
+                .unwrap();
+        let error = client
+            .blocking_request(Method::GET, "/start")
+            .unwrap()
+            .send()
+            .unwrap_err();
+        let message = error.to_string();
+        assert!(message.contains("redirect"));
+        assert!(!message.contains("redirect-secret"));
+        handle.join().unwrap();
+        thread::sleep(Duration::from_millis(20));
+        assert!(matches!(
+            target.accept(),
+            Err(error) if error.kind() == std::io::ErrorKind::WouldBlock
+        ));
+    }
+
+    #[test]
+    fn status_diagnostics_distinguish_unauthorized_and_forbidden() {
+        let client =
+            BackendApiClient::from_access_token_for_test("http://localhost:8787", "secret")
+                .unwrap();
+        assert!(matches!(
+            client.check_status(StatusCode::UNAUTHORIZED),
+            Err(BackendApiClientError::Unauthorized { .. })
+        ));
+        assert!(matches!(
+            client.check_status(StatusCode::FORBIDDEN),
+            Err(BackendApiClientError::Forbidden { .. })
+        ));
+    }
+}
@@ -1,3 +1,4 @@
+use crate::BackendOrigin;
 use serde::{Deserialize, Serialize};
 use std::fmt;
 use std::time::Duration;
@@ -9,9 +10,11 @@ pub struct BackendAuthTarget {

 impl BackendAuthTarget {
    pub fn new(base_url: impl Into<String>) -> Self {
-        Self {
-            base_url: base_url.into(),
-        }
+        let base_url = base_url.into();
+        let base_url = BackendOrigin::parse(&base_url)
+            .map(|origin| origin.to_string())
+            .unwrap_or(base_url);
+        Self { base_url }
    }

    fn api_url(&self, path: &str) -> String {
@@ -1,12 +1,11 @@
-use futures::{SinkExt, StreamExt};
-use protocol::stream::{decode_event, encode_method};
-use protocol::{ErrorCode, Event, Method};
-use std::collections::VecDeque;
+use crate::transport::websocket::{Socket as WebSocket, SocketError as WebSocketError};
+use crate::{BackendApiClient, BackendApiClientError, Client};
+use reqwest::Method as HttpMethod;
+use serde::Deserialize;
 use std::fmt;
-use tokio::sync::mpsc;
-use tokio_tungstenite::connect_async;
-use tokio_tungstenite::tungstenite::Message as TungsteniteMessage;
-pub use workdir::workspace::WorkingDirectorySummary as BackendWorkingDirectorySummary;
+use tokio_tungstenite::tungstenite::client::IntoClientRequest;
+use tokio_tungstenite::tungstenite::http::HeaderValue;
+use tokio_tungstenite::tungstenite::http::header::AUTHORIZATION;
 pub use workspace_api::{
    Diagnostic as BackendDiagnostic, DiagnosticSeverity as BackendDiagnosticSeverity,
    ListResponse as BackendRuntimeListResponse, RuntimeSummary as BackendRuntimeSummary,
@@ -15,6 +14,11 @@ pub use workspace_api::{
    WorkerRestoreResponse as BackendWorkerRestoreResponse,
    WorkerRestoreResult as BackendWorkerRestoreResult, WorkerSummary as BackendWorkerSummary,
    WorkerWorkspaceSummary as BackendWorkerWorkspaceSummary,
+    WorkingDirectoryCreateRequest as BackendWorkingDirectoryCreateRequest,
+    WorkingDirectoryCreateResponse as BackendWorkingDirectoryCreateResponse,
+    WorkingDirectoryDetailResponse as BackendWorkingDirectoryDetailResponse,
+    WorkingDirectoryListResponse as BackendWorkingDirectoryListResponse,
+    WorkingDirectorySummary as BackendWorkingDirectorySummary,
 };

 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -48,6 +52,123 @@ impl BackendRuntimeTarget {
    pub fn display_label(&self) -> String {
        format!("{}:{}", self.runtime_id, self.worker_id)
    }
+
+    pub async fn upload_file(
+        &self,
+        file_name: &str,
+        media_type: &str,
+        content: Vec<u8>,
+    ) -> Result<protocol::UploadedFileRef, BackendRuntimeClientError> {
+        self.upload_file_with_id(
+            &uuid::Uuid::now_v7().to_string(),
+            file_name,
+            media_type,
+            content,
+        )
+        .await
+    }
+
+    pub async fn upload_file_with_id(
+        &self,
+        upload_id: &str,
+        file_name: &str,
+        media_type: &str,
+        content: Vec<u8>,
+    ) -> Result<protocol::UploadedFileRef, BackendRuntimeClientError> {
+        let api = BackendApiClient::from_stored_token(&self.base_url)?;
+        let worker_path = format!(
+            "/api/w/{}/runtimes/{}/workers/{}",
+            path_segment_encode(&self.workspace_id),
+            path_segment_encode(&self.runtime_id),
+            path_segment_encode(&self.worker_id),
+        );
+        let grant_path = format!(
+            "{worker_path}/attachment-upload-grants?file_name={}&media_type={}&upload_id={}",
+            path_segment_encode(file_name),
+            path_segment_encode(media_type),
+            path_segment_encode(&upload_id),
+        );
+        let grant_response = api
+            .request(HttpMethod::POST, &grant_path)?
+            .send()
+            .await
+            .map_err(BackendRuntimeClientError::Http)?;
+        api.check_status(grant_response.status())?;
+        let grant = grant_response
+            .json::<AttachmentUploadGrantResponse>()
+            .await
+            .map_err(BackendRuntimeClientError::Http)?;
+        let upload_path = format!(
+            "{worker_path}/attachment-uploads/{}",
+            path_segment_encode(&grant.upload_id),
+        );
+        let response = api
+            .request(HttpMethod::PUT, &upload_path)?
+            .body(content)
+            .send()
+            .await
+            .map_err(BackendRuntimeClientError::Http)?;
+        api.check_status(response.status())?;
+        response
+            .json::<UploadedFileResponse>()
+            .await
+            .map(|response| response.file)
+            .map_err(BackendRuntimeClientError::Http)
+    }
+
+    pub async fn cancel_file_upload(
+        &self,
+        upload_id: &str,
+    ) -> Result<(), BackendRuntimeClientError> {
+        let api = BackendApiClient::from_stored_token(&self.base_url)?;
+        let path = format!(
+            "/api/w/{}/runtimes/{}/workers/{}/attachment-uploads/{}",
+            path_segment_encode(&self.workspace_id),
+            path_segment_encode(&self.runtime_id),
+            path_segment_encode(&self.worker_id),
+            path_segment_encode(upload_id),
+        );
+        let response = api
+            .request(HttpMethod::DELETE, &path)?
+            .send()
+            .await
+            .map_err(BackendRuntimeClientError::Http)?;
+        api.check_status(response.status())?;
+        Ok(())
+    }
+
+    pub async fn delete_uploaded_file(
+        &self,
+        artifact_id: &str,
+    ) -> Result<(), BackendRuntimeClientError> {
+        let api = BackendApiClient::from_stored_token(&self.base_url)?;
+        let path = format!(
+            "/api/w/{}/runtimes/{}/workers/{}/attachments/{}",
+            path_segment_encode(&self.workspace_id),
+            path_segment_encode(&self.runtime_id),
+            path_segment_encode(&self.worker_id),
+            path_segment_encode(artifact_id),
+        );
+        let response = api
+            .request(HttpMethod::DELETE, &path)?
+            .send()
+            .await
+            .map_err(BackendRuntimeClientError::Http)?;
+        api.check_status(response.status())?;
+        Ok(())
+    }
+}
+
+#[derive(Deserialize)]
+struct AttachmentUploadGrantResponse {
+    upload_id: String,
+    #[allow(dead_code)]
+    expires_at_ms: u64,
+}
+
+#[derive(Deserialize)]
+struct UploadedFileResponse {
+    file: protocol::UploadedFileRef,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -101,32 +222,33 @@ impl BackendRuntimeListTarget {
    }
 }

-#[derive(Debug)]
-pub struct BackendRuntimeClient {
-    target: BackendRuntimeTarget,
-    command_tx: mpsc::UnboundedSender<Method>,
-    events: mpsc::UnboundedReceiver<Event>,
-    diagnostics: VecDeque<Event>,
-    _protocol_task: tokio::task::JoinHandle<()>,
-}
-
 #[derive(Debug)]
 pub enum BackendRuntimeClientError {
    InvalidTarget(String),
+    Api(BackendApiClientError),
    Http(reqwest::Error),
+    Protocol(String),
 }

 impl fmt::Display for BackendRuntimeClientError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::InvalidTarget(message) => f.write_str(message),
+            Self::Api(error) => write!(f, "{error}"),
            Self::Http(error) => write!(f, "{error}"),
+            Self::Protocol(message) => f.write_str(message),
        }
    }
 }

 impl std::error::Error for BackendRuntimeClientError {}

+impl From<BackendApiClientError> for BackendRuntimeClientError {
+    fn from(error: BackendApiClientError) -> Self {
+        Self::Api(error)
+    }
+}
+
 impl From<reqwest::Error> for BackendRuntimeClientError {
    fn from(error: reqwest::Error) -> Self {
        Self::Http(error)
@@ -137,7 +259,7 @@ pub async fn list_backend_workers(
    target: &BackendRuntimeListTarget,
 ) -> Result<BackendRuntimeListResponse<BackendWorkerSummary>, BackendRuntimeClientError> {
    validate_list_target(target)?;
-    let http = reqwest::Client::new();
+    let api = BackendApiClient::from_stored_token(&target.base_url)?;
    if let Some(runtime_id) = target.runtime_id.as_deref() {
        let path = backend_runtime_workers_path(
            target
@@ -146,12 +268,9 @@ pub async fn list_backend_workers(
                .expect("validated Backend Workspace scope"),
            runtime_id,
        );
-        let url = join_base_and_path(&target.base_url, &path);
-        return Ok(http
-            .get(url)
-            .send()
-            .await?
-            .error_for_status()?
+        let response = api.request(HttpMethod::GET, &path)?.send().await?;
+        api.check_status(response.status())?;
+        return Ok(response
            .json::<BackendRuntimeListResponse<BackendWorkerSummary>>()
            .await?);
    }
@@ -162,12 +281,9 @@ pub async fn list_backend_workers(
            .as_deref()
            .expect("validated Backend Workspace scope"),
    );
-    let runtime_url = join_base_and_path(&target.base_url, &runtime_path);
-    let runtimes = http
-        .get(runtime_url)
-        .send()
-        .await?
-        .error_for_status()?
+    let response = api.request(HttpMethod::GET, &runtime_path)?.send().await?;
+    api.check_status(response.status())?;
+    let runtimes = response
        .json::<BackendRuntimeListResponse<BackendRuntimeSummary>>()
        .await?;

@@ -181,29 +297,43 @@ pub async fn list_backend_workers(
                .expect("validated Backend Workspace scope"),
            &runtime.runtime_id,
        );
-        let url = join_base_and_path(&target.base_url, &path);
-        match http
-            .get(url)
-            .send()
-            .await
-            .and_then(|response| response.error_for_status())
-        {
-            Ok(response) => {
-                let response = response
-                    .json::<BackendRuntimeListResponse<BackendWorkerSummary>>()
-                    .await?;
-                diagnostics.extend(response.diagnostics);
-                items.extend(response.items);
-            }
-            Err(error) => diagnostics.push(BackendDiagnostic {
+        let response = match api.request(HttpMethod::GET, &path)?.send().await {
+            Ok(response) => response,
+            Err(error) => {
+                diagnostics.push(BackendDiagnostic {
                    code: "runtime_worker_list_failed".to_string(),
                    severity: BackendDiagnosticSeverity::Error,
                    message: format!(
                        "failed to list workers for runtime {}: {error}",
                        runtime.runtime_id
                    ),
-            }),
+                });
+                continue;
            }
+        };
+        if matches!(
+            response.status(),
+            reqwest::StatusCode::UNAUTHORIZED | reqwest::StatusCode::FORBIDDEN
+        ) {
+            api.check_status(response.status())?;
+        }
+        if !response.status().is_success() {
+            diagnostics.push(BackendDiagnostic {
+                code: "runtime_worker_list_failed".to_string(),
+                severity: BackendDiagnosticSeverity::Error,
+                message: format!(
+                    "failed to list workers for runtime {}: Backend returned HTTP {}",
+                    runtime.runtime_id,
+                    response.status().as_u16()
+                ),
+            });
+            continue;
+        }
+        let response = response
+            .json::<BackendRuntimeListResponse<BackendWorkerSummary>>()
+            .await?;
+        diagnostics.extend(response.diagnostics);
+        items.extend(response.items);
    }

    Ok(BackendRuntimeListResponse {
@@ -224,7 +354,7 @@ pub async fn list_backend_stopped_workers(
            "stopped worker listing requires a runtime id".to_string(),
        ));
    };
-    let http = reqwest::Client::new();
+    let api = BackendApiClient::from_stored_token(&target.base_url)?;
    let path = backend_runtime_workers_path(
        target
            .workspace_id
@@ -232,12 +362,12 @@ pub async fn list_backend_stopped_workers(
            .expect("validated Backend Workspace scope"),
        runtime_id,
    );
-    let url = join_base_and_path(&target.base_url, &format!("{path}?status=stopped"));
-    Ok(http
-        .get(url)
+    let response = api
+        .request(HttpMethod::GET, &format!("{path}?status=stopped"))?
        .send()
-        .await?
-        .error_for_status()?
+        .await?;
+    api.check_status(response.status())?;
+    Ok(response
        .json::<BackendRuntimeListResponse<BackendWorkerSummary>>()
        .await?)
 }
@@ -246,166 +376,61 @@ pub async fn restore_backend_worker(
    target: &BackendRuntimeTarget,
 ) -> Result<BackendWorkerRestoreResponse, BackendRuntimeClientError> {
    validate_target(target)?;
-    let http = reqwest::Client::new();
+    let api = BackendApiClient::from_stored_token(&target.base_url)?;
    let path = backend_runtime_worker_restore_path(
        &target.workspace_id,
        &target.runtime_id,
        &target.worker_id,
    );
-    let url = join_base_and_path(&target.base_url, &path);
-    Ok(http
-        .post(url)
+    let response = api
+        .request(HttpMethod::POST, &path)?
        .json(&serde_json::json!({}))
        .send()
-        .await?
-        .error_for_status()?
-        .json::<BackendWorkerRestoreResponse>()
-        .await?)
+        .await?;
+    let response = api.require_success(response).await?;
+    Ok(response.json::<BackendWorkerRestoreResponse>().await?)
 }

-impl BackendRuntimeClient {
-    pub async fn connect(target: BackendRuntimeTarget) -> Result<Self, BackendRuntimeClientError> {
+pub async fn connect_backend_runtime(
+    target: BackendRuntimeTarget,
+) -> Result<Client<WebSocket>, BackendRuntimeClientError> {
    validate_target(&target)?;
-        let (event_tx, rx) = mpsc::unbounded_channel();
-        let (command_tx, command_rx) = mpsc::unbounded_channel();
-
-        let protocol_target = target.clone();
-        let protocol_event_tx = event_tx.clone();
-        let protocol_task = tokio::spawn(async move {
-            run_worker_protocol_transport(protocol_target, command_rx, protocol_event_tx).await;
-        });
-
-        Ok(Self {
-            target,
-            command_tx,
-            events: rx,
-            diagnostics: VecDeque::new(),
-            _protocol_task: protocol_task,
-        })
-    }
-
-    pub fn try_next_event(&mut self) -> Option<Event> {
-        if let Some(event) = self.diagnostics.pop_front() {
-            return Some(event);
-        }
-        self.events.try_recv().ok()
-    }
-
-    pub async fn next_event(&mut self) -> Option<Event> {
-        if let Some(event) = self.diagnostics.pop_front() {
-            return Some(event);
-        }
-        self.events.recv().await
-    }
-
-    pub async fn send(&mut self, method: &Method) -> Result<(), BackendRuntimeClientError> {
-        self.command_tx.send(method.clone()).map_err(|_| {
-            BackendRuntimeClientError::InvalidTarget(format!(
-                "Backend protocol command stream is closed for {}",
-                self.target.display_label()
+    let api = BackendApiClient::from_stored_token(&target.base_url)?;
+    let request = protocol_ws_request(&target, &api).map_err(|error| {
+        BackendRuntimeClientError::Protocol(format!(
+            "Backend protocol request could not be constructed for {}: {error}",
+            target.display_label()
        ))
    })?;
-        Ok(())
+    match WebSocket::connect(request).await {
+        Ok(socket) => Ok(Client::new(socket)),
+        Err(WebSocketError::WebSocket(error)) => Err(BackendRuntimeClientError::Protocol(
+            protocol_connect_error_message(&target, &api, &error),
+        )),
    }
 }

-impl Drop for BackendRuntimeClient {
-    fn drop(&mut self) {
-        self._protocol_task.abort();
-    }
-}
-
-async fn run_worker_protocol_transport(
-    target: BackendRuntimeTarget,
-    mut commands: mpsc::UnboundedReceiver<Method>,
-    tx: mpsc::UnboundedSender<Event>,
-) {
-    let url = protocol_ws_url(&target);
-    match connect_async(&url).await {
-        Ok((ws, _)) => {
-            let (mut sink, mut stream) = ws.split();
-            loop {
-                tokio::select! {
-                    maybe_method = commands.recv() => {
-                        let Some(method) = maybe_method else {
-                            break;
-                        };
-                        match encode_method(&method) {
-                            Ok(text) => {
-                                if let Err(error) = sink.send(TungsteniteMessage::Text(text.into())).await {
-                                    let _ = tx.send(diagnostic_event(format!(
-                                        "Backend protocol command send failed for {}: {error}",
-                                        target.display_label()
-                                    )));
-                                    break;
-                                }
-                            }
-                            Err(error) => {
-                                let _ = tx.send(diagnostic_event(format!(
-                                    "Backend protocol command could not serialize method for {}: {error}",
-                                    target.display_label()
-                                )));
-                            }
-                        }
-                    }
-                    frame = stream.next() => {
-                        match frame {
-                            Some(Ok(TungsteniteMessage::Text(text))) => {
-                                match decode_event(&text) {
-                                    Ok(event) => {
-                                        let _ = tx.send(event);
-                                    }
-                                    Err(error) => {
-                                        let _ = tx.send(diagnostic_event(format!(
-                                            "Backend protocol response was not valid Event JSON for {}: {error}",
-                                            target.display_label()
-                                        )));
-                                    }
-                                }
-                            }
-                            Some(Ok(TungsteniteMessage::Close(_))) | None => {
-                                let _ = tx.send(diagnostic_event(format!(
-                                    "Backend protocol command stream closed for {}",
-                                    target.display_label()
-                                )));
-                                break;
-                            }
-                            Some(Ok(TungsteniteMessage::Ping(_)))
-                            | Some(Ok(TungsteniteMessage::Pong(_)))
-                            | Some(Ok(TungsteniteMessage::Binary(_)))
-                            | Some(Ok(TungsteniteMessage::Frame(_))) => {}
-                            Some(Err(error)) => {
-                                let _ = tx.send(diagnostic_event(format!(
-                                    "Backend protocol WebSocket error for {}: {error}",
-                                    target.display_label()
-                                )));
-                                break;
+fn protocol_connect_error_message(
+    target: &BackendRuntimeTarget,
+    api: &BackendApiClient,
+    error: &tokio_tungstenite::tungstenite::Error,
+) -> String {
+    if let tokio_tungstenite::tungstenite::Error::Http(response) = error {
+        if let Ok(status) = reqwest::StatusCode::from_u16(response.status().as_u16()) {
+            if matches!(
+                status,
+                reqwest::StatusCode::UNAUTHORIZED | reqwest::StatusCode::FORBIDDEN
+            ) {
+                if let Err(error) = api.check_status(status) {
+                    return error.to_string();
                }
            }
        }
    }
-            }
-        }
-        Err(error) => {
-            let _ = tx.send(diagnostic_event(format!(
+    format!(
        "Backend protocol WebSocket connect failed for {}: {error}",
        target.display_label()
-            )));
-            while commands.recv().await.is_some() {
-                let _ = tx.send(diagnostic_event(format!(
-                    "Backend protocol command was not sent because command stream is unavailable for {}",
-                    target.display_label()
-                )));
-            }
-        }
-    }
-}
-
-fn diagnostic_event(message: impl Into<String>) -> Event {
-    Event::Error {
-        code: ErrorCode::Internal,
-        message: message.into(),
-    }
+    )
 }

 fn validate_target(target: &BackendRuntimeTarget) -> Result<(), BackendRuntimeClientError> {
@@ -496,6 +521,19 @@ fn backend_runtime_worker_restore_path(
    )
 }

+fn protocol_ws_request(
+    target: &BackendRuntimeTarget,
+    api: &BackendApiClient,
+) -> Result<tokio_tungstenite::tungstenite::http::Request<()>, String> {
+    let mut request = protocol_ws_url(target)
+        .into_client_request()
+        .map_err(|error| error.to_string())?;
+    let value = HeaderValue::from_str(&api.authorization_header_value())
+        .map_err(|_| "saved Backend token is not a valid Authorization header".to_string())?;
+    request.headers_mut().insert(AUTHORIZATION, value);
+    Ok(request)
+}
+
 fn protocol_ws_url(target: &BackendRuntimeTarget) -> String {
    let path = format!(
        "/api/w/{}/runtimes/{}/workers/{}/protocol/ws",
@@ -557,6 +595,26 @@ mod tests {
        );
    }

+    #[test]
+    fn protocol_request_attaches_saved_bearer_authorization() {
+        let target = BackendRuntimeTarget::new(
+            "http://127.0.0.1:8787/",
+            "workspace alpha",
+            "runtime/one",
+            "worker one",
+        );
+        let api = BackendApiClient::from_access_token_for_test(
+            "http://127.0.0.1:8787",
+            "websocket-secret",
+        )
+        .unwrap();
+        let request = protocol_ws_request(&target, &api).unwrap();
+        assert_eq!(
+            request.headers().get(AUTHORIZATION).unwrap(),
+            "Bearer websocket-secret"
+        );
+    }
+
    #[test]
    fn backend_worker_summary_decodes_current_occupied_workdir_contract() {
        let payload = serde_json::json!({
@@ -572,7 +630,7 @@ mod tests {
            "capabilities": {"can_stop": true, "can_spawn_followup": false},
            "working_directory": {
                "working_directory_id": "wd-1",
-                "repository_id": "main",
+                "repository_key": "main",
                "materializer_kind": "local_git_worktree",
                "status": "active",
                "occupied_by": {
@@ -585,13 +643,11 @@ mod tests {
        });

        let worker: BackendWorkerSummary = serde_json::from_value(payload.clone()).unwrap();
-        let occupied_by = worker
-            .working_directory
-            .unwrap()
-            .occupied_by
-            .expect("occupied Workdir");
-        assert_eq!(occupied_by.worker.runtime_id, "arcadia");
-        assert_eq!(occupied_by.worker.worker_id, "worker-opaque-64");
+        let workdir = worker.working_directory.unwrap();
+        assert_eq!(workdir.repository_key, "main");
+        let occupied_by = workdir.occupied_by.expect("occupied Workdir");
+        assert_eq!(occupied_by.runtime_id, "arcadia");
+        assert_eq!(occupied_by.worker_id, "worker-opaque-64");

        let mut stale = payload;
        stale["working_directory"]["occupied_by"]["runtime_worker_id"] = serde_json::json!(64);
@@ -1,17 +1,17 @@
+use crate::{BackendApiClient, BackendApiClientError};
+use reqwest::Method;
 use serde::{Deserialize, Serialize};
 use std::fmt;
+use workspace_api::{
+    WorkspaceCatalogListResponse, WorkspaceCreateResponse, WorkspaceRepositoryRecord,
+    WorkspaceSummary,
+};

 const DEFAULT_WORKSPACE_LIMIT: usize = 200;

-#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
-pub struct BackendWorkspace {
-    pub workspace_id: String,
-    pub owner_account_id: Option<String>,
-    pub display_name: String,
-    pub state: String,
-    pub created_at: String,
-    pub updated_at: String,
-}
+pub type BackendWorkspace = WorkspaceSummary;
+pub type CreateBackendWorkspaceResponse = WorkspaceCreateResponse;
+pub type CreateBackendWorkspaceRepositoryRecord = WorkspaceRepositoryRecord;

 #[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 #[serde(deny_unknown_fields)]
@@ -29,25 +29,6 @@ pub struct CreateBackendWorkspaceRepository {
    pub default_ref: Option<String>,
 }

-#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
-pub struct CreateBackendWorkspaceResponse {
-    pub workspace: BackendWorkspace,
-    pub repository: CreateBackendWorkspaceRepositoryRecord,
-    pub config_revision: u64,
-    pub request_fingerprint: String,
-    pub replayed: bool,
-}
-
-#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
-pub struct CreateBackendWorkspaceRepositoryRecord {
-    pub workspace_id: String,
-    pub repository_id: String,
-    pub name: String,
-    pub kind: String,
-    pub uri: String,
-    pub default_ref: Option<String>,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct BackendWorkspaceCatalogTarget {
    pub base_url: String,
@@ -64,7 +45,7 @@ impl BackendWorkspaceCatalogTarget {
 #[derive(Debug)]
 pub enum BackendWorkspaceClientError {
    InvalidTarget(String),
-    RequestFailed { status: u16, message: String },
+    Api(BackendApiClientError),
    Http(reqwest::Error),
 }

@@ -72,9 +53,7 @@ impl fmt::Display for BackendWorkspaceClientError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::InvalidTarget(message) => f.write_str(message),
-            Self::RequestFailed { status, message } => {
-                write!(f, "Backend request failed with HTTP {status}: {message}")
-            }
+            Self::Api(error) => write!(f, "{error}"),
            Self::Http(error) => write!(f, "{error}"),
        }
    }
@@ -82,6 +61,12 @@ impl fmt::Display for BackendWorkspaceClientError {

 impl std::error::Error for BackendWorkspaceClientError {}

+impl From<BackendApiClientError> for BackendWorkspaceClientError {
+    fn from(error: BackendApiClientError) -> Self {
+        Self::Api(error)
+    }
+}
+
 impl From<reqwest::Error> for BackendWorkspaceClientError {
    fn from(error: reqwest::Error) -> Self {
        Self::Http(error)
@@ -91,56 +76,72 @@ impl From<reqwest::Error> for BackendWorkspaceClientError {
 pub async fn list_backend_workspaces(
    target: &BackendWorkspaceCatalogTarget,
 ) -> Result<Vec<BackendWorkspace>, BackendWorkspaceClientError> {
-    validate_target(target)?;
-    let url = format!(
-        "{}/api/workspaces?limit={DEFAULT_WORKSPACE_LIMIT}",
-        target.base_url.trim_end_matches('/')
-    );
-    let response = reqwest::Client::new().get(url).send().await?;
-    let response = require_success(response).await?;
-    Ok(response.json::<Vec<BackendWorkspace>>().await?)
+    let client = BackendApiClient::from_stored_token(&target.base_url)?;
+    list_backend_workspaces_with_client(&client).await
+}
+
+async fn list_backend_workspaces_with_client(
+    client: &BackendApiClient,
+) -> Result<Vec<BackendWorkspace>, BackendWorkspaceClientError> {
+    let response = client
+        .request(
+            Method::GET,
+            &format!("/api/workspaces?limit={DEFAULT_WORKSPACE_LIMIT}"),
+        )?
+        .send()
+        .await?;
+    client.check_status(response.status())?;
+    Ok(response.json::<WorkspaceCatalogListResponse>().await?.0)
 }

 pub async fn create_backend_workspace(
    target: &BackendWorkspaceCatalogTarget,
    request: &CreateBackendWorkspaceRequest,
 ) -> Result<CreateBackendWorkspaceResponse, BackendWorkspaceClientError> {
-    validate_target(target)?;
-    let url = format!("{}/api/workspaces", target.base_url.trim_end_matches('/'));
-    let response = reqwest::Client::new()
-        .post(url)
+    let client = BackendApiClient::from_stored_token(&target.base_url)?;
+    let response = client
+        .request(Method::POST, "/api/workspaces")?
        .json(request)
        .send()
        .await?;
-    let response = require_success(response).await?;
+    client.check_status(response.status())?;
    Ok(response.json::<CreateBackendWorkspaceResponse>().await?)
 }

-async fn require_success(
-    response: reqwest::Response,
-) -> Result<reqwest::Response, BackendWorkspaceClientError> {
-    if response.status().is_success() {
-        return Ok(response);
-    }
-    let status = response.status().as_u16();
-    let message = response.text().await.unwrap_or_default();
-    Err(BackendWorkspaceClientError::RequestFailed { status, message })
-}
-
-fn validate_target(
-    target: &BackendWorkspaceCatalogTarget,
-) -> Result<(), BackendWorkspaceClientError> {
-    if !(target.base_url.starts_with("http://") || target.base_url.starts_with("https://")) {
-        return Err(BackendWorkspaceClientError::InvalidTarget(
-            "Backend API base URL must start with http:// or https://".to_string(),
-        ));
-    }
-    Ok(())
-}
-
 #[cfg(test)]
 mod tests {
    use super::*;
+    use std::io::{Read, Write};
+    use std::net::TcpListener;
+    use std::thread;
+
+    #[tokio::test]
+    async fn workspace_catalog_request_uses_shared_bearer_client() {
+        let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+        let base_url = format!("http://{}", listener.local_addr().unwrap());
+        let handle = thread::spawn(move || {
+            let (mut stream, _) = listener.accept().unwrap();
+            let mut request = vec![0; 4096];
+            let read = stream.read(&mut request).unwrap();
+            let request = String::from_utf8_lossy(&request[..read]).to_ascii_lowercase();
+            assert!(request.starts_with("get /api/workspaces?limit=200 "));
+            assert!(request.contains("authorization: bearer catalog-secret\r\n"));
+            stream
+                .write_all(
+                    b"HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: 2\r\nConnection: close\r\n\r\n[]",
+                )
+                .unwrap();
+        });
+        let client =
+            BackendApiClient::from_access_token_for_test(&base_url, "catalog-secret").unwrap();
+        assert!(
+            list_backend_workspaces_with_client(&client)
+                .await
+                .unwrap()
+                .is_empty()
+        );
+        handle.join().unwrap();
+    }

    #[test]
    fn create_request_keeps_operation_key_for_exact_retry() {
@@ -0,0 +1,137 @@
+use std::error::Error;
+use std::fmt;
+
+use protocol::stream::{decode_event, encode_method};
+use protocol::{Event, Method};
+
+use crate::transport::Socket;
+
+/// Typed Worker protocol client over an injected message transport.
+pub struct Client<T> {
+    socket: T,
+}
+
+#[derive(Debug)]
+pub enum ClientError<E> {
+    Transport(E),
+    Protocol(serde_json::Error),
+}
+
+impl<T> Client<T> {
+    pub fn new(socket: T) -> Self {
+        Self { socket }
+    }
+
+    pub fn into_inner(self) -> T {
+        self.socket
+    }
+}
+
+impl<T: Socket> Client<T> {
+    pub async fn send(&mut self, method: &Method) -> Result<(), ClientError<T::Error>> {
+        let message = encode_method(method).map_err(ClientError::Protocol)?;
+        self.socket
+            .send(message)
+            .await
+            .map_err(ClientError::Transport)
+    }
+
+    pub async fn next_event(&mut self) -> Result<Option<Event>, ClientError<T::Error>> {
+        self.socket
+            .next()
+            .await
+            .map_err(ClientError::Transport)?
+            .map(|message| decode_event(&message).map_err(ClientError::Protocol))
+            .transpose()
+    }
+
+    pub fn try_next_event(&mut self) -> Result<Option<Event>, ClientError<T::Error>> {
+        self.socket
+            .try_next()
+            .map_err(ClientError::Transport)?
+            .map(|message| decode_event(&message).map_err(ClientError::Protocol))
+            .transpose()
+    }
+}
+
+impl<E: fmt::Display> fmt::Display for ClientError<E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Transport(error) => write!(formatter, "Worker transport error: {error}"),
+            Self::Protocol(error) => write!(formatter, "Worker protocol error: {error}"),
+        }
+    }
+}
+
+impl<E: Error + 'static> Error for ClientError<E> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::Transport(error) => Some(error),
+            Self::Protocol(error) => Some(error),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::VecDeque;
+    use std::convert::Infallible;
+
+    use async_trait::async_trait;
+    use protocol::stream::{decode_method, encode_event};
+    use protocol::{Event, Method, WorkerStatus};
+
+    use super::Client;
+    use crate::transport::Socket;
+
+    #[derive(Default)]
+    struct TestSocket {
+        sent: Vec<String>,
+        incoming: VecDeque<String>,
+    }
+
+    #[async_trait]
+    impl Socket for TestSocket {
+        type Error = Infallible;
+
+        async fn send(&mut self, message: String) -> Result<(), Self::Error> {
+            self.sent.push(message);
+            Ok(())
+        }
+
+        async fn next(&mut self) -> Result<Option<String>, Self::Error> {
+            Ok(self.incoming.pop_front())
+        }
+
+        fn try_next(&mut self) -> Result<Option<String>, Self::Error> {
+            Ok(self.incoming.pop_front())
+        }
+    }
+
+    #[tokio::test]
+    async fn encodes_methods_and_decodes_events_above_transport() {
+        let mut socket = TestSocket::default();
+        socket.incoming.push_back(
+            encode_event(&Event::Status {
+                status: WorkerStatus::Idle,
+            })
+            .expect("encode event"),
+        );
+        let mut client = Client::new(socket);
+
+        client
+            .send(&Method::run_text("hello"))
+            .await
+            .expect("send method");
+        assert!(matches!(
+            decode_method(&client.socket.sent[0]),
+            Ok(Method::Run { .. })
+        ));
+        assert!(matches!(
+            client.next_event().await,
+            Ok(Some(Event::Status {
+                status: WorkerStatus::Idle
+            }))
+        ));
+    }
+}
@@ -1,57 +1,48 @@
-//! Worker プロトコルを喋るクライアント。
+//! Backend Workspace/Runtime と既存 Worker protocol へ接続するクライアント。
 //!
-//! - [`WorkerClient`]: 既存 worker の Unix ソケットへ接続して `Method` を送り、
-//!   `Event` を受け取る低レベル接続。
-//! - [`spawn`]: worker バイナリをサブプロセスとして起動し、`YOI-READY`
-//!   ハンドシェイクが終わるまで待つフロー。subprocess を立ち上げる必要が
-//!   ない呼び出し側 (=既存 worker に attach する場合) は使わなくてよい。
-//!
-//! TUI / GUI / E2E ハーネスはこの crate に依存して protocol を喋る。
+//! Standalone execution is owned by the `standalone` crate and does not spawn
+//! a Worker subprocess through this crate.

-pub mod backend_auth;
+pub mod backend_api;
+mod backend_auth;
 pub mod backend_runtime;
 pub mod backend_workspace;
-pub mod runtime_command;
-pub mod spawn;
+mod client;
 pub mod target;
-pub mod ticket_role;
-mod worker_client;
+pub mod transport;
 mod workspace_product;

+pub use backend_api::{
+    BackendApiClient, BackendApiClientError, BackendOrigin, backend_token_file_path,
+    save_backend_token,
+};
 pub use backend_auth::{
    BackendAuthClientError, BackendAuthTarget, DeviceLoginPollResponse, DeviceLoginStartResponse,
    poll_device_login, start_device_login, wait_for_device_login,
 };
 pub use backend_runtime::{
-    BackendDiagnostic, BackendDiagnosticSeverity, BackendRuntimeClient, BackendRuntimeClientError,
+    BackendDiagnostic, BackendDiagnosticSeverity, BackendRuntimeClientError,
    BackendRuntimeListResponse, BackendRuntimeListTarget, BackendRuntimeSummary,
    BackendRuntimeTarget, BackendWorkerCapabilitySummary, BackendWorkerImplementationSummary,
    BackendWorkerRestoreResponse, BackendWorkerRestoreResult, BackendWorkerSummary,
-    BackendWorkerWorkspaceSummary, BackendWorkingDirectorySummary, list_backend_stopped_workers,
-    list_backend_workers, restore_backend_worker,
+    BackendWorkerWorkspaceSummary, BackendWorkingDirectorySummary, connect_backend_runtime,
+    list_backend_stopped_workers, list_backend_workers, restore_backend_worker,
 };
 pub use backend_workspace::{
    BackendWorkspace, BackendWorkspaceCatalogTarget, BackendWorkspaceClientError,
    CreateBackendWorkspaceRepository, CreateBackendWorkspaceRequest,
    CreateBackendWorkspaceResponse, create_backend_workspace, list_backend_workspaces,
 };
-pub use runtime_command::WorkerRuntimeCommand;
+pub use client::{Client, ClientError};
 pub use target::{
-    BackendTarget, Dashboard, LocalTarget, ResolvedTarget, Target, TargetError, TargetKind,
-    WorkerByName, WorkerConnection, WorkerConnectionSelector, WorkerList, WorkerListRequest,
-    WorkerResume, WorkerSpawn,
+    BackendTarget, Dashboard, ResolvedTarget, StandaloneTarget, StandaloneWorkerListIntent,
+    StandaloneWorkerResumeIntent, Target, TargetError, TargetKind, WorkerConnection,
+    WorkerConnectionSelector, WorkerList, WorkerListRequest, WorkerSpawn,
 };
-
-pub use spawn::{
-    SpawnConfig, SpawnError, SpawnReady, WorkerProcessLaunchConfig, WorkerProcessLaunchOptions,
-    spawn_worker, spawn_worker_with_options,
+pub use workspace_api::{
+    CompanionCancelRequest, CompanionLifecycleState, CompanionMessageDisposition,
+    CompanionMessageRequest, CompanionMessageResponse, CompanionStatusResponse,
+    CompanionTranscriptItem, CompanionTranscriptProjection, CompanionTranscriptRole,
+    CompanionTransportSummary, ObjectiveDetail, ObjectiveSummary,
 };
-pub use ticket_role::{
-    TicketRef, TicketRoleLaunchContext, TicketRoleLaunchError, TicketRoleLaunchOptions,
-    TicketRoleLaunchPlan, TicketRoleLaunchResult, TicketRolePreRunWarning,
-    launch_ticket_role_worker, launch_ticket_role_worker_with_options, plan_ticket_role_launch,
-    plan_ticket_role_launch_with_config,
-};
-pub use worker_client::WorkerClient;
-pub use workspace_api::{ObjectiveDetail, ObjectiveSummary};
 pub use workspace_product::BackendWorkspaceProductClient;
@@ -1,435 +0,0 @@
-//! Worker runtime command をサブプロセスとして立ち上げ、`YOI-READY` を待つ
-//! ハンドシェイク。
-//!
-//! - 親プロセス (TUI / GUI / E2E) は profile/default/typed restore flags を
-//!   指定してこの関数に渡す。worker はそれを受けて socket を bind し、stderr に
-//!   `YOI-READY\t<name>\t<socket>` を吐く。
-//! - 待機中の stderr 行は `progress` コールバック越しに呼び出し側へ流す。
-//!   UI の進捗表示や E2E のログ収集はここで賄う。
-//! - `kill_on_drop = false` + `process_group(0)` により、親プロセス
-//!   ライフサイクルから切り離した detached worker を作る。ready 後の lifecycle
-//!   管理は runtime ディレクトリ / socket を介して行う。
-
-use std::io;
-use std::path::{Path, PathBuf};
-use std::process::Stdio;
-use std::time::Duration;
-
-use crate::WorkerRuntimeCommand;
-use tokio::process::Command;
-use uuid::Uuid;
-
-const READY_PREFIX: &str = "YOI-READY\t";
-const READY_TIMEOUT: Duration = Duration::from_secs(20);
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct WorkerProcessLaunchConfig {
-    pub runtime_command: WorkerRuntimeCommand,
-    /// `worker.name` として使う識別子。runtime ディレクトリ
-    /// (`manifest::paths::worker_runtime_dir`) の解決と、ready 行に乗る
-    /// 名前との突き合わせに使う。
-    pub worker_name: String,
-    /// Optional reusable Profile selector. Worker identity is always supplied
-    /// separately with `--worker`; profile selection must not imply a name.
-    pub profile: Option<String>,
-    /// Explicit runtime workspace root. The child receives it via
-    /// `--workspace` so startup does not infer workspace identity from the
-    /// parent process cwd.
-    pub workspace_root: PathBuf,
-    /// Optional child process cwd. This is not runtime workspace identity and
-    /// is not passed as a CLI argument; the child observes it as its ordinary
-    /// process current directory.
-    pub cwd: Option<PathBuf>,
-    /// `Some(id)` のとき `--session <id>` を付与し、当該セッションから
-    /// resume させる。
-    pub resume_from: Option<Uuid>,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Default)]
-pub struct WorkerProcessLaunchOptions {
-    /// Extra child CLI arguments supplied by an upper resolver layer. The
-    /// low-level launch config intentionally does not model Ticket IDs,
-    /// Ticket roles, orchestration roles, executable authority, or raw
-    /// browser-provided profile/cwd/workspace inputs.
-    pub extra_args: Vec<String>,
-}
-
-impl WorkerProcessLaunchOptions {
-    pub fn with_hidden_arg(mut self, name: impl Into<String>, value: impl Into<String>) -> Self {
-        self.extra_args.extend([name.into(), value.into()]);
-        self
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.extra_args.is_empty()
-    }
-}
-
-pub type SpawnConfig = WorkerProcessLaunchConfig;
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct SpawnReady {
-    pub worker_name: String,
-    pub socket_path: PathBuf,
-}
-
-#[derive(Debug)]
-pub enum SpawnError {
-    Io(io::Error),
-    /// runtime ディレクトリが解決できなかった (環境変数未設定等)。
-    RuntimeDirUnavailable,
-    WorkerLaunchFailed {
-        command: WorkerRuntimeCommand,
-        source: io::Error,
-    },
-    WorkerExitedEarly {
-        stderr_tail: String,
-    },
-    Timeout,
-}
-
-impl std::fmt::Display for SpawnError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::Io(e) => write!(f, "io error: {e}"),
-            Self::RuntimeDirUnavailable => write!(
-                f,
-                "could not resolve runtime directory (set YOI_HOME, YOI_RUNTIME_DIR, XDG_RUNTIME_DIR, or HOME)"
-            ),
-            Self::WorkerLaunchFailed { command, source } => write!(
-                f,
-                "failed to launch worker runtime command `{command}`: {source}"
-            ),
-            Self::WorkerExitedEarly { stderr_tail } => {
-                if stderr_tail.is_empty() {
-                    write!(f, "worker exited before becoming ready")
-                } else {
-                    write!(f, "worker exited before becoming ready: {stderr_tail}")
-                }
-            }
-            Self::Timeout => write!(
-                f,
-                "worker did not become ready within {}s",
-                READY_TIMEOUT.as_secs()
-            ),
-        }
-    }
-}
-
-impl std::error::Error for SpawnError {
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-        match self {
-            Self::Io(error) | Self::WorkerLaunchFailed { source: error, .. } => Some(error),
-            Self::RuntimeDirUnavailable | Self::WorkerExitedEarly { .. } | Self::Timeout => None,
-        }
-    }
-}
-
-impl From<io::Error> for SpawnError {
-    fn from(e: io::Error) -> Self {
-        Self::Io(e)
-    }
-}
-
-fn runtime_args(
-    config: &WorkerProcessLaunchConfig,
-    options: &WorkerProcessLaunchOptions,
-) -> Vec<String> {
-    let mut args = vec![
-        "--workspace".to_string(),
-        config.workspace_root.display().to_string(),
-    ];
-    if let Some(id) = config.resume_from {
-        args.extend([
-            "--session".to_string(),
-            id.to_string(),
-            "--worker".to_string(),
-            config.worker_name.clone(),
-        ]);
-    } else {
-        args.extend(["--worker".to_string(), config.worker_name.clone()]);
-        if let Some(profile) = &config.profile {
-            args.extend(["--profile".to_string(), profile.clone()]);
-        }
-    }
-    args.extend(options.extra_args.clone());
-    args
-}
-
-/// worker を spawn し、`YOI-READY` ハンドシェイクが終わるまで待つ。
-///
-/// `progress` は ready 行を見つけるまでに観測した stderr の各行で呼ばれる
-/// (ready 行自体は除外される)。UI の表示更新や E2E ログ取得に使う。
-pub async fn spawn_worker<F>(
-    config: WorkerProcessLaunchConfig,
-    progress: F,
-) -> Result<SpawnReady, SpawnError>
-where
-    F: FnMut(&str),
-{
-    spawn_worker_with_options(config, WorkerProcessLaunchOptions::default(), progress).await
-}
-
-pub async fn spawn_worker_with_options<F>(
-    config: WorkerProcessLaunchConfig,
-    options: WorkerProcessLaunchOptions,
-    mut progress: F,
-) -> Result<SpawnReady, SpawnError>
-where
-    F: FnMut(&str),
-{
-    let worker_runtime_dir = manifest::paths::worker_runtime_dir(&config.worker_name)
-        .ok_or(SpawnError::RuntimeDirUnavailable)?;
-    std::fs::create_dir_all(&worker_runtime_dir).map_err(SpawnError::Io)?;
-    let stderr_path = worker_runtime_dir.join("stderr.log");
-    let stderr_file = std::fs::File::create(&stderr_path).map_err(SpawnError::Io)?;
-
-    let mut command = Command::new(config.runtime_command.program());
-    command
-        .args(config.runtime_command.prefix_args())
-        .current_dir(config.cwd.as_ref().unwrap_or(&config.workspace_root))
-        .stdin(Stdio::null())
-        .stdout(Stdio::null())
-        .stderr(Stdio::from(stderr_file))
-        .process_group(0);
-    for arg in runtime_args(&config, &options) {
-        command.arg(arg);
-    }
-    let mut child = command
-        .spawn()
-        .map_err(|source| SpawnError::WorkerLaunchFailed {
-            command: config.runtime_command.clone(),
-            source,
-        })?;
-
-    // Default `kill_on_drop = false` plus `process_group(0)` makes this
-    // a detached Worker once startup succeeds: dropping the handle does not
-    // terminate it, and terminal-generated signals for the parent's
-    // process group do not hit the Worker. Runtime state/socket files are
-    // the source of truth after that point.
-    let ready = match wait_for_ready_file(&mut progress, &stderr_path, &mut child).await {
-        Ok(ready) => ready,
-        Err(e) => {
-            let _ = child.start_kill();
-            let _ = child.wait().await;
-            return Err(e);
-        }
-    };
-    tokio::spawn(async move {
-        let _ = child.wait().await;
-    });
-    Ok(ready)
-}
-
-async fn wait_for_ready_file<F>(
-    progress: &mut F,
-    stderr_path: &Path,
-    child: &mut tokio::process::Child,
-) -> Result<SpawnReady, SpawnError>
-where
-    F: FnMut(&str),
-{
-    let mut tail = StderrTail::new();
-    let deadline = tokio::time::Instant::now() + READY_TIMEOUT;
-    let mut offset = 0usize;
-
-    loop {
-        let content = match tokio::fs::read_to_string(stderr_path).await {
-            Ok(content) => content,
-            Err(e) if e.kind() == io::ErrorKind::NotFound => String::new(),
-            Err(e) => return Err(SpawnError::Io(e)),
-        };
-        if content.len() > offset {
-            for line in content[offset..].lines() {
-                if let Some(rest) = line.strip_prefix(READY_PREFIX) {
-                    let mut parts = rest.splitn(2, '\t');
-                    let worker_name = parts.next().unwrap_or("").to_string();
-                    let socket_str = parts.next().unwrap_or("").to_string();
-                    if worker_name.is_empty() || socket_str.is_empty() {
-                        return Err(SpawnError::WorkerExitedEarly {
-                            stderr_tail: format!("malformed ready line: {line}"),
-                        });
-                    }
-                    let socket_path = PathBuf::from(socket_str);
-                    wait_for_socket(
-                        &socket_path,
-                        deadline,
-                        child,
-                        stderr_path,
-                        &mut tail,
-                        &mut offset,
-                    )
-                    .await?;
-                    return Ok(SpawnReady {
-                        worker_name,
-                        socket_path,
-                    });
-                }
-                tail.push(line);
-                progress(line);
-            }
-            offset = content.len();
-        }
-
-        if tokio::time::Instant::now() >= deadline {
-            return Err(SpawnError::Timeout);
-        }
-        tokio::select! {
-            status = child.wait() => {
-                let _ = status;
-                // Worker は exit 直前に最終 stderr 行を flush することがある。
-                // child.wait() が解決した後に再読みして、原因行を取りこ
-                // ぼさず WorkerExitedEarly に載せる。
-                drain_stderr_into_tail(stderr_path, &mut tail, &mut offset).await;
-                return Err(SpawnError::WorkerExitedEarly {
-                    stderr_tail: tail.into_string(),
-                });
-            }
-            _ = tokio::time::sleep(Duration::from_millis(100)) => {}
-        }
-    }
-}
-
-async fn wait_for_socket(
-    socket_path: &Path,
-    deadline: tokio::time::Instant,
-    child: &mut tokio::process::Child,
-    stderr_path: &Path,
-    tail: &mut StderrTail,
-    offset: &mut usize,
-) -> Result<(), SpawnError> {
-    loop {
-        match tokio::net::UnixStream::connect(socket_path).await {
-            Ok(_) => return Ok(()),
-            Err(e)
-                if e.kind() == io::ErrorKind::NotFound
-                    || e.kind() == io::ErrorKind::ConnectionRefused => {}
-            Err(e) => return Err(SpawnError::Io(e)),
-        }
-        if tokio::time::Instant::now() >= deadline {
-            return Err(SpawnError::Timeout);
-        }
-        tokio::select! {
-            status = child.wait() => {
-                let _ = status;
-                drain_stderr_into_tail(stderr_path, tail, offset).await;
-                return Err(SpawnError::WorkerExitedEarly {
-                    stderr_tail: tail.as_string(),
-                });
-            }
-            _ = tokio::time::sleep(Duration::from_millis(50)) => {}
-        }
-    }
-}
-
-async fn drain_stderr_into_tail(stderr_path: &Path, tail: &mut StderrTail, offset: &mut usize) {
-    let Ok(content) = tokio::fs::read_to_string(stderr_path).await else {
-        return;
-    };
-    if content.len() <= *offset {
-        return;
-    }
-    for line in content[*offset..].lines() {
-        if !line.starts_with(READY_PREFIX) {
-            tail.push(line);
-        }
-    }
-    *offset = content.len();
-}
-
-struct StderrTail {
-    lines: std::collections::VecDeque<String>,
-}
-
-impl StderrTail {
-    fn new() -> Self {
-        Self {
-            lines: std::collections::VecDeque::with_capacity(8),
-        }
-    }
-    fn push(&mut self, line: &str) {
-        if self.lines.len() == 8 {
-            self.lines.pop_front();
-        }
-        self.lines.push_back(line.to_string());
-    }
-    fn as_string(&self) -> String {
-        self.lines.iter().cloned().collect::<Vec<_>>().join(" | ")
-    }
-    fn into_string(self) -> String {
-        self.lines.into_iter().collect::<Vec<_>>().join(" | ")
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use std::ffi::OsString;
-
-    fn base_config() -> WorkerProcessLaunchConfig {
-        WorkerProcessLaunchConfig {
-            runtime_command: WorkerRuntimeCommand::new("/bin/yoi", vec![OsString::from("worker")]),
-            worker_name: "explicit-worker".to_string(),
-            profile: Some("project:companion".to_string()),
-            workspace_root: PathBuf::from("/work/other-project"),
-            cwd: None,
-            resume_from: None,
-        }
-    }
-
-    #[test]
-    fn runtime_args_keep_workspace_worker_and_profile_separate() {
-        assert_eq!(
-            runtime_args(&base_config(), &WorkerProcessLaunchOptions::default()),
-            vec![
-                "--workspace",
-                "/work/other-project",
-                "--worker",
-                "explicit-worker",
-                "--profile",
-                "project:companion",
-            ]
-        );
-    }
-
-    #[test]
-    fn runtime_args_use_session_mode_without_profile_identity_alias() {
-        let mut config = base_config();
-        config.resume_from = Some(Uuid::nil());
-        assert_eq!(
-            runtime_args(&config, &WorkerProcessLaunchOptions::default()),
-            vec![
-                "--workspace",
-                "/work/other-project",
-                "--session",
-                "00000000-0000-0000-0000-000000000000",
-                "--worker",
-                "explicit-worker",
-            ]
-        );
-    }
-
-    #[test]
-    fn runtime_args_include_upper_resolver_extra_args_without_child_cwd() {
-        let mut config = base_config();
-        config.cwd = Some(PathBuf::from("/work/main/.worktree/orchestration/yoi"));
-
-        assert_eq!(
-            runtime_args(
-                &config,
-                &WorkerProcessLaunchOptions::default()
-                    .with_hidden_arg("--ticket-role", "orchestrator"),
-            ),
-            vec![
-                "--workspace",
-                "/work/other-project",
-                "--worker",
-                "explicit-worker",
-                "--profile",
-                "project:companion",
-                "--ticket-role",
-                "orchestrator",
-            ]
-        );
-    }
-}
@@ -1,16 +1,20 @@
-use std::fmt;
+use std::{fmt, path::PathBuf};

-use crate::{BackendRuntimeListTarget, BackendRuntimeTarget, WorkerRuntimeCommand};
+use crate::{
+    BackendApiClient, BackendApiClientError, BackendOrigin, BackendRuntimeListTarget,
+    BackendRuntimeTarget,
+};

 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum TargetKind {
-    Local,
+    /// One-process Standalone authority with no Runtime or Workspace backend.
+    Standalone,
    Backend,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ResolvedTarget {
-    Local,
+    Standalone,
    Backend {
        base_url: String,
        workspace_id: String,
@@ -20,7 +24,7 @@ pub enum ResolvedTarget {
 impl ResolvedTarget {
    pub fn kind(&self) -> TargetKind {
        match self {
-            Self::Local => TargetKind::Local,
+            Self::Standalone => TargetKind::Standalone,
            Self::Backend { .. } => TargetKind::Backend,
        }
    }
@@ -29,31 +33,12 @@ impl ResolvedTarget {
 impl fmt::Display for TargetKind {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
-            Self::Local => f.write_str("local"),
+            Self::Standalone => f.write_str("Standalone"),
            Self::Backend => f.write_str("Backend"),
        }
    }
 }

-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct LocalTarget;
-
-impl LocalTarget {
-    pub fn new() -> Self {
-        Self
-    }
-
-    fn runtime_command(&self) -> Result<WorkerRuntimeCommand, TargetError> {
-        WorkerRuntimeCommand::resolve().map_err(TargetError::local_runtime_command)
-    }
-}
-
-impl Default for LocalTarget {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct BackendTarget {
    pub base_url: String,
@@ -62,11 +47,19 @@ pub struct BackendTarget {

 impl BackendTarget {
    pub fn new(base_url: impl Into<String>, workspace_id: Option<impl Into<String>>) -> Self {
+        let base_url = base_url.into();
+        let base_url = BackendOrigin::parse(&base_url)
+            .map(|origin| origin.to_string())
+            .unwrap_or(base_url);
        Self {
-            base_url: base_url.into(),
+            base_url,
            workspace_id: workspace_id.map(Into::into),
        }
    }
+
+    pub fn authenticated_client(&self) -> Result<BackendApiClient, BackendApiClientError> {
+        BackendApiClient::from_stored_token(&self.base_url)
+    }
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -108,34 +101,31 @@ impl WorkerConnectionSelector {

 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct WorkerSpawn {
-    pub runtime_command: WorkerRuntimeCommand,
+    pub state_dir: PathBuf,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct WorkerByName {
-    pub runtime_command: WorkerRuntimeCommand,
+pub struct StandaloneWorkerListIntent {
+    pub state_dir: PathBuf,
+    pub cwd: PathBuf,
+    pub include_all: bool,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct WorkerResume {
-    pub runtime_command: WorkerRuntimeCommand,
+pub struct StandaloneWorkerResumeIntent {
+    pub state_dir: PathBuf,
+    pub worker_id: String,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum Dashboard {
-    Local {
-        runtime_command: WorkerRuntimeCommand,
-    },
-    Backend {
-        base_url: String,
-        workspace_id: String,
-    },
+pub struct Dashboard {
+    pub base_url: String,
+    pub workspace_id: String,
 }

 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct WorkerList {
-    pub local_runtime_command: Option<WorkerRuntimeCommand>,
-    pub backend_target: Option<BackendRuntimeListTarget>,
+    pub backend_target: BackendRuntimeListTarget,
    pub include_stopped: bool,
 }

@@ -161,12 +151,6 @@ impl TargetError {
            message: format!("invalid {target} target: {}", message.into()),
        }
    }
-
-    fn local_runtime_command(error: std::io::Error) -> Self {
-        Self {
-            message: format!("failed to resolve local Worker runtime command: {error}"),
-        }
-    }
 }

 impl fmt::Display for TargetError {
@@ -183,71 +167,40 @@ pub trait Target: fmt::Debug + Send + Sync {
    /// Resolve the target once for Workspace product-state operations.
    ///
    /// Backend targets must carry an explicit Workspace identity. Callers use
-    /// this value instead of rediscovering Backend/local authority from cwd or
-    /// process configuration after command dispatch.
+    /// this value instead of rediscovering authority from cwd or process
+    /// configuration after command dispatch.
    fn resolve(&self) -> Result<ResolvedTarget, TargetError>;

-    fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError>;
-
-    fn worker_by_name(&self) -> Result<WorkerByName, TargetError>;
-
-    fn resume_worker(&self) -> Result<WorkerResume, TargetError>;
-
-    fn dashboard(&self) -> Result<Dashboard, TargetError>;
-
-    fn list_workers(&self, request: WorkerListRequest) -> Result<WorkerList, TargetError>;
-
-    fn connect_worker(
-        &self,
-        selector: WorkerConnectionSelector,
-    ) -> Result<WorkerConnection, TargetError>;
-}
-
-impl Target for LocalTarget {
-    fn kind(&self) -> TargetKind {
-        TargetKind::Local
-    }
-
-    fn resolve(&self) -> Result<ResolvedTarget, TargetError> {
-        Ok(ResolvedTarget::Local)
-    }
-
    fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError> {
-        Ok(WorkerSpawn {
-            runtime_command: self.runtime_command()?,
-        })
+        Err(TargetError::unsupported("Worker spawn", self.kind()))
    }

-    fn worker_by_name(&self) -> Result<WorkerByName, TargetError> {
-        Ok(WorkerByName {
-            runtime_command: self.runtime_command()?,
-        })
+    fn standalone_worker_list(
+        &self,
+        _include_all: bool,
+    ) -> Result<StandaloneWorkerListIntent, TargetError> {
+        Err(TargetError::unsupported(
+            "standalone Worker listing",
+            self.kind(),
+        ))
    }

-    fn resume_worker(&self) -> Result<WorkerResume, TargetError> {
-        Ok(WorkerResume {
-            runtime_command: self.runtime_command()?,
-        })
+    fn standalone_worker_resume(
+        &self,
+        _worker_id: String,
+    ) -> Result<StandaloneWorkerResumeIntent, TargetError> {
+        Err(TargetError::unsupported(
+            "standalone Worker restore",
+            self.kind(),
+        ))
    }

    fn dashboard(&self) -> Result<Dashboard, TargetError> {
-        Ok(Dashboard::Local {
-            runtime_command: self.runtime_command()?,
-        })
+        Err(TargetError::unsupported("Worker dashboard", self.kind()))
    }

-    fn list_workers(&self, request: WorkerListRequest) -> Result<WorkerList, TargetError> {
-        if request.runtime_id.is_some() {
-            return Err(TargetError::unsupported(
-                "Explicit runtime id for local worker listing",
-                self.kind(),
-            ));
-        }
-        Ok(WorkerList {
-            local_runtime_command: Some(self.runtime_command()?),
-            backend_target: None,
-            include_stopped: request.include_stopped,
-        })
+    fn list_workers(&self, _request: WorkerListRequest) -> Result<WorkerList, TargetError> {
+        Err(TargetError::unsupported("Worker listing", self.kind()))
    }

    fn connect_worker(
@@ -261,6 +214,59 @@ impl Target for LocalTarget {
    }
 }

+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StandaloneTarget {
+    state_dir: PathBuf,
+}
+
+impl StandaloneTarget {
+    #[must_use]
+    pub fn new(state_dir: impl Into<PathBuf>) -> Self {
+        Self {
+            state_dir: state_dir.into(),
+        }
+    }
+}
+
+impl Target for StandaloneTarget {
+    fn kind(&self) -> TargetKind {
+        TargetKind::Standalone
+    }
+
+    fn resolve(&self) -> Result<ResolvedTarget, TargetError> {
+        Ok(ResolvedTarget::Standalone)
+    }
+
+    fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError> {
+        Ok(WorkerSpawn {
+            state_dir: self.state_dir.clone(),
+        })
+    }
+
+    fn standalone_worker_list(
+        &self,
+        include_all: bool,
+    ) -> Result<StandaloneWorkerListIntent, TargetError> {
+        let cwd = std::env::current_dir()
+            .map_err(|error| TargetError::invalid(self.kind(), error.to_string()))?;
+        Ok(StandaloneWorkerListIntent {
+            state_dir: self.state_dir.clone(),
+            cwd,
+            include_all,
+        })
+    }
+
+    fn standalone_worker_resume(
+        &self,
+        worker_id: String,
+    ) -> Result<StandaloneWorkerResumeIntent, TargetError> {
+        Ok(StandaloneWorkerResumeIntent {
+            state_dir: self.state_dir.clone(),
+            worker_id,
+        })
+    }
+}
+
 impl Target for BackendTarget {
    fn kind(&self) -> TargetKind {
        TargetKind::Backend
@@ -279,42 +285,27 @@ impl Target for BackendTarget {
        })
    }

-    fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError> {
-        Err(TargetError::unsupported("Worker spawn", self.kind()))
-    }
-
-    fn worker_by_name(&self) -> Result<WorkerByName, TargetError> {
-        Err(TargetError::unsupported(
-            "Worker name attachment",
-            self.kind(),
-        ))
-    }
-
-    fn resume_worker(&self) -> Result<WorkerResume, TargetError> {
-        Err(TargetError::unsupported("Worker resume", self.kind()))
-    }
-
    fn dashboard(&self) -> Result<Dashboard, TargetError> {
-        match self.resolve()? {
-            ResolvedTarget::Backend {
+        let ResolvedTarget::Backend {
            base_url,
            workspace_id,
-            } => Ok(Dashboard::Backend {
+        } = self.resolve()?
+        else {
+            unreachable!("BackendTarget resolves only Backend authority")
+        };
+        Ok(Dashboard {
            base_url,
            workspace_id,
-            }),
-            ResolvedTarget::Local => unreachable!("BackendTarget cannot resolve as Local"),
-        }
+        })
    }

    fn list_workers(&self, request: WorkerListRequest) -> Result<WorkerList, TargetError> {
        Ok(WorkerList {
-            local_runtime_command: None,
-            backend_target: Some(BackendRuntimeListTarget::new(
+            backend_target: BackendRuntimeListTarget::new(
                self.base_url.clone(),
                self.workspace_id.clone(),
                request.runtime_id,
-            )),
+            ),
            include_stopped: request.include_stopped,
        })
    }
@@ -371,8 +362,34 @@ mod tests {
    }

    #[test]
-    fn local_target_resolves_local_product_state_authority() {
-        assert_eq!(LocalTarget::new().resolve().unwrap(), ResolvedTarget::Local);
+    fn standalone_target_carries_in_process_state_without_runtime_command() {
+        let target = StandaloneTarget::new("/tmp/yoi-standalone-state");
+
+        assert_eq!(target.kind(), TargetKind::Standalone);
+        assert_eq!(target.resolve().unwrap(), ResolvedTarget::Standalone);
+        assert_eq!(
+            target.spawn_worker().unwrap(),
+            WorkerSpawn {
+                state_dir: PathBuf::from("/tmp/yoi-standalone-state"),
+            }
+        );
+    }
+
+    #[test]
+    fn standalone_target_never_exposes_workspace_worker_operations() {
+        let target = StandaloneTarget::new("/tmp/yoi-standalone-state");
+
+        assert_eq!(
+            target
+                .list_workers(WorkerListRequest::new(None))
+                .unwrap_err()
+                .to_string(),
+            "Worker listing is not supported by Standalone target"
+        );
+        assert_eq!(
+            target.dashboard().unwrap_err().to_string(),
+            "Worker dashboard is not supported by Standalone target"
+        );
    }

    #[test]
@@ -381,26 +398,13 @@ mod tests {

        assert_eq!(
            target.dashboard().unwrap(),
-            Dashboard::Backend {
+            Dashboard {
                base_url: "http://127.0.0.1:8787".to_string(),
                workspace_id: "workspace-a".to_string(),
            }
        );
    }

-    #[test]
-    fn backend_target_rejects_dashboard_without_workspace_selection() {
-        let target = BackendTarget::new("http://127.0.0.1:8787", None::<String>);
-
-        assert!(
-            target
-                .dashboard()
-                .unwrap_err()
-                .to_string()
-                .contains("workspace selection is required")
-        );
-    }
-
    #[test]
    fn backend_target_builds_worker_list() {
        let target = BackendTarget::new("http://127.0.0.1:8787", Some("workspace-a"));
@@ -408,26 +412,13 @@ mod tests {
            .list_workers(WorkerListRequest::new(Some("runtime-a".to_string())))
            .unwrap();

+        assert_eq!(workers.backend_target.base_url, "http://127.0.0.1:8787");
        assert_eq!(
-            workers.backend_target.as_ref().unwrap().base_url,
-            "http://127.0.0.1:8787"
-        );
-        assert_eq!(
-            workers
-                .backend_target
-                .as_ref()
-                .unwrap()
-                .workspace_id
-                .as_deref(),
+            workers.backend_target.workspace_id.as_deref(),
            Some("workspace-a")
        );
        assert_eq!(
-            workers
-                .backend_target
-                .as_ref()
-                .unwrap()
-                .runtime_id
-                .as_deref(),
+            workers.backend_target.runtime_id.as_deref(),
            Some("runtime-a")
        );
    }
@@ -446,41 +437,17 @@ mod tests {
    }

    #[test]
-    fn backend_target_rejects_worker_connection_before_workspace_selection() {
-        let target = BackendTarget::new("http://127.0.0.1:8787", None::<String>);
-        let error =
-            match target.connect_worker(WorkerConnectionSelector::new("runtime-a", "worker-b")) {
-                Ok(_) => panic!("unscoped connection must fail"),
-                Err(error) => error,
-            };
+    fn standalone_target_builds_explicit_worker_intents() {
+        let target = StandaloneTarget::new("/tmp/yoi-client-workers");
+        let list = target.standalone_worker_list(true).unwrap();
+        assert_eq!(list.state_dir, PathBuf::from("/tmp/yoi-client-workers"));
+        assert!(list.include_all);
+        assert!(list.cwd.is_absolute());

-        assert!(
-            error
-                .to_string()
-                .contains("workspace selection is required")
-        );
-    }
-
-    #[test]
-    fn backend_target_rejects_local_worker_operations() {
-        let target = BackendTarget::new("http://127.0.0.1:8787", None::<String>);
-        let err = target.spawn_worker().unwrap_err();
-
-        assert_eq!(
-            err.to_string(),
-            "Worker spawn is not supported by Backend target"
-        );
-    }
-
-    #[test]
-    fn local_target_builds_local_worker_list() {
-        let target = LocalTarget::new();
-        let workers = target
-            .list_workers(WorkerListRequest::with_stopped(None))
+        let resume = target
+            .standalone_worker_resume("019d1234-0000-7000-8000-000000000000".to_string())
            .unwrap();
-
-        assert!(workers.local_runtime_command.is_some());
-        assert!(workers.backend_target.is_none());
-        assert!(workers.include_stopped);
+        assert_eq!(resume.state_dir, list.state_dir);
+        assert_eq!(resume.worker_id, "019d1234-0000-7000-8000-000000000000");
    }
 }
@@ -0,0 +1,115 @@
+use async_trait::async_trait;
+use thiserror::Error;
+use tokio::sync::mpsc;
+
+use super::Socket as SocketContract;
+
+const CHANNEL_CAPACITY: usize = 256;
+
+pub struct Socket {
+    outgoing: mpsc::Sender<String>,
+    incoming: mpsc::Receiver<String>,
+}
+
+/// Host-side endpoint paired with an in-process client transport.
+pub struct Peer {
+    incoming: mpsc::Receiver<String>,
+    outgoing: mpsc::Sender<String>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+pub enum SocketError {
+    #[error("in-process Worker protocol transport closed")]
+    Closed,
+}
+
+impl Socket {
+    pub fn pair() -> (Self, Peer) {
+        let (client_tx, peer_rx) = mpsc::channel(CHANNEL_CAPACITY);
+        let (peer_tx, client_rx) = mpsc::channel(CHANNEL_CAPACITY);
+        (
+            Self {
+                outgoing: client_tx,
+                incoming: client_rx,
+            },
+            Peer {
+                incoming: peer_rx,
+                outgoing: peer_tx,
+            },
+        )
+    }
+}
+
+#[async_trait]
+impl SocketContract for Socket {
+    type Error = SocketError;
+
+    async fn send(&mut self, message: String) -> Result<(), Self::Error> {
+        self.outgoing
+            .send(message)
+            .await
+            .map_err(|_| SocketError::Closed)
+    }
+
+    async fn next(&mut self) -> Result<Option<String>, Self::Error> {
+        Ok(self.incoming.recv().await)
+    }
+
+    fn try_next(&mut self) -> Result<Option<String>, Self::Error> {
+        match self.incoming.try_recv() {
+            Ok(message) => Ok(Some(message)),
+            Err(mpsc::error::TryRecvError::Empty | mpsc::error::TryRecvError::Disconnected) => {
+                Ok(None)
+            }
+        }
+    }
+}
+
+impl Peer {
+    pub async fn next(&mut self) -> Option<String> {
+        self.incoming.recv().await
+    }
+
+    pub async fn send(&self, message: String) -> Result<(), String> {
+        self.outgoing.send(message).await.map_err(|error| error.0)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use protocol::stream::{decode_method, encode_event};
+    use protocol::{Event, Method, WorkerStatus};
+
+    use super::Socket;
+    use crate::Client;
+
+    #[tokio::test]
+    async fn pair_carries_typed_protocol_through_generic_client() {
+        let (socket, mut peer) = Socket::pair();
+        let mut client = Client::new(socket);
+
+        client
+            .send(&Method::run_text("hello"))
+            .await
+            .expect("send method");
+        assert!(matches!(
+            peer.next().await.as_deref().map(decode_method),
+            Some(Ok(Method::Run { .. }))
+        ));
+
+        peer.send(
+            encode_event(&Event::Status {
+                status: WorkerStatus::Idle,
+            })
+            .expect("encode event"),
+        )
+        .await
+        .expect("send event");
+        assert!(matches!(
+            client.next_event().await,
+            Ok(Some(Event::Status {
+                status: WorkerStatus::Idle
+            }))
+        ));
+    }
+}
@@ -0,0 +1,22 @@
+use std::error::Error;
+
+use async_trait::async_trait;
+
+pub mod in_process;
+pub mod unix_socket;
+pub mod websocket;
+
+/// Message-oriented transport for one Worker protocol connection.
+///
+/// Implementations own physical framing. `client::Client` owns the typed
+/// Method/Event protocol encoding layered on top of these UTF-8 messages.
+#[async_trait]
+pub trait Socket {
+    type Error: Error + Send + Sync + 'static;
+
+    async fn send(&mut self, message: String) -> Result<(), Self::Error>;
+
+    async fn next(&mut self) -> Result<Option<String>, Self::Error>;
+
+    fn try_next(&mut self) -> Result<Option<String>, Self::Error>;
+}
@@ -0,0 +1,172 @@
+use std::io;
+use std::path::Path;
+
+use async_trait::async_trait;
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::net::UnixStream;
+use tokio::sync::mpsc;
+use tokio::task::JoinHandle;
+
+use super::Socket as SocketContract;
+
+pub struct Socket {
+    writer: tokio::io::WriteHalf<UnixStream>,
+    messages: mpsc::Receiver<io::Result<String>>,
+    reader_task: JoinHandle<()>,
+}
+
+impl Socket {
+    pub async fn connect(path: &Path) -> io::Result<Self> {
+        let stream = UnixStream::connect(path).await?;
+        let (reader, writer) = tokio::io::split(stream);
+        let (message_tx, messages) = mpsc::channel(256);
+        let reader_task = tokio::spawn(async move {
+            let mut lines = BufReader::new(reader).lines();
+            loop {
+                match lines.next_line().await {
+                    Ok(Some(message)) if message.trim().is_empty() => {}
+                    Ok(Some(message)) => {
+                        if message_tx.send(Ok(message)).await.is_err() {
+                            return;
+                        }
+                    }
+                    Ok(None) => return,
+                    Err(error) => {
+                        let _ = message_tx.send(Err(error)).await;
+                        return;
+                    }
+                }
+            }
+        });
+        Ok(Self {
+            writer,
+            messages,
+            reader_task,
+        })
+    }
+}
+
+#[async_trait]
+impl SocketContract for Socket {
+    type Error = io::Error;
+
+    async fn send(&mut self, message: String) -> Result<(), Self::Error> {
+        self.writer.write_all(message.as_bytes()).await?;
+        self.writer.write_all(b"\n").await?;
+        self.writer.flush().await
+    }
+
+    async fn next(&mut self) -> Result<Option<String>, Self::Error> {
+        match self.messages.recv().await {
+            Some(message) => message.map(Some),
+            None => Ok(None),
+        }
+    }
+
+    fn try_next(&mut self) -> Result<Option<String>, Self::Error> {
+        match self.messages.try_recv() {
+            Ok(message) => message.map(Some),
+            Err(mpsc::error::TryRecvError::Empty | mpsc::error::TryRecvError::Disconnected) => {
+                Ok(None)
+            }
+        }
+    }
+}
+
+impl Drop for Socket {
+    fn drop(&mut self) {
+        self.reader_task.abort();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::ErrorKind;
+    use std::time::Duration;
+
+    use protocol::stream::{decode_method, encode_event};
+    use protocol::{Event, Method, WorkerStatus};
+    use tempfile::tempdir;
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::net::UnixListener;
+
+    use super::*;
+    use crate::Client;
+
+    async fn assert_peer_closed(stream: &mut UnixStream, reason: &str) {
+        let mut buf = [0_u8; 1];
+        match tokio::time::timeout(Duration::from_secs(1), stream.read(&mut buf))
+            .await
+            .expect(reason)
+        {
+            Ok(0) => {}
+            Err(error) if error.kind() == ErrorKind::ConnectionReset => {}
+            Ok(n) => panic!("server should observe peer close, read {n} byte(s)"),
+            Err(error) => panic!("server read failed unexpectedly: {error}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn client_receives_events_over_unix_socket() {
+        let socket_dir = tempdir().unwrap();
+        let socket_path = socket_dir.path().join("events.sock");
+        let listener = UnixListener::bind(&socket_path).unwrap();
+        let server = tokio::spawn(async move {
+            let (mut stream, _) = listener.accept().await.unwrap();
+            let event = encode_event(&Event::Status {
+                status: WorkerStatus::Idle,
+            })
+            .unwrap();
+            stream.write_all(event.as_bytes()).await.unwrap();
+            stream.write_all(b"\n").await.unwrap();
+        });
+
+        let mut client = Client::new(Socket::connect(&socket_path).await.unwrap());
+        let event = tokio::time::timeout(Duration::from_secs(1), client.next_event())
+            .await
+            .expect("client should receive event while alive")
+            .expect("transport should succeed");
+        assert!(matches!(
+            event,
+            Some(Event::Status {
+                status: WorkerStatus::Idle
+            })
+        ));
+        server.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn client_sends_methods_over_unix_socket() {
+        let socket_dir = tempdir().unwrap();
+        let socket_path = socket_dir.path().join("send.sock");
+        let listener = UnixListener::bind(&socket_path).unwrap();
+        let server = tokio::spawn(async move {
+            let (reader, _) = listener.accept().await.unwrap();
+            BufReader::new(reader).lines().next_line().await.unwrap()
+        });
+
+        let mut client = Client::new(Socket::connect(&socket_path).await.unwrap());
+        client
+            .send(&Method::run_text("hello"))
+            .await
+            .expect("send method");
+
+        let received = server.await.unwrap().expect("method message");
+        assert!(matches!(decode_method(&received), Ok(Method::Run { .. })));
+    }
+
+    #[tokio::test]
+    async fn dropping_socket_closes_server_connection() {
+        let socket_dir = tempdir().unwrap();
+        let socket_path = socket_dir.path().join("drop.sock");
+        let listener = UnixListener::bind(&socket_path).unwrap();
+        let server = tokio::spawn(async move {
+            let (mut stream, _) = listener.accept().await.unwrap();
+            assert_peer_closed(&mut stream, "dropped socket should close promptly").await;
+        });
+
+        let socket = Socket::connect(&socket_path).await.unwrap();
+        drop(socket);
+        server.await.unwrap();
+    }
+}
@@ -0,0 +1,140 @@
+use async_trait::async_trait;
+use futures::{SinkExt, StreamExt};
+use thiserror::Error;
+use tokio::net::TcpStream;
+use tokio::sync::mpsc;
+use tokio::task::JoinHandle;
+use tokio_tungstenite::tungstenite::http::Request;
+use tokio_tungstenite::tungstenite::{self, Message};
+use tokio_tungstenite::{MaybeTlsStream, WebSocketStream, connect_async};
+
+use super::Socket as SocketContract;
+
+type Writer = futures::stream::SplitSink<WebSocketStream<MaybeTlsStream<TcpStream>>, Message>;
+
+pub struct Socket {
+    writer: Writer,
+    messages: mpsc::Receiver<Result<String, SocketError>>,
+    reader_task: JoinHandle<()>,
+}
+
+#[derive(Debug, Error)]
+pub enum SocketError {
+    #[error("WebSocket transport failed: {0}")]
+    WebSocket(#[from] tungstenite::Error),
+}
+
+impl Socket {
+    pub async fn connect(request: Request<()>) -> Result<Self, SocketError> {
+        let (stream, _) = connect_async(request).await?;
+        let (writer, mut reader) = stream.split();
+        let (message_tx, messages) = mpsc::channel(256);
+        let reader_task = tokio::spawn(async move {
+            loop {
+                match reader.next().await {
+                    Some(Ok(Message::Text(message))) => {
+                        if message_tx.send(Ok(message.to_string())).await.is_err() {
+                            return;
+                        }
+                    }
+                    Some(Ok(Message::Close(_))) | None => return,
+                    Some(Ok(
+                        Message::Binary(_)
+                        | Message::Ping(_)
+                        | Message::Pong(_)
+                        | Message::Frame(_),
+                    )) => {}
+                    Some(Err(error)) => {
+                        let _ = message_tx.send(Err(SocketError::WebSocket(error))).await;
+                        return;
+                    }
+                }
+            }
+        });
+        Ok(Self {
+            writer,
+            messages,
+            reader_task,
+        })
+    }
+}
+
+#[async_trait]
+impl SocketContract for Socket {
+    type Error = SocketError;
+
+    async fn send(&mut self, message: String) -> Result<(), Self::Error> {
+        self.writer.send(Message::Text(message.into())).await?;
+        Ok(())
+    }
+
+    async fn next(&mut self) -> Result<Option<String>, Self::Error> {
+        match self.messages.recv().await {
+            Some(message) => message.map(Some),
+            None => Ok(None),
+        }
+    }
+
+    fn try_next(&mut self) -> Result<Option<String>, Self::Error> {
+        match self.messages.try_recv() {
+            Ok(message) => message.map(Some),
+            Err(mpsc::error::TryRecvError::Empty | mpsc::error::TryRecvError::Disconnected) => {
+                Ok(None)
+            }
+        }
+    }
+}
+
+impl Drop for Socket {
+    fn drop(&mut self) {
+        self.reader_task.abort();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use futures::{SinkExt, StreamExt};
+    use protocol::stream::{decode_method, encode_event};
+    use protocol::{Event, Method, WorkerStatus};
+    use tokio::net::TcpListener;
+    use tokio_tungstenite::accept_async;
+    use tokio_tungstenite::tungstenite::client::IntoClientRequest;
+
+    use super::*;
+    use crate::Client;
+
+    #[tokio::test]
+    async fn carries_typed_protocol_through_generic_client() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let address = listener.local_addr().unwrap();
+        let server = tokio::spawn(async move {
+            let (stream, _) = listener.accept().await.unwrap();
+            let mut socket = accept_async(stream).await.unwrap();
+            let message = socket.next().await.unwrap().unwrap();
+            assert!(matches!(
+                message,
+                Message::Text(ref text)
+                    if matches!(decode_method(text), Ok(Method::Run { .. }))
+            ));
+            let event = encode_event(&Event::Status {
+                status: WorkerStatus::Idle,
+            })
+            .unwrap();
+            socket.send(Message::Text(event.into())).await.unwrap();
+        });
+
+        let request = format!("ws://{address}").into_client_request().unwrap();
+        let mut client = Client::new(Socket::connect(request).await.unwrap());
+        client
+            .send(&Method::run_text("hello"))
+            .await
+            .expect("send method");
+        assert!(matches!(
+            client.next_event().await,
+            Ok(Some(Event::Status {
+                status: WorkerStatus::Idle
+            }))
+        ));
+        server.await.unwrap();
+    }
+}
@@ -1,186 +0,0 @@
-use std::io;
-use std::path::Path;
-
-use protocol::stream::{JsonLineReader, JsonLineWriter};
-use protocol::{Event, Method};
-use tokio::net::UnixStream;
-use tokio::sync::mpsc;
-use tokio::task::JoinHandle;
-
-pub struct WorkerClient {
-    writer: JsonLineWriter<tokio::io::WriteHalf<UnixStream>>,
-    event_rx: mpsc::Receiver<Event>,
-    reader_task: JoinHandle<()>,
-}
-
-impl WorkerClient {
-    pub async fn connect(path: &Path) -> Result<Self, io::Error> {
-        let stream = UnixStream::connect(path).await?;
-        let (reader, writer) = tokio::io::split(stream);
-        let writer = JsonLineWriter::new(writer);
-
-        let (event_tx, event_rx) = mpsc::channel::<Event>(256);
-
-        let reader_task = tokio::spawn(async move {
-            let mut reader = JsonLineReader::new(reader);
-            while let Ok(Some(event)) = reader.next::<Event>().await {
-                if event_tx.send(event).await.is_err() {
-                    break;
-                }
-            }
-        });
-
-        Ok(Self {
-            writer,
-            event_rx,
-            reader_task,
-        })
-    }
-
-    pub async fn send(&mut self, method: &Method) -> Result<(), io::Error> {
-        self.writer.write(method).await
-    }
-
-    pub fn try_next_event(&mut self) -> Option<Event> {
-        self.event_rx.try_recv().ok()
-    }
-
-    pub async fn next_event(&mut self) -> Option<Event> {
-        self.event_rx.recv().await
-    }
-}
-
-impl Drop for WorkerClient {
-    fn drop(&mut self) {
-        self.reader_task.abort();
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use std::io::ErrorKind;
-    use std::time::Duration;
-
-    use protocol::{Segment, WorkerStatus};
-    use tempfile::tempdir;
-    use tokio::io::{AsyncReadExt, AsyncWriteExt};
-    use tokio::net::UnixListener;
-
-    use super::*;
-
-    async fn assert_peer_closed(stream: &mut UnixStream, reason: &str) {
-        let mut buf = [0_u8; 1];
-        match tokio::time::timeout(Duration::from_secs(1), stream.read(&mut buf))
-            .await
-            .expect(reason)
-        {
-            Ok(0) => {}
-            Err(error) if error.kind() == ErrorKind::ConnectionReset => {}
-            Ok(n) => panic!("server should observe peer close, read {n} byte(s)"),
-            Err(error) => panic!("server read failed unexpectedly: {error}"),
-        }
-    }
-
-    #[tokio::test]
-    async fn receives_events_while_client_is_alive() {
-        let socket_dir = tempdir().unwrap();
-        let socket_path = socket_dir.path().join("events.sock");
-        let listener = UnixListener::bind(&socket_path).unwrap();
-        let server = tokio::spawn(async move {
-            let (stream, _) = listener.accept().await.unwrap();
-            let mut writer = JsonLineWriter::new(stream);
-            writer
-                .write(&Event::Status {
-                    status: WorkerStatus::Idle,
-                })
-                .await
-                .unwrap();
-        });
-
-        let mut client = WorkerClient::connect(&socket_path).await.unwrap();
-
-        let event = tokio::time::timeout(Duration::from_secs(1), client.next_event())
-            .await
-            .expect("client should receive event while alive");
-        assert!(matches!(
-            event,
-            Some(Event::Status {
-                status: WorkerStatus::Idle
-            })
-        ));
-        server.await.unwrap();
-    }
-
-    #[tokio::test]
-    async fn send_writes_methods_while_client_is_alive() {
-        let socket_dir = tempdir().unwrap();
-        let socket_path = socket_dir.path().join("send.sock");
-        let listener = UnixListener::bind(&socket_path).unwrap();
-        let server = tokio::spawn(async move {
-            let (stream, _) = listener.accept().await.unwrap();
-            let mut reader = JsonLineReader::new(stream);
-            reader.next::<Method>().await.unwrap()
-        });
-
-        let mut client = WorkerClient::connect(&socket_path).await.unwrap();
-        let method = Method::Run {
-            input: vec![Segment::text("hello")],
-        };
-        client.send(&method).await.unwrap();
-
-        let received = tokio::time::timeout(Duration::from_secs(1), server)
-            .await
-            .expect("server should receive method while client is alive")
-            .unwrap();
-        match received {
-            Some(Method::Run { input }) => assert_eq!(input, vec![Segment::text("hello")]),
-            other => panic!("expected Run method, got {other:?}"),
-        }
-    }
-
-    #[tokio::test]
-    async fn dropping_repeated_clients_closes_server_connections() {
-        let socket_dir = tempdir().unwrap();
-        let socket_path = socket_dir.path().join("drop.sock");
-        let listener = UnixListener::bind(&socket_path).unwrap();
-        let server = tokio::spawn(async move {
-            for _ in 0..16 {
-                let (mut stream, _) = listener.accept().await.unwrap();
-                assert_peer_closed(
-                    &mut stream,
-                    "dropped client should close its socket promptly",
-                )
-                .await;
-            }
-        });
-
-        for _ in 0..16 {
-            let client = WorkerClient::connect(&socket_path).await.unwrap();
-            drop(client);
-        }
-
-        server.await.unwrap();
-    }
-
-    #[tokio::test]
-    async fn dropping_client_aborts_blocked_reader_task() {
-        let socket_dir = tempdir().unwrap();
-        let socket_path = socket_dir.path().join("blocked-reader.sock");
-        let listener = UnixListener::bind(&socket_path).unwrap();
-        let server = tokio::spawn(async move {
-            let (mut stream, _) = listener.accept().await.unwrap();
-            stream.write_all(b"{\"event\"").await.unwrap();
-            assert_peer_closed(
-                &mut stream,
-                "aborting the blocked client reader should close the socket",
-            )
-            .await;
-        });
-
-        let client = WorkerClient::connect(&socket_path).await.unwrap();
-        tokio::task::yield_now().await;
-        drop(client);
-
-        server.await.unwrap();
-    }
-}
@@ -14,7 +14,7 @@ use workspace_api::{
    TICKET_ORCHESTRATION_PLANS_QUERY_PATH, TICKET_RELATIONS_QUERY_PATH,
 };

-use crate::BackendWorkspaceClientError;
+use crate::{BackendApiClient, BackendWorkspaceClientError};

 const DEFAULT_PRODUCT_LIST_LIMIT: usize = 1_000;

@@ -26,7 +26,7 @@ struct BackendWorkerLaunchOptions {
 #[derive(Debug, Deserialize)]
 struct BackendWorkerLaunchRuntime {
    runtime_id: String,
-    can_spawn_worker: bool,
+    worker_creation_available: bool,
    working_directory_required: bool,
 }

@@ -47,9 +47,9 @@ struct BackendWorkspaceOrchestratorResponse {
 /// Construction requires both the selected Backend URL and Workspace identity.
 /// Callers should derive these once from `Target::resolve()` and must not retry
 /// failed requests against repository-local state.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone)]
 pub struct BackendWorkspaceProductClient {
-    base_url: String,
+    api: BackendApiClient,
    workspace_id: String,
 }

@@ -58,22 +58,32 @@ impl BackendWorkspaceProductClient {
        base_url: impl Into<String>,
        workspace_id: impl Into<String>,
    ) -> Result<Self, BackendWorkspaceClientError> {
-        let base_url = base_url.into().trim_end_matches('/').to_string();
-        if base_url.is_empty() {
-            return Err(BackendWorkspaceClientError::InvalidTarget(
-                "Backend base URL must not be empty".into(),
-            ));
-        }
+        let base_url = base_url.into();
+        let api = BackendApiClient::from_stored_token(&base_url)?;
        let workspace_id = workspace_id.into();
        if workspace_id.trim().is_empty() {
            return Err(BackendWorkspaceClientError::InvalidTarget(
                "Backend Workspace identity must not be empty".into(),
            ));
        }
-        Ok(Self {
-            base_url,
-            workspace_id,
-        })
+        Ok(Self { api, workspace_id })
+    }
+
+    #[cfg(test)]
+    fn new_with_access_token(
+        base_url: impl Into<String>,
+        workspace_id: impl Into<String>,
+        access_token: &str,
+    ) -> Result<Self, BackendWorkspaceClientError> {
+        let base_url = base_url.into();
+        let api = BackendApiClient::from_access_token_for_test(&base_url, access_token)?;
+        let workspace_id = workspace_id.into();
+        if workspace_id.trim().is_empty() {
+            return Err(BackendWorkspaceClientError::InvalidTarget(
+                "Backend Workspace identity must not be empty".into(),
+            ));
+        }
+        Ok(Self { api, workspace_id })
    }

    pub fn workspace_id(&self) -> &str {
@@ -261,7 +271,7 @@ impl BackendWorkspaceProductClient {
        let runtime = options
            .runtimes
            .iter()
-            .find(|runtime| runtime.can_spawn_worker && !runtime.working_directory_required)
+            .find(|runtime| runtime.worker_creation_available && !runtime.working_directory_required)
            .ok_or_else(|| {
                BackendWorkspaceClientError::InvalidTarget(
                    "Backend has no spawn-capable Runtime that supports a Workdir-less Intake Worker"
@@ -316,7 +326,7 @@ impl BackendWorkspaceProductClient {
        body: Option<&B>,
    ) -> Result<R, BackendWorkspaceClientError> {
        let response = self.request(method, path, body)?.send()?;
-        let response = ensure_success(response)?;
+        self.api.check_status(response.status())?;
        response.json().map_err(BackendWorkspaceClientError::Http)
    }

@@ -326,7 +336,8 @@ impl BackendWorkspaceProductClient {
        path: &str,
        body: Option<&B>,
    ) -> Result<(), BackendWorkspaceClientError> {
-        ensure_success(self.request(method, path, body)?.send()?)?;
+        let response = self.request(method, path, body)?.send()?;
+        self.api.check_status(response.status())?;
        Ok(())
    }

@@ -336,14 +347,12 @@ impl BackendWorkspaceProductClient {
        path: &str,
        body: Option<&B>,
    ) -> Result<reqwest::blocking::RequestBuilder, BackendWorkspaceClientError> {
-        let client = reqwest::blocking::Client::builder().build()?;
-        let url = format!(
-            "{}/api/w/{}/{}",
-            self.base_url,
+        let path = format!(
+            "/api/w/{}/{}",
            encode_path_segment(&self.workspace_id),
            path.trim_start_matches('/')
        );
-        let request = client.request(method, url);
+        let request = self.api.blocking_request(method, &path)?;
        Ok(match body {
            Some(body) => request.json(body),
            None => request,
@@ -473,8 +482,12 @@ impl TicketBackend for BackendWorkspaceProductClient {
        .map_err(ticket_client_error)
    }

-    fn queue_ready(&self, id: TicketIdOrSlug, _queued_by: &str) -> ticket::Result<()> {
-        self.send_unit::<()>(
+    fn queue_ready(
+        &self,
+        id: TicketIdOrSlug,
+        _queued_by: &str,
+    ) -> ticket::Result<ticket::TicketQueueOutcome> {
+        self.send_json::<(), _>(
            Method::POST,
            &format!(
                "/tickets/{}/workflow/queue",
@@ -584,19 +597,6 @@ fn ticket_client_error(error: BackendWorkspaceClientError) -> TicketError {
    TicketError::Sqlite(format!("Backend request failed: {error}"))
 }

-fn ensure_success(
-    response: reqwest::blocking::Response,
-) -> Result<reqwest::blocking::Response, BackendWorkspaceClientError> {
-    if response.status().is_success() {
-        return Ok(response);
-    }
-    let status = response.status().as_u16();
-    let message = response
-        .text()
-        .unwrap_or_else(|_| "Backend request failed".to_string());
-    Err(BackendWorkspaceClientError::RequestFailed { status, message })
-}
-
 fn ticket_reference(id: &TicketIdOrSlug) -> String {
    match id {
        TicketIdOrSlug::Id(id) => id.to_string(),
@@ -694,24 +694,32 @@ mod tests {
    fn objective_list_uses_workspace_scoped_backend_route() {
        let body = r#"{"workspace_id":"workspace-a","limit":1000,"items":[],"source":"sqlite","diagnostics":[]}"#;
        let (base_url, request, handle) = one_response_server("200 OK", body);
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let response = client.list_objectives(1_000).unwrap();

        assert!(response.items.is_empty());
-        assert!(
-            request
-                .recv()
-                .unwrap()
-                .starts_with("GET /api/w/workspace-a/objectives?limit=1000 ")
-        );
+        let request = request.recv().unwrap();
+        assert!(request.starts_with("GET /api/w/workspace-a/objectives?limit=1000 "));
+        assert!(request.contains("authorization: Bearer test-backend-token\r\n"));
        handle.join().unwrap();
    }

    #[test]
    fn backend_mutation_failure_is_returned_without_local_fallback() {
-        let (base_url, request, handle) = one_response_server("403 Forbidden", "denied");
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let (base_url, request, handle) =
+            one_response_server("403 Forbidden", "test-backend-token");
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let error = client
            .create_objective(&ObjectiveCreateRequest {
@@ -723,6 +731,7 @@ mod tests {
            .unwrap_err();

        assert!(error.to_string().contains("403"));
+        assert!(!error.to_string().contains("test-backend-token"));
        assert!(
            request
                .recv()
@@ -735,7 +744,12 @@ mod tests {
    #[test]
    fn ticket_relation_query_uses_workspace_scoped_backend_route() {
        let (base_url, request, handle) = one_response_server("200 OK", "[]");
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let relations = client
            .query_ticket_relations(
@@ -754,7 +768,12 @@ mod tests {
    #[test]
    fn orchestration_plan_query_uses_workspace_scoped_backend_route() {
        let (base_url, request, handle) = one_response_server("200 OK", "[]");
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let records = TicketBackend::query_orchestration_plan_records(&client, None, None).unwrap();

@@ -773,14 +792,19 @@ mod tests {
        let (base_url, requests, handle) = response_sequence_server(vec![
            (
                "200 OK",
-                r#"{"runtimes":[{"runtime_id":"embedded","can_spawn_worker":true,"working_directory_required":false}]}"#,
+                r#"{"runtimes":[{"runtime_id":"embedded","worker_creation_available":true,"working_directory_required":false}]}"#,
            ),
            (
                "200 OK",
                r#"{"runtime_id":"embedded","worker_id":"worker-1"}"#,
            ),
        ]);
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let status = client.launch_ticket_intake("T-1").unwrap();

@@ -802,7 +826,12 @@ mod tests {
    fn workspace_orchestrator_launch_uses_scoped_backend_route() {
        let body = r#"{"disposition":"created","worker":{"runtime_id":"embedded","worker_id":"worker-2"}}"#;
        let (base_url, request, handle) = one_response_server("200 OK", body);
-        let client = BackendWorkspaceProductClient::new(base_url, "workspace-a").unwrap();
+        let client = BackendWorkspaceProductClient::new_with_access_token(
+            base_url,
+            "workspace-a",
+            "test-backend-token",
+        )
+        .unwrap();

        let status = client.start_workspace_orchestrator().unwrap();

@@ -818,7 +847,12 @@ mod tests {

    #[test]
    fn product_client_requires_workspace_identity() {
-        let error = BackendWorkspaceProductClient::new("http://127.0.0.1:8787", "").unwrap_err();
+        let error = BackendWorkspaceProductClient::new_with_access_token(
+            "http://127.0.0.1:8787",
+            "",
+            "test-backend-token",
+        )
+        .unwrap_err();
        assert!(error.to_string().contains("Workspace identity"));
    }

@@ -101,9 +101,11 @@ pub fn complete_current(
        let utf8_byte_offset = utf16_to_utf8_offset(&source, utf16_offset)?;
        let result = session_environment(snapshot.clone())
            .complete_config(&entrypoint, &source, utf8_byte_offset, explicit)
-            .map_err(|error| JsValue::from_str(&format!("{error:?}")))?
-            .map(|result| WasmCompletionResult {
-                from: result.from,
+            .map_err(|error| JsValue::from_str(&format!("{error:?}")))?;
+        let result = result
+            .map(|result| {
+                Ok::<WasmCompletionResult, JsValue>(WasmCompletionResult {
+                    from: utf8_to_utf16_offset(&source, result.from)?,
                    items: result
                        .items
                        .into_iter()
@@ -114,7 +116,9 @@ pub fn complete_current(
                            priority: item.priority,
                        })
                        .collect(),
-            });
+                })
+            })
+            .transpose()?;
        encode(result)
    })
 }
@@ -177,6 +181,16 @@ fn utf16_to_utf8_offset(source: &str, utf16_offset: usize) -> Result<usize, JsVa
    }
 }

+fn utf8_to_utf16_offset(source: &str, utf8_offset: usize) -> Result<usize, JsValue> {
+    if utf8_offset > source.len() {
+        return Err(JsValue::from_str("UTF-8 offset is outside the source"));
+    }
+    if !source.is_char_boundary(utf8_offset) {
+        return Err(JsValue::from_str("UTF-8 offset splits a character"));
+    }
+    Ok(source[..utf8_offset].encode_utf16().count())
+}
+
 fn decode<T: serde::de::DeserializeOwned>(value: JsValue) -> Result<T, JsValue> {
    from_value(value).map_err(|error| JsValue::from_str(&error.to_string()))
 }
@@ -1203,6 +1203,9 @@ impl SnapshotEnvironment {
        {
            let mut member_source = format!("{WORKSPACE_CONFIG_SCHEMA_GLOBAL}.");
            member_source.push_str(&context.schema_path.join("."));
+            if !context.schema_path.is_empty() && context.from == utf8_byte_offset {
+                member_source.push('.');
+            }
            let mut completion = LanguageService::new(self).complete(
                entrypoint.as_str(),
                &member_source,
@@ -1961,6 +1964,31 @@ mod tests {
                .iter()
                .any(|item| item.label == "default_profile")
        );
+
+        let blank_nested_source = "{ profile = {  } } as WorkspaceConfigSchema";
+        let blank_nested_cursor = blank_nested_source.find("{  }").unwrap() + 2;
+        let blank_nested = environment
+            .complete_config(
+                &path("main.dcdl"),
+                blank_nested_source,
+                blank_nested_cursor,
+                true,
+            )
+            .unwrap()
+            .unwrap();
+        assert_eq!(blank_nested.from, blank_nested_cursor);
+        assert!(
+            blank_nested
+                .items
+                .iter()
+                .any(|item| item.label == "default_profile")
+        );
+        assert!(
+            !blank_nested
+                .items
+                .iter()
+                .any(|item| item.label == "profile")
+        );
    }

    #[test]
@@ -24,7 +24,7 @@ pub fn builtin_flow_source(slug: &str) -> Option<BuiltinFlowSource> {
    match slug {
        CODER_REVIEW_FLOW_SLUG => Some(BuiltinFlowSource {
            slug: CODER_REVIEW_FLOW_SLUG,
-            revision: 3,
+            revision: 4,
            path: "builtin/flows/coder-review.dcdl",
            content: CODER_REVIEW_FLOW_SOURCE,
        }),
@@ -35,7 +35,7 @@ pub fn builtin_flow_source(slug: &str) -> Option<BuiltinFlowSource> {
 pub fn builtin_flow_sources() -> &'static [BuiltinFlowSource] {
    const SOURCES: &[BuiltinFlowSource] = &[BuiltinFlowSource {
        slug: CODER_REVIEW_FLOW_SLUG,
-        revision: 3,
+        revision: 4,
        path: "builtin/flows/coder-review.dcdl",
        content: CODER_REVIEW_FLOW_SOURCE,
    }];
@@ -46,6 +46,30 @@ pub fn builtin_flow_sources() -> &'static [BuiltinFlowSource] {
 mod tests {
    use super::*;

+    #[test]
+    fn coder_review_flow_uses_current_selector_ref_review_contract() {
+        let source = builtin_flow_source(CODER_REVIEW_FLOW_SLUG).expect("coder review Flow");
+        for required in [
+            "OpenMergeRequest",
+            "ShowMergeRequest",
+            "ReviewMergeRequest",
+            "CompleteMergeRequest",
+            "existing Merge Request `selector_from`",
+            "Target-only movement does not invalidate",
+        ] {
+            assert!(source.content.contains(required), "missing {required}");
+        }
+        for stale in [
+            "MergeRequestOpen",
+            "MergeRequestShow",
+            "MergeRequestReview",
+            "MergeRequestComplete",
+            "new immutable revision",
+        ] {
+            assert!(!source.content.contains(stale), "stale contract {stale}");
+        }
+    }
+
    #[test]
    fn every_builtin_flow_compiles_and_matches_catalog_identity() {
        assert!(!builtin_flow_sources().is_empty());
@@ -157,10 +157,28 @@ mod tests {
        }
    }

+    fn grep_request(path: &str, pattern: &str) -> GrepRequest {
+        GrepRequest {
+            pattern: pattern.to_string(),
+            path: FsPath::new(path).unwrap(),
+            glob: None,
+            file_type: None,
+            case_insensitive: false,
+            before_context: 0,
+            after_context: 0,
+            multiline: false,
+            output_mode: GrepOutputMode::Content,
+            limit: 10,
+            offset: 0,
+        }
+    }
+
    #[test]
    fn logical_paths_reject_absolute_parent_and_backslash_forms() {
        assert!(FsPath::new("src/lib.rs").is_ok());
        assert!(FsPath::new("/tmp/file").is_err());
+        assert!(FsPath::new_scoped("/tmp/file").is_ok());
+        assert!(FsPath::new_scoped("/tmp/../secret").is_err());
        assert!(FsPath::new("../file").is_err());
        assert!(FsPath::new("src\\lib.rs").is_err());
    }
@@ -279,4 +297,313 @@ mod tests {
        assert_eq!(grep.matched_files, 2);
        assert!(!grep.output.contains("c.txt"));
    }
+
+    #[test]
+    fn grep_accepts_a_direct_file_without_searching_siblings() {
+        let temp = tempfile::tempdir().unwrap();
+        let selected = temp.path().join("selected.txt");
+        std::fs::write(&selected, "before\nneedle selected\nafter\n").unwrap();
+        std::fs::write(temp.path().join("sibling.txt"), "needle sibling\n").unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        let mut request = grep_request("selected.txt", "needle");
+        request.before_context = 1;
+        request.after_context = 1;
+        let direct = run_grep(&root, selected, request, &readable).unwrap();
+
+        assert_eq!(direct.match_count, 1);
+        assert_eq!(direct.matched_files, 1);
+        assert_eq!(
+            direct.output,
+            concat!(
+                "selected.txt\n",
+                "   1 │ before\n",
+                " > 2 │ needle selected\n",
+                "   3 │ after\n",
+            )
+        );
+        assert!(!direct.output.contains("sibling"));
+
+        let directory = run_grep(
+            &root,
+            root.clone(),
+            GrepRequest {
+                pattern: "needle".to_string(),
+                path: FsPath::root(),
+                glob: None,
+                file_type: None,
+                case_insensitive: false,
+                before_context: 0,
+                after_context: 0,
+                multiline: false,
+                output_mode: GrepOutputMode::Content,
+                limit: 10,
+                offset: 0,
+            },
+            &readable,
+        )
+        .unwrap();
+        assert_eq!(directory.match_count, 2);
+        assert_eq!(directory.matched_files, 2);
+    }
+
+    #[test]
+    fn grep_direct_file_applies_glob_and_type_filters_for_every_output_mode() {
+        let temp = tempfile::tempdir().unwrap();
+        let nested = temp.path().join("nested");
+        std::fs::create_dir(&nested).unwrap();
+        let selected = nested.join("selected.rs");
+        std::fs::write(&selected, "needle one\nneedle two\n").unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        for mode in [
+            GrepOutputMode::Content,
+            GrepOutputMode::FilesWithMatches,
+            GrepOutputMode::Count,
+        ] {
+            for (glob, file_type) in [(Some("other/*.rs"), None), (None, Some("python"))] {
+                let mut request = grep_request("nested/selected.rs", "needle");
+                request.output_mode = mode;
+                request.glob = glob.map(str::to_string);
+                request.file_type = file_type.map(str::to_string);
+
+                let excluded = run_grep(&root, selected.clone(), request, &readable).unwrap();
+                assert_eq!(excluded.output, "", "mode {mode:?}");
+                assert_eq!(excluded.match_count, 0, "mode {mode:?}");
+                assert_eq!(excluded.matched_files, 0, "mode {mode:?}");
+                assert!(!excluded.truncated, "mode {mode:?}");
+            }
+
+            let mut request = grep_request("nested/selected.rs", "needle");
+            request.output_mode = mode;
+            request.glob = Some("nested/*.rs".to_string());
+            request.file_type = Some("rust".to_string());
+            let matched = run_grep(&root, selected.clone(), request, &readable).unwrap();
+
+            match mode {
+                GrepOutputMode::Content => {
+                    assert_eq!(matched.match_count, 2);
+                    assert_eq!(matched.matched_files, 1);
+                    assert!(matched.output.starts_with("nested/selected.rs\n"));
+                    assert!(matched.output.contains("> 1 │ needle one"));
+                    assert!(matched.output.contains("> 2 │ needle two"));
+                }
+                GrepOutputMode::FilesWithMatches => {
+                    assert_eq!(matched.match_count, 1);
+                    assert_eq!(matched.matched_files, 1);
+                    assert_eq!(matched.output, "nested/selected.rs\n");
+                }
+                GrepOutputMode::Count => {
+                    assert_eq!(matched.match_count, 2);
+                    assert_eq!(matched.matched_files, 1);
+                    assert_eq!(matched.output, "nested/selected.rs:2\n");
+                }
+            }
+            assert!(!matched.truncated, "mode {mode:?}");
+        }
+    }
+
+    #[test]
+    fn grep_direct_file_preserves_explicit_hidden_and_gitignored_behavior() {
+        let temp = tempfile::tempdir().unwrap();
+        let hidden = temp.path().join(".hidden.rs");
+        let ignored = temp.path().join("ignored.rs");
+        std::fs::write(&hidden, "needle hidden\n").unwrap();
+        std::fs::write(&ignored, "needle ignored\n").unwrap();
+        std::fs::write(temp.path().join(".gitignore"), "ignored.rs\n").unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        for (path, expected) in [
+            (".hidden.rs", "needle hidden"),
+            ("ignored.rs", "needle ignored"),
+        ] {
+            let result = run_grep(
+                &root,
+                root.join(path),
+                grep_request(path, "needle"),
+                &readable,
+            )
+            .unwrap();
+            assert_eq!(result.match_count, 1, "path {path}");
+            assert!(result.output.contains(expected), "path {path}");
+        }
+    }
+
+    #[test]
+    fn grep_direct_file_preserves_case_multiline_and_bounds() {
+        let temp = tempfile::tempdir().unwrap();
+        let selected = temp.path().join("selected.txt");
+        std::fs::write(&selected, "NEEDLE first\nstart\nfinish\nneedle last\n").unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        let mut case_request = grep_request("selected.txt", "needle");
+        case_request.case_insensitive = true;
+        case_request.offset = 1;
+        case_request.limit = 1;
+        let bounded = run_grep(&root, selected.clone(), case_request, &readable).unwrap();
+        assert_eq!(bounded.match_count, 1);
+        assert!(!bounded.output.contains("NEEDLE first"));
+        assert!(bounded.output.contains("needle last"));
+        assert!(bounded.truncated);
+
+        let mut multiline_request = grep_request("selected.txt", "start\\nfinish");
+        multiline_request.multiline = true;
+        let multiline = run_grep(&root, selected, multiline_request, &readable).unwrap();
+        assert_eq!(multiline.match_count, 1);
+        assert!(multiline.output.contains("start\nfinish"));
+    }
+
+    #[test]
+    fn grep_returns_not_found_for_a_missing_direct_path() {
+        let temp = tempfile::tempdir().unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let missing = root.join("missing.txt");
+        let readable = RootAccess(root.clone());
+
+        let error = run_grep(
+            &root,
+            missing.clone(),
+            grep_request("missing.txt", "needle"),
+            &readable,
+        )
+        .unwrap_err();
+
+        assert!(matches!(error, FsError::NotFound(path) if path == missing));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn grep_keeps_direct_symlink_directory_and_broken_path_guards() {
+        use std::os::unix::fs::symlink;
+
+        let temp = tempfile::tempdir().unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+        std::fs::create_dir(root.join("target-dir")).unwrap();
+        std::fs::write(root.join("target-file.rs"), "needle file\n").unwrap();
+        symlink(root.join("target-file.rs"), root.join("file-link.rs")).unwrap();
+        symlink(root.join("target-dir"), root.join("directory-link")).unwrap();
+        symlink(root.join("missing-target"), root.join("broken-link")).unwrap();
+
+        let request = |path: &str| grep_request(path, "needle");
+
+        let file_result = run_grep(
+            &root,
+            root.join("file-link.rs"),
+            request("file-link.rs"),
+            &readable,
+        )
+        .unwrap();
+        assert_eq!(file_result.match_count, 1);
+        assert!(file_result.output.starts_with("file-link.rs\n"));
+
+        let directory_error = run_grep(
+            &root,
+            root.join("directory-link"),
+            request("directory-link"),
+            &readable,
+        )
+        .unwrap_err();
+        assert!(matches!(
+            directory_error,
+            FsError::SymlinkDirectoryNotTraversed { tool: "Grep", path, .. }
+                if path == root.join("directory-link")
+        ));
+
+        let broken_error = run_grep(
+            &root,
+            root.join("broken-link"),
+            request("broken-link"),
+            &readable,
+        )
+        .unwrap_err();
+        assert!(matches!(
+            broken_error,
+            FsError::BrokenSymlink { path, .. } if path == root.join("broken-link")
+        ));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn grep_rejects_a_direct_special_file_as_invalid_argument() {
+        use std::os::unix::net::UnixListener;
+
+        let temp = tempfile::tempdir().unwrap();
+        let socket = temp.path().join("grep.sock");
+        let _listener = UnixListener::bind(&socket).unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        let error = run_grep(
+            &root,
+            socket,
+            grep_request("grep.sock", "needle"),
+            &readable,
+        )
+        .unwrap_err();
+
+        assert!(matches!(
+            error,
+            FsError::InvalidArgument(message)
+                if message.contains("must be a regular file or directory")
+        ));
+    }
+
+    #[test]
+    fn grep_content_groups_lines_by_file_and_marks_matches() {
+        let temp = tempfile::tempdir().unwrap();
+        std::fs::write(
+            temp.path().join("first.txt"),
+            "before\nneedle one\nafter\nomitted one\nomitted two\nbefore distant\nneedle distant\nafter distant\n",
+        )
+        .unwrap();
+        std::fs::write(temp.path().join("second.txt"), "needle two\n").unwrap();
+        let root = temp.path().canonicalize().unwrap();
+        let readable = RootAccess(root.clone());
+
+        let grep = run_grep(
+            &root,
+            root.clone(),
+            GrepRequest {
+                pattern: "needle".to_string(),
+                path: FsPath::root(),
+                glob: Some("*.txt".to_string()),
+                output_mode: GrepOutputMode::Content,
+                case_insensitive: false,
+                before_context: 1,
+                after_context: 1,
+                multiline: false,
+                file_type: None,
+                limit: 20,
+                offset: 0,
+            },
+            &readable,
+        )
+        .unwrap();
+
+        assert_eq!(grep.match_count, 3);
+        assert_eq!(grep.matched_files, 2);
+        assert_eq!(
+            grep.output,
+            concat!(
+                "first.txt\n",
+                "   1 │ before\n",
+                " > 2 │ needle one\n",
+                "   3 │ after\n",
+                "   …\n",
+                "   6 │ before distant\n",
+                " > 7 │ needle distant\n",
+                "   8 │ after distant\n",
+                "\n",
+                "second.txt\n",
+                " > 1 │ needle two\n",
+            )
+        );
+        assert_eq!(grep.output.matches("first.txt").count(), 1);
+        assert_eq!(grep.output.matches("second.txt").count(), 1);
+    }
 }
@@ -5,7 +5,8 @@ use serde::{Deserialize, Serialize};

 use crate::FsError;

-/// Logical path relative to the bound Workdir root.
+/// Scope-checked filesystem path. Relative paths resolve below the bound
+/// Workdir root; absolute paths require an explicit matching scope rule.
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
 #[serde(transparent)]
 pub struct FsPath(String);
@@ -16,11 +17,30 @@ impl<'de> Deserialize<'de> for FsPath {
        D: serde::Deserializer<'de>,
    {
        let value = String::deserialize(deserializer)?;
-        Self::new(&value).map_err(serde::de::Error::custom)
+        Self::new_scoped(&value).map_err(serde::de::Error::custom)
    }
 }

 impl FsPath {
+    /// Construct a path for a scope-checked operation that may target an
+    /// explicitly granted absolute path outside the provider root.
+    pub fn new_scoped(value: impl Into<String>) -> Result<Self, FsError> {
+        let value = value.into();
+        if !Path::new(&value).is_absolute() {
+            return Self::new(value);
+        }
+        if value.contains('\\') {
+            return Err(FsError::InvalidPath(value));
+        }
+        if Path::new(&value)
+            .components()
+            .any(|component| component == Component::ParentDir)
+        {
+            return Err(FsError::InvalidPath(value));
+        }
+        Ok(Self(value))
+    }
+
    pub fn root() -> Self {
        Self(String::new())
    }
@@ -1,3 +1,5 @@
+use std::collections::BTreeMap;
+use std::fmt::Write as _;
 use std::path::{Path, PathBuf};

 use crate::FsAccessPolicy;
@@ -5,8 +7,8 @@ use grep_regex::RegexMatcherBuilder;
 use grep_searcher::sinks::UTF8 as UTF8Sink;
 use grep_searcher::{BinaryDetection, Searcher, SearcherBuilder, Sink, SinkContext, SinkMatch};
 use ignore::WalkBuilder;
-use ignore::overrides::OverrideBuilder;
-use ignore::types::TypesBuilder;
+use ignore::overrides::{Override, OverrideBuilder};
+use ignore::types::{Types, TypesBuilder};

 use crate::{FsError, GrepOutputMode, GrepRequest, GrepResult, direct_symlink};

@@ -57,20 +59,11 @@ impl GrepReport {
                }
            }
            GrepOutputMode::Content => {
-                for line in &self.lines {
-                    let separator = if line.is_match { ':' } else { '-' };
-                    let path = logical_display(root, &line.path);
-                    if self.show_line_numbers
-                        && let Some(number) = line.line_number
-                    {
-                        output.push_str(&format!(
-                            "{path}{separator}{number}{separator}{}\n",
-                            line.text
+                output.push_str(&render_content_lines(
+                    root,
+                    &self.lines,
+                    self.show_line_numbers,
                ));
-                    } else {
-                        output.push_str(&format!("{path}{separator}{}\n", line.text));
-                    }
-                }
            }
        }
        GrepResult {
@@ -82,6 +75,48 @@ impl GrepReport {
    }
 }

+fn render_content_lines(root: &Path, lines: &[ContentLine], show_line_numbers: bool) -> String {
+    let mut grouped = BTreeMap::<&Path, Vec<&ContentLine>>::new();
+    for line in lines {
+        grouped.entry(&line.path).or_default().push(line);
+    }
+
+    let mut output = String::new();
+    for (file_index, (path, file_lines)) in grouped.into_iter().enumerate() {
+        if file_index > 0 {
+            output.push('\n');
+        }
+        let _ = writeln!(output, "{}", logical_display(root, path));
+
+        let number_width = file_lines
+            .iter()
+            .filter_map(|line| line.line_number)
+            .map(|number| number.to_string().len())
+            .max()
+            .unwrap_or(1);
+        let mut previous_line_end = None;
+        for line in file_lines {
+            if let (Some(previous_end), Some(number)) = (previous_line_end, line.line_number)
+                && number > previous_end
+            {
+                let _ = writeln!(output, "   …");
+            }
+
+            let marker = if line.is_match { '>' } else { ' ' };
+            if show_line_numbers && let Some(number) = line.line_number {
+                let _ = writeln!(output, " {marker} {number:>number_width$} │ {}", line.text);
+            } else {
+                let _ = writeln!(output, " {marker} │ {}", line.text);
+            }
+            previous_line_end = line
+                .line_number
+                .map(|number| number + line.text.split('\n').count() as u64);
+        }
+    }
+
+    output
+}
+
 fn logical_display(root: &Path, path: &Path) -> String {
    path.strip_prefix(root)
        .unwrap_or(path)
@@ -91,6 +126,38 @@ fn logical_display(root: &Path, path: &Path) -> String {

 const DEFAULT_HEAD_LIMIT: usize = 250;

+fn build_overrides(base: &Path, glob: Option<&str>) -> Result<Option<Override>, FsError> {
+    let Some(glob) = glob else {
+        return Ok(None);
+    };
+    let mut builder = OverrideBuilder::new(base);
+    builder
+        .add(glob)
+        .map_err(|error| FsError::InvalidGlob(error.to_string()))?;
+    builder
+        .build()
+        .map(Some)
+        .map_err(|error| FsError::InvalidGlob(error.to_string()))
+}
+
+fn build_types(file_type: Option<&str>) -> Result<Option<Types>, FsError> {
+    let Some(file_type) = file_type else {
+        return Ok(None);
+    };
+    let mut builder = TypesBuilder::new();
+    builder.add_defaults();
+    builder.select(file_type);
+    builder
+        .build()
+        .map(Some)
+        .map_err(|error| FsError::InvalidArgument(format!("invalid type {file_type}: {error}")))
+}
+
+fn direct_file_selected(path: &Path, overrides: Option<&Override>, types: Option<&Types>) -> bool {
+    !overrides.is_some_and(|filter| filter.matched(path, false).is_ignore())
+        && !types.is_some_and(|filter| filter.matched(path, false).is_ignore())
+}
+
 struct GrepParams {
    pattern: String,
    path: Option<PathBuf>,
@@ -186,13 +253,15 @@ pub fn run_grep(
        std::io::ErrorKind::NotFound => FsError::NotFound(base.clone()),
        _ => FsError::io(&base, e),
    })?;
-    if !base_meta.is_dir() {
+    if !base_meta.is_file() && !base_meta.is_dir() {
        return Err(FsError::InvalidArgument(format!(
-            "grep search path is not a directory: {}",
+            "grep search path must be a regular file or directory: {}",
            base.display()
        )));
    }
-    if let Some(info) = symlink.as_ref() {
+    if base_meta.is_dir()
+        && let Some(info) = symlink.as_ref()
+    {
        return Err(FsError::SymlinkDirectoryNotTraversed {
            tool: "Grep",
            path: base.clone(),
@@ -200,32 +269,9 @@ pub fn run_grep(
        });
    }

-    let mut wb = WalkBuilder::new(&base);
-    wb.hidden(true)
-        .git_ignore(true)
-        .git_global(true)
-        .git_exclude(true)
-        .ignore(true)
-        .parents(true)
-        .follow_links(false);
-
-    if let Some(t) = p.file_type.as_deref() {
-        let mut tb = TypesBuilder::new();
-        tb.add_defaults();
-        tb.select(t);
-        let types = tb
-            .build()
-            .map_err(|e| FsError::InvalidArgument(format!("invalid type {t}: {e}")))?;
-        wb.types(types);
-    }
-    if let Some(g) = p.glob.as_deref() {
-        let mut ob = OverrideBuilder::new(&base);
-        ob.add(g).map_err(|e| FsError::InvalidGlob(e.to_string()))?;
-        let ov = ob
-            .build()
-            .map_err(|e| FsError::InvalidGlob(e.to_string()))?;
-        wb.overrides(ov);
-    }
+    let filter_base = if base_meta.is_file() { root } else { &base };
+    let types = build_types(p.file_type.as_deref())?;
+    let overrides = build_overrides(filter_base, p.glob.as_deref())?;

    let mode = p.output_mode.unwrap_or_default();
    let head_limit = p.head_limit.unwrap_or(DEFAULT_HEAD_LIMIT);
@@ -240,74 +286,133 @@ pub fn run_grep(
        lines: Vec::new(),
        truncated: false,
    };
+    let mut matching_files_seen = 0;
+    let mut matches_seen = 0;

-    // Per-mode walker state.
-    let mut matching_files_seen: usize = 0;
-    let mut matches_seen: usize = 0;
+    if base_meta.is_file() {
+        if direct_file_selected(&base, overrides.as_ref(), types.as_ref()) {
+            scan_path(
+                &mut searcher,
+                &matcher,
+                &base,
+                mode,
+                &mut report,
+                &mut matching_files_seen,
+                &mut matches_seen,
+                offset,
+                head_limit,
+            )?;
+        }
+        return Ok(report.into_result(root));
+    }

-    'walker: for entry in wb.build().flatten() {
-        if !entry.file_type().map(|t| t.is_file()).unwrap_or(false) {
+    let mut walker = WalkBuilder::new(&base);
+    walker
+        .hidden(true)
+        .git_ignore(true)
+        .git_global(true)
+        .git_exclude(true)
+        .ignore(true)
+        .parents(true)
+        .follow_links(false);
+    if let Some(types) = types {
+        walker.types(types);
+    }
+    if let Some(overrides) = overrides {
+        walker.overrides(overrides);
+    }
+
+    for entry in walker.build().flatten() {
+        if !entry
+            .file_type()
+            .map(|kind| kind.is_file())
+            .unwrap_or(false)
+        {
            continue;
        }
        let path = entry.path();
        if !access.is_readable(path) {
            continue;
        }
-
-        match mode {
-            GrepOutputMode::FilesWithMatches => {
-                let hit = scan_any_match(&mut searcher, &matcher, path)?;
-                if !hit {
-                    continue;
-                }
-                if matching_files_seen >= offset {
-                    report.files.push(path.to_path_buf());
-                    if report.files.len() >= head_limit {
-                        report.truncated = true;
-                        break 'walker;
-                    }
-                }
-                matching_files_seen += 1;
-            }
-            GrepOutputMode::Count => {
-                let count = scan_count(&mut searcher, &matcher, path)?;
-                if count == 0 {
-                    continue;
-                }
-                if matching_files_seen >= offset {
-                    report.counts.push((path.to_path_buf(), count));
-                    if report.counts.len() >= head_limit {
-                        report.truncated = true;
-                        break 'walker;
-                    }
-                }
-                matching_files_seen += 1;
-            }
-            GrepOutputMode::Content => {
-                let before_count = matches_seen;
-                let mut sink = ContentSink {
-                    path: path.to_path_buf(),
-                    lines: &mut report.lines,
-                    matches_seen: &mut matches_seen,
+        if scan_path(
+            &mut searcher,
+            &matcher,
+            path,
+            mode,
+            &mut report,
+            &mut matching_files_seen,
+            &mut matches_seen,
            offset,
            head_limit,
-                };
-                searcher
-                    .search_path(&matcher, path, &mut sink)
-                    .map_err(|e| FsError::io(path, e))?;
-                // If we hit head_limit during this file, stop walking.
-                if matches_seen >= offset.saturating_add(head_limit) && matches_seen > before_count
-                {
-                    report.truncated = true;
-                    break 'walker;
-                }
-            }
+        )? {
+            break;
        }
    }

    Ok(report.into_result(root))
 }

+#[allow(clippy::too_many_arguments)]
+fn scan_path(
+    searcher: &mut Searcher,
+    matcher: &grep_regex::RegexMatcher,
+    path: &Path,
+    mode: GrepOutputMode,
+    report: &mut GrepReport,
+    matching_files_seen: &mut usize,
+    matches_seen: &mut usize,
+    offset: usize,
+    head_limit: usize,
+) -> Result<bool, FsError> {
+    match mode {
+        GrepOutputMode::FilesWithMatches => {
+            if !scan_any_match(searcher, matcher, path)? {
+                return Ok(false);
+            }
+            if *matching_files_seen >= offset {
+                report.files.push(path.to_path_buf());
+                if report.files.len() >= head_limit {
+                    report.truncated = true;
+                    return Ok(true);
+                }
+            }
+            *matching_files_seen += 1;
+        }
+        GrepOutputMode::Count => {
+            let count = scan_count(searcher, matcher, path)?;
+            if count == 0 {
+                return Ok(false);
+            }
+            if *matching_files_seen >= offset {
+                report.counts.push((path.to_path_buf(), count));
+                if report.counts.len() >= head_limit {
+                    report.truncated = true;
+                    return Ok(true);
+                }
+            }
+            *matching_files_seen += 1;
+        }
+        GrepOutputMode::Content => {
+            let before_count = *matches_seen;
+            let mut sink = ContentSink {
+                path: path.to_path_buf(),
+                lines: &mut report.lines,
+                matches_seen,
+                offset,
+                head_limit,
+            };
+            searcher
+                .search_path(matcher, path, &mut sink)
+                .map_err(|error| FsError::io(path, error))?;
+            if *matches_seen >= offset.saturating_add(head_limit) && *matches_seen > before_count {
+                report.truncated = true;
+                return Ok(true);
+            }
+        }
+    }
+    Ok(false)
+}
+
 fn scan_any_match(
    searcher: &mut Searcher,
    matcher: &grep_regex::RegexMatcher,
@@ -7,6 +7,7 @@ license.workspace = true
 [dependencies]
 arc-swap = "1"
 agen = { workspace = true }
+decodal.workspace = true
 protocol = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
@@ -0,0 +1,318 @@
+use std::collections::BTreeMap;
+
+use decodal::{Data, Engine, ImportLoader, LoadedImport};
+use serde_json::{Map, Number, Value};
+use sha2::{Digest, Sha256};
+
+use crate::profile::ProfileError;
+
+pub const BUILTIN_PROFILE_CATALOG_ID: &str = "builtin-profiles-v2";
+pub const BUILTIN_DEFAULT_PROFILE: &str = "builtin:default";
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct BuiltinProfileImport {
+    pub specifier: &'static str,
+    pub resolved_path: &'static str,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct BuiltinProfileResource {
+    pub selector: Option<&'static str>,
+    pub path: &'static str,
+    pub source: &'static str,
+    pub description: &'static str,
+    pub imports: &'static [BuiltinProfileImport],
+}
+
+const BASE_PATH: &str = "profiles/base.dcdl";
+const BASE_IMPORT: &[BuiltinProfileImport] = &[BuiltinProfileImport {
+    specifier: "./base.dcdl",
+    resolved_path: BASE_PATH,
+}];
+const NO_IMPORTS: &[BuiltinProfileImport] = &[];
+
+pub const BUILTIN_PROFILE_RESOURCES: &[BuiltinProfileResource] = &[
+    BuiltinProfileResource {
+        selector: None,
+        path: BASE_PATH,
+        source: include_str!("../../../resources/profiles/base.dcdl"),
+        description: "Shared built-in Profile defaults.",
+        imports: NO_IMPORTS,
+    },
+    BuiltinProfileResource {
+        selector: Some(BUILTIN_DEFAULT_PROFILE),
+        path: "profiles/default.dcdl",
+        source: include_str!("../../../resources/profiles/default.dcdl"),
+        description: "Standalone Yoi coding profile.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:coder"),
+        path: "profiles/coder.dcdl",
+        source: include_str!("../../../resources/profiles/coder.dcdl"),
+        description: "Ticket implementation with direct Reviewer SubWorkers.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:companion"),
+        path: "profiles/companion.dcdl",
+        source: include_str!("../../../resources/profiles/companion.dcdl"),
+        description: "General assistance with Workspace tools.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:intake"),
+        path: "profiles/intake.dcdl",
+        source: include_str!("../../../resources/profiles/intake.dcdl"),
+        description: "Read-only intake and planning.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:reviewer"),
+        path: "profiles/reviewer.dcdl",
+        source: include_str!("../../../resources/profiles/reviewer.dcdl"),
+        description: "Independent review of a published Merge Request source.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:orchestrator"),
+        path: "profiles/orchestrator.dcdl",
+        source: include_str!("../../../resources/profiles/orchestrator.dcdl"),
+        description: "Workspace orchestration and Worker control.",
+        imports: BASE_IMPORT,
+    },
+    BuiltinProfileResource {
+        selector: Some("builtin:memory-consolidation"),
+        path: "profiles/memory-consolidation.dcdl",
+        source: include_str!("../../../resources/profiles/memory-consolidation.dcdl"),
+        description: "Internal Memory consolidation service.",
+        imports: BASE_IMPORT,
+    },
+];
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BuiltinProfileCatalogSnapshot {
+    pub id: &'static str,
+    pub sources: BTreeMap<String, String>,
+    pub entrypoints: BTreeMap<String, String>,
+    pub imports: BTreeMap<String, String>,
+}
+
+impl BuiltinProfileCatalogSnapshot {
+    pub fn digest(&self) -> String {
+        let mut hasher = Sha256::new();
+        hasher.update(self.id.as_bytes());
+        for (path, source) in &self.sources {
+            hasher.update((path.len() as u64).to_le_bytes());
+            hasher.update(path.as_bytes());
+            hasher.update((source.len() as u64).to_le_bytes());
+            hasher.update(source.as_bytes());
+        }
+        for (selector, path) in &self.entrypoints {
+            hasher.update((selector.len() as u64).to_le_bytes());
+            hasher.update(selector.as_bytes());
+            hasher.update((path.len() as u64).to_le_bytes());
+            hasher.update(path.as_bytes());
+        }
+        for (request, resolved_path) in &self.imports {
+            hasher.update((request.len() as u64).to_le_bytes());
+            hasher.update(request.as_bytes());
+            hasher.update((resolved_path.len() as u64).to_le_bytes());
+            hasher.update(resolved_path.as_bytes());
+        }
+        format!("sha256:{:x}", hasher.finalize())
+    }
+}
+
+pub fn builtin_profile_catalog_snapshot() -> BuiltinProfileCatalogSnapshot {
+    let mut sources = BTreeMap::new();
+    let mut entrypoints = BTreeMap::new();
+    let mut imports = BTreeMap::new();
+
+    for resource in BUILTIN_PROFILE_RESOURCES {
+        sources.insert(resource.path.to_owned(), resource.source.to_owned());
+        for import in resource.imports {
+            imports.insert(
+                format!("{}\0{}", resource.path, import.specifier),
+                import.resolved_path.to_owned(),
+            );
+        }
+        if let Some(selector) = resource.selector {
+            entrypoints.insert(selector.to_owned(), resource.path.to_owned());
+        }
+    }
+
+    BuiltinProfileCatalogSnapshot {
+        id: BUILTIN_PROFILE_CATALOG_ID,
+        sources,
+        entrypoints,
+        imports,
+    }
+}
+
+pub fn builtin_profile_entrypoints() -> impl Iterator<Item = &'static BuiltinProfileResource> {
+    BUILTIN_PROFILE_RESOURCES
+        .iter()
+        .filter(|resource| resource.selector.is_some())
+}
+
+pub(crate) fn resolve_builtin_profile_artifact(
+    selector: &str,
+) -> Result<Option<Value>, ProfileError> {
+    let catalog = builtin_profile_catalog_snapshot();
+    let Some(entrypoint) = catalog.entrypoints.get(selector) else {
+        return Ok(None);
+    };
+    let source = catalog
+        .sources
+        .get(entrypoint)
+        .expect("built-in Profile entrypoint must name a source")
+        .clone();
+    let mut engine = Engine::new(BuiltinProfileImportLoader {
+        sources: catalog.sources,
+    });
+    let module = engine
+        .add_root_source(entrypoint, entrypoint, &source)
+        .map_err(|error| ProfileError::BuiltinProfileEvaluation {
+            selector: selector.to_owned(),
+            message: format!("{error:?}"),
+        })?;
+    let value =
+        engine
+            .eval_module(module)
+            .map_err(|error| ProfileError::BuiltinProfileEvaluation {
+                selector: selector.to_owned(),
+                message: format!("{error:?}"),
+            })?;
+    let data =
+        engine
+            .materialize(&value)
+            .map_err(|error| ProfileError::BuiltinProfileEvaluation {
+                selector: selector.to_owned(),
+                message: format!("{error:?}"),
+            })?;
+    Ok(Some(data_to_json(&data)))
+}
+
+#[derive(Debug)]
+struct BuiltinProfileImportLoader {
+    sources: BTreeMap<String, String>,
+}
+
+impl ImportLoader for BuiltinProfileImportLoader {
+    fn load(
+        &mut self,
+        current_key: Option<&str>,
+        specifier: &str,
+    ) -> decodal::Result<LoadedImport> {
+        let current_key = current_key.ok_or_else(|| {
+            decodal::Diagnostic::new(
+                decodal::DiagnosticKind::Import,
+                decodal::Span::default(),
+                format!("built-in Profile import `{specifier}` has no source context"),
+            )
+        })?;
+        let resolved = resolve_import_path(current_key, specifier).ok_or_else(|| {
+            decodal::Diagnostic::new(
+                decodal::DiagnosticKind::Import,
+                decodal::Span::default(),
+                format!("built-in Profile import `{specifier}` from `{current_key}` is invalid"),
+            )
+        })?;
+        let source = self.sources.get(&resolved).ok_or_else(|| {
+            decodal::Diagnostic::new(
+                decodal::DiagnosticKind::Import,
+                decodal::Span::default(),
+                format!("built-in Profile import `{specifier}` from `{current_key}` was not found"),
+            )
+        })?;
+        Ok(LoadedImport::source(
+            resolved.clone(),
+            resolved,
+            source.clone(),
+        ))
+    }
+}
+
+fn resolve_import_path(current_key: &str, specifier: &str) -> Option<String> {
+    let current_parent = current_key
+        .rsplit_once('/')
+        .map_or("", |(parent, _)| parent);
+    let joined = if let Some(relative) = specifier.strip_prefix("./") {
+        format!("{current_parent}/{relative}")
+    } else {
+        return None;
+    };
+    if joined
+        .split('/')
+        .any(|segment| segment.is_empty() || segment == "." || segment == "..")
+    {
+        return None;
+    }
+    Some(joined)
+}
+
+fn data_to_json(data: &Data) -> Value {
+    match data {
+        Data::Bool(value) => Value::Bool(*value),
+        Data::Int(value) => Value::Number(Number::from(*value)),
+        Data::Float(value) => Number::from_f64(*value)
+            .map(Value::Number)
+            .unwrap_or(Value::Null),
+        Data::String(value) => Value::String(value.clone()),
+        Data::Array(values) => Value::Array(values.iter().map(data_to_json).collect()),
+        Data::Object(fields) => Value::Object(
+            fields
+                .iter()
+                .map(|field| (field.name.clone(), data_to_json(&field.value)))
+                .collect::<Map<_, _>>(),
+        ),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn catalog_has_one_explicit_entrypoint_for_each_builtin_profile() {
+        let catalog = builtin_profile_catalog_snapshot();
+        assert_eq!(catalog.sources.len(), BUILTIN_PROFILE_RESOURCES.len());
+        assert_eq!(catalog.entrypoints.len() + 1, catalog.sources.len());
+        assert_eq!(
+            catalog.entrypoints.get(BUILTIN_DEFAULT_PROFILE),
+            Some(&"profiles/default.dcdl".to_owned())
+        );
+        assert!(catalog.digest().starts_with("sha256:"));
+    }
+
+    #[test]
+    fn default_profile_evaluates_from_the_shared_resource_graph() {
+        let value = resolve_builtin_profile_artifact(BUILTIN_DEFAULT_PROFILE)
+            .expect("evaluate built-in default")
+            .expect("default exists");
+        assert_eq!(value["slug"], "default");
+        assert_eq!(value["feature"]["task"]["enabled"], true);
+        assert_eq!(value["feature"]["sub_worker"]["enabled"], true);
+        assert_eq!(value["feature"]["memory"]["enabled"], false);
+        assert_eq!(value["feature"]["ticket"]["enabled"], false);
+        assert_eq!(value["feature"]["worker"]["enabled"], false);
+        assert_eq!(value["feature"]["manage_workdir"]["enabled"], false);
+    }
+
+    #[test]
+    fn imports_cannot_escape_the_builtin_resource_catalog() {
+        assert_eq!(
+            resolve_import_path("profiles/default.dcdl", "./base.dcdl").as_deref(),
+            Some("profiles/base.dcdl")
+        );
+        assert_eq!(
+            resolve_import_path("profiles/default.dcdl", "../outside.dcdl"),
+            None
+        );
+        assert_eq!(
+            resolve_import_path("profiles/default.dcdl", "/outside.dcdl"),
+            None
+        );
+    }
+}
@@ -92,6 +92,8 @@ pub struct FeatureConfigPartial {
    #[serde(default)]
    pub worker: Option<WorkerFeatureConfigPartial>,
    #[serde(default)]
+    pub workspace_worker_discovery: Option<FeatureFlagConfigPartial>,
+    #[serde(default)]
    pub objective: Option<FeatureFlagConfigPartial>,
    #[serde(default)]
    pub manage_workdir: Option<FeatureFlagConfigPartial>,
@@ -119,6 +121,11 @@ impl FeatureConfigPartial {
            ),
            flow: merge_option(self.flow, other.flow, FeatureFlagConfigPartial::merge),
            worker: merge_option(self.worker, other.worker, WorkerFeatureConfigPartial::merge),
+            workspace_worker_discovery: merge_option(
+                self.workspace_worker_discovery,
+                other.workspace_worker_discovery,
+                FeatureFlagConfigPartial::merge,
+            ),
            objective: merge_option(
                self.objective,
                other.objective,
@@ -265,6 +272,10 @@ impl From<FeatureConfigPartial> for FeatureConfig {
                .worker
                .map(WorkerFeatureConfig::from)
                .unwrap_or_default(),
+            workspace_worker_discovery: value
+                .workspace_worker_discovery
+                .map(FeatureFlagConfig::from)
+                .unwrap_or_default(),
            objective: value
                .objective
                .map(FeatureFlagConfig::from)
@@ -394,6 +405,7 @@ impl From<FeatureConfig> for FeatureConfigPartial {
            sub_worker: Some(value.sub_worker.into()),
            flow: Some(value.flow.into()),
            worker: Some(value.worker.into()),
+            workspace_worker_discovery: Some(value.workspace_worker_discovery.into()),
            objective: Some(value.objective.into()),
            manage_workdir: Some(value.manage_workdir.into()),
            ticket: Some(value.ticket.into()),
@@ -566,15 +578,16 @@ impl WorkerManifestConfig {
        })
    }

-    /// Base config populated with the in-code defaults listed in
-    /// [`crate::defaults`]. Profile and one-file Manifest resolvers start
-    /// from this layer so every per-field default lives at exactly one
-    /// call site (the `defaults` module).
+    /// Base config populated with the in-code per-field defaults listed in
+    /// [`crate::defaults`]. This is not a selectable Profile and does not
+    /// enable a launch capability surface. Profile and one-file Manifest
+    /// resolvers start from this layer so every per-field default lives at
+    /// exactly one call site (the `defaults` module).
    ///
    /// `TryFrom<WorkerManifestConfig>` also reads the same constants as a
    /// belt-and-suspenders fallback, so a manually-constructed config
    /// that skips this layer still resolves to the same values.
-    pub fn builtin_defaults() -> Self {
+    pub fn resolution_defaults() -> Self {
        Self {
            engine: EngineManifestConfig {
                tool_output: ToolOutputLimitsPartial {
@@ -1973,7 +1986,7 @@ enabled = false
 "#,
        )
        .unwrap();
-        let manifest: WorkerManifest = WorkerManifestConfig::builtin_defaults()
+        let manifest: WorkerManifest = WorkerManifestConfig::resolution_defaults()
            .merge(cfg)
            .merge(WorkerManifestConfig {
                worker: WorkerMetaConfig {
@@ -2074,7 +2087,7 @@ enabled = true
 "#,
        )
        .unwrap();
-        let manifest: WorkerManifest = WorkerManifestConfig::builtin_defaults()
+        let manifest: WorkerManifest = WorkerManifestConfig::resolution_defaults()
            .merge(base)
            .merge(upper)
            .merge(WorkerManifestConfig {
@@ -2137,7 +2150,7 @@ permission = "write"

    #[test]
    fn builtin_defaults_populates_worker_limit_defaults() {
-        let cfg = WorkerManifestConfig::builtin_defaults();
+        let cfg = WorkerManifestConfig::resolution_defaults();
        assert_eq!(
            cfg.engine.tool_output.default_max_bytes,
            Some(defaults::TOOL_OUTPUT_MAX_BYTES)
@@ -2172,7 +2185,7 @@ permission = "write"
            },
            ..Default::default()
        };
-        let merged = WorkerManifestConfig::builtin_defaults().merge(overlay);
+        let merged = WorkerManifestConfig::resolution_defaults().merge(overlay);
        let manifest: WorkerManifest = merged.try_into().unwrap();
        assert_eq!(
            manifest.engine.tool_output.default_max_bytes,
@@ -1,3 +1,4 @@
+mod builtin_profile;
 mod config;
 pub mod defaults;
 mod model;
@@ -7,6 +8,11 @@ pub mod plugin;
 mod profile;
 mod scope;

+pub use builtin_profile::{
+    BUILTIN_DEFAULT_PROFILE, BUILTIN_PROFILE_CATALOG_ID, BUILTIN_PROFILE_RESOURCES,
+    BuiltinProfileCatalogSnapshot, BuiltinProfileImport, BuiltinProfileResource,
+    builtin_profile_catalog_snapshot, builtin_profile_entrypoints,
+};
 pub use config::{
    CompactionConfigPartial, EngineManifestConfig, FileUploadLimitsPartial,
    PermissionConfigPartial, ResolveError, SessionConfigPartial, ToolOutputLimitsPartial,
@@ -17,10 +23,11 @@ pub use model::{
 };
 pub use paths::user_profiles_path;
 pub use profile::{
-    ProfileDiscovery, ProfileError, ProfileManifestSnapshot, ProfileMetadata, ProfileRegistry,
-    ProfileRegistryEntry, ProfileRegistrySource, ProfileResolveOptions, ProfileResolver,
-    ProfileSelector, ProfileSource, ResolvedProfile, resolve_profile_artifact,
-    resolve_profile_artifact_value,
+    ProfileDiscovery, ProfileError, ProfileExecutionTarget, ProfileManifestSnapshot,
+    ProfileMetadata, ProfileRegistry, ProfileRegistryEntry, ProfileRegistrySource,
+    ProfileResolveOptions, ProfileResolver, ProfileSelector, ProfileSource, ResolvedProfile,
+    WorkspaceAuthorityRequirement, resolve_profile_artifact, resolve_profile_artifact_value,
+    validate_profile_execution_target,
 };
 pub use protocol::{Permission, ScopeRule};
 pub use scope::{DelegationScope, Scope, ScopeError, SharedScope};
@@ -118,6 +125,10 @@ pub struct FeatureConfig {
    pub flow: FeatureFlagConfig,
    #[serde(default)]
    pub worker: WorkerFeatureConfig,
+    /// Privileged read-only discovery of visible Workspace Workers. Backend
+    /// source proof remains required for every listing operation.
+    #[serde(default)]
+    pub workspace_worker_discovery: FeatureFlagConfig,
    #[serde(default)]
    pub objective: FeatureFlagConfig,
    #[serde(default)]
@@ -142,6 +153,7 @@ impl Default for FeatureConfig {
            sub_worker: FeatureFlagConfig::disabled(),
            flow: FeatureFlagConfig::disabled(),
            worker: WorkerFeatureConfig::disabled(),
+            workspace_worker_discovery: FeatureFlagConfig::disabled(),
            objective: FeatureFlagConfig::disabled(),
            manage_workdir: FeatureFlagConfig::disabled(),
            ticket: TicketFeatureConfig::default(),
@@ -6,9 +6,14 @@
 //! from launch context.

 use serde::{Deserialize, Serialize};
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
+use std::fmt;
 use std::path::{Path, PathBuf};

+use crate::builtin_profile::{
+    BUILTIN_DEFAULT_PROFILE, builtin_profile_catalog_snapshot, builtin_profile_entrypoints,
+    resolve_builtin_profile_artifact,
+};
 use crate::config::{
    CompactionConfigPartial, FeatureConfigPartial, PermissionConfigPartial, SessionConfigPartial,
 };
@@ -23,45 +28,6 @@ use crate::{
 const PROFILE_FORMAT_V1: &str = "yoi.profile.v1";
 const BUILTIN_MODEL_CATALOG: &str = include_str!("../../../resources/models/builtin.toml");

-struct BuiltinProfile {
-    name: &'static str,
-    label: &'static str,
-    description: &'static str,
-}
-
-const BUILTIN_PROFILES: &[BuiltinProfile] = &[
-    BuiltinProfile {
-        name: "companion",
-        label: "builtin:companion",
-        description: "Bundled Companion role profile",
-    },
-    BuiltinProfile {
-        name: "intake",
-        label: "builtin:intake",
-        description: "Bundled Intake role profile",
-    },
-    BuiltinProfile {
-        name: "orchestrator",
-        label: "builtin:orchestrator",
-        description: "Bundled Orchestrator role profile",
-    },
-    BuiltinProfile {
-        name: "coder",
-        label: "builtin:coder",
-        description: "Bundled Coder role profile",
-    },
-    BuiltinProfile {
-        name: "reviewer",
-        label: "builtin:reviewer",
-        description: "Bundled Reviewer role profile",
-    },
-    BuiltinProfile {
-        name: "memory-consolidation",
-        label: "builtin:memory-consolidation",
-        description: "Bundled Memory staging consolidation profile",
-    },
-];
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub enum ProfileRegistrySource {
@@ -159,6 +125,108 @@ impl ProfileSelector {
    }
 }

+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ProfileExecutionTarget {
+    Workspace,
+    Standalone,
+}
+
+impl fmt::Display for ProfileExecutionTarget {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Workspace => formatter.write_str("workspace"),
+            Self::Standalone => formatter.write_str("standalone"),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum WorkspaceAuthorityRequirement {
+    Flow,
+    ManageWorkdir,
+    Memory,
+    MergeRequest,
+    Objective,
+    Orchestration,
+    Plugins,
+    Ticket,
+    Worker,
+}
+
+impl fmt::Display for WorkspaceAuthorityRequirement {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Flow => formatter.write_str("feature.flow"),
+            Self::ManageWorkdir => formatter.write_str("feature.manage_workdir"),
+            Self::Memory => formatter.write_str("feature.memory"),
+            Self::MergeRequest => formatter.write_str("feature.merge_request"),
+            Self::Objective => formatter.write_str("feature.objective"),
+            Self::Orchestration => formatter.write_str("feature.orchestration"),
+            Self::Plugins => formatter.write_str("feature.plugins or plugin packages"),
+            Self::Ticket => formatter.write_str("feature.ticket"),
+            Self::Worker => formatter.write_str("feature.worker"),
+        }
+    }
+}
+
+pub fn validate_profile_execution_target(
+    manifest: &WorkerManifest,
+    target: ProfileExecutionTarget,
+) -> Result<(), ProfileError> {
+    if target == ProfileExecutionTarget::Workspace {
+        return Ok(());
+    }
+
+    let feature = &manifest.feature;
+    let mut requirements = BTreeSet::new();
+    if feature.flow.enabled {
+        requirements.insert(WorkspaceAuthorityRequirement::Flow);
+    }
+    if feature.manage_workdir.enabled {
+        requirements.insert(WorkspaceAuthorityRequirement::ManageWorkdir);
+    }
+    if feature.memory.enabled || feature.memory.staging {
+        requirements.insert(WorkspaceAuthorityRequirement::Memory);
+    }
+    if feature.merge_request.show
+        || feature.merge_request.open
+        || feature.merge_request.review
+        || feature.merge_request.readiness_check
+        || feature.merge_request.complete
+    {
+        requirements.insert(WorkspaceAuthorityRequirement::MergeRequest);
+    }
+    if feature.objective.enabled {
+        requirements.insert(WorkspaceAuthorityRequirement::Objective);
+    }
+    if feature.orchestration.enabled {
+        requirements.insert(WorkspaceAuthorityRequirement::Orchestration);
+    }
+    if feature.plugins.enabled || !manifest.plugins.is_empty() {
+        requirements.insert(WorkspaceAuthorityRequirement::Plugins);
+    }
+    if feature.ticket.enabled
+        || feature.ticket.authoring
+        || feature.ticket.thread
+        || feature.ticket.intake
+        || feature.ticket.workflow
+    {
+        requirements.insert(WorkspaceAuthorityRequirement::Ticket);
+    }
+    if feature.worker.enabled {
+        requirements.insert(WorkspaceAuthorityRequirement::Worker);
+    }
+
+    if requirements.is_empty() {
+        Ok(())
+    } else {
+        Err(ProfileError::UnsupportedExecutionTarget {
+            target,
+            requirements: requirements.into_iter().collect(),
+        })
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(tag = "kind", rename_all = "snake_case")]
 pub enum ProfileSource {
@@ -217,13 +285,14 @@ impl ProfileRegistryEntry {
        source: ProfileRegistrySource,
        name: &'static str,
        label: &'static str,
+        provenance: String,
        description: Option<String>,
    ) -> Self {
        Self {
            source,
            name: name.to_string(),
            path: None,
-            provenance: label.to_string(),
+            provenance,
            description,
            is_default: false,
            artifact: ProfileRegistryArtifact::Builtin { label },
@@ -321,12 +390,16 @@ pub struct ProfileDiscovery {
 }

 impl ProfileDiscovery {
-    pub fn for_cwd(_cwd: &Path) -> Self {
+    pub fn user_settings() -> Self {
        Self {
            user_config: paths::user_profiles_path(),
            project_config: None,
        }
    }
+
+    pub fn for_cwd(_cwd: &Path) -> Self {
+        Self::user_settings()
+    }
    pub fn with_sources(user_config: Option<PathBuf>, project_config: Option<PathBuf>) -> Self {
        Self {
            user_config,
@@ -412,15 +485,22 @@ impl ProfileResolver {
                options,
            ),
            ProfileSelector::Named { .. } | ProfileSelector::Default => {
-                let cwd = std::env::current_dir().map_err(|source| ProfileError::CommandIo {
-                    path: PathBuf::from("."),
-                    source,
-                })?;
-                let registry = ProfileDiscovery::for_cwd(&cwd).discover()?;
+                let registry = ProfileDiscovery::user_settings().discover()?;
                self.resolve_from_registry(selector, &registry, options)
            }
        }
    }
+
+    pub fn resolve_for_target(
+        &self,
+        selector: &ProfileSelector,
+        options: ProfileResolveOptions,
+        target: ProfileExecutionTarget,
+    ) -> Result<ResolvedProfile, ProfileError> {
+        let resolved = self.resolve(selector, options)?;
+        validate_profile_execution_target(&resolved.manifest, target)?;
+        Ok(resolved)
+    }
    /// Resolve a registry/default selector against an already-discovered
    /// registry. Callers such as SubWorkerSpawn use this to bind discovery to the
    /// Worker's cwd instead of the process current directory.
@@ -503,7 +583,7 @@ impl ProfileResolver {
                .as_deref()
                .unwrap_or_else(|| Path::new(".")),
        )?;
-        let raw_artifact = builtin_profile_artifact(label).ok_or_else(|| {
+        let raw_artifact = resolve_builtin_profile_artifact(label)?.ok_or_else(|| {
            ProfileError::InvalidProfile(format!("unknown builtin profile artifact `{label}`"))
        })?;
        resolve_profile_value(
@@ -565,7 +645,8 @@ fn resolve_profile_value(
        memory: profile.memory.map(Into::into),
        skills: profile.skills,
    };
-    let config = WorkerManifestConfig::builtin_defaults().merge(config.resolve_paths(profile_dir));
+    let config =
+        WorkerManifestConfig::resolution_defaults().merge(config.resolve_paths(profile_dir));
    let mut manifest = WorkerManifest::try_from(config).map_err(ProfileError::ManifestResolve)?;
    manifest.profile = Some(ProfileManifestSnapshot {
        source: source.clone(),
@@ -759,14 +840,30 @@ fn load_profile_registry_file(
 }

 fn add_builtin_profiles(registry: &mut ProfileRegistry) {
-    for profile in BUILTIN_PROFILES {
+    let catalog = builtin_profile_catalog_snapshot();
+    let digest = catalog.digest();
+    for profile in builtin_profile_entrypoints() {
+        let label = profile
+            .selector
+            .expect("built-in Profile entrypoint must have a selector");
+        let name = label
+            .strip_prefix("builtin:")
+            .expect("built-in Profile selector must be source-qualified");
        registry.push_entry(ProfileRegistryEntry::embedded(
            ProfileRegistrySource::Builtin,
-            profile.name,
-            profile.label,
+            name,
+            label,
+            format!("{}#{digest}", profile.path),
            Some(profile.description.into()),
        ));
    }
+    registry.set_default(ProfileDefault {
+        source: Some(ProfileRegistrySource::Builtin),
+        name: BUILTIN_DEFAULT_PROFILE
+            .strip_prefix("builtin:")
+            .expect("built-in default selector must be source-qualified")
+            .to_owned(),
+    });
 }

 fn parse_profile_ref(raw: &str) -> (Option<ProfileRegistrySource>, String) {
@@ -804,201 +901,6 @@ fn read_profile_artifact_file(path: &Path) -> Result<serde_json::Value, ProfileE
    }
 }

-fn builtin_profile_artifact(label: &str) -> Option<serde_json::Value> {
-    let mut value = builtin_base_profile_artifact();
-    match label {
-        "builtin:companion" | "companion" => {
-            apply_role_profile(
-                &mut value,
-                "companion",
-                "Workspace companion profile.",
-                "workspace_write",
-                true,
-                true,
-                true,
-                true,
-            );
-            Some(value)
-        }
-        "builtin:intake" | "intake" => {
-            apply_role_profile(
-                &mut value,
-                "intake",
-                "Ticket intake profile.",
-                "workspace_write",
-                true,
-                true,
-                true,
-                false,
-            );
-            Some(value)
-        }
-        "builtin:orchestrator" | "orchestrator" => {
-            apply_role_profile(
-                &mut value,
-                "orchestrator",
-                "Ticket orchestrator profile.",
-                "workspace_write",
-                true,
-                true,
-                true,
-                false,
-            );
-            Some(value)
-        }
-        "builtin:coder" | "coder" => {
-            apply_role_profile(
-                &mut value,
-                "coder",
-                "Ticket implementation coder profile.",
-                "workspace_write",
-                true,
-                true,
-                true,
-                true,
-            );
-            Some(value)
-        }
-        "builtin:reviewer" | "reviewer" => {
-            apply_role_profile(
-                &mut value,
-                "reviewer",
-                "Ticket review profile.",
-                "workspace_read",
-                true,
-                true,
-                true,
-                false,
-            );
-            Some(value)
-        }
-        "builtin:memory-consolidation" | "memory-consolidation" => {
-            value["slug"] = serde_json::Value::String("memory-consolidation".to_string());
-            value["description"] =
-                serde_json::Value::String("Memory staging consolidation profile.".to_string());
-            value["feature"]["task"] = serde_json::json!({ "enabled": false });
-            value["feature"]["memory"] = serde_json::json!({ "enabled": true, "staging": true });
-            value["feature"]["web"] = serde_json::json!({ "enabled": false });
-            value["feature"]["sub_worker"] = serde_json::json!({ "enabled": false });
-            value["feature"]["objective"] = serde_json::json!({ "enabled": false });
-            value["feature"]["ticket"] = serde_json::json!({ "enabled": false, "thread": false });
-            Some(value)
-        }
-        _ => None,
-    }
-}
-
-fn builtin_base_profile_artifact() -> serde_json::Value {
-    serde_json::json!({
-        "slug": "default",
-        "description": "Default Yoi coding profile.",
-        "model": { "ref": "codex-oauth/gpt-5.5" },
-        "session": { "record_event_trace": true },
-        "engine": { "reasoning": "high" },
-        "compaction": {
-            "kind": "tokens",
-            "threshold": 240000,
-            "request_threshold": 270000,
-            "worker_context_max_tokens": 100000
-        },
-        "feature": {
-            "task": { "enabled": true },
-            "memory": { "enabled": true },
-            "web": { "enabled": true },
-            "image": { "enabled": true },
-            "sub_worker": { "enabled": true },
-            "worker": { "enabled": false },
-            "objective": { "enabled": true },
-            "ticket": { "enabled": true, "authoring": true, "thread": true }
-        },
-        "memory": {
-            "extract_threshold": 50000,
-            "consolidation_threshold_files": 5,
-            "consolidation_threshold_bytes": 50000
-        },
-        "web": {
-            "enabled": true,
-            "search": {
-                "provider": "brave",
-                "api_key_secret": "web/brave/default"
-            }
-        }
-    })
-}
-
-#[allow(clippy::too_many_arguments)]
-fn apply_role_profile(
-    value: &mut serde_json::Value,
-    slug: &str,
-    description: &str,
-    _scope: &str,
-    task: bool,
-    memory: bool,
-    web: bool,
-    sub_worker: bool,
-) {
-    value["slug"] = serde_json::Value::String(slug.to_string());
-    value["description"] = serde_json::Value::String(description.to_string());
-    value["feature"]["task"] = serde_json::json!({ "enabled": task });
-    value["feature"]["memory"] = serde_json::json!({ "enabled": memory });
-    value["feature"]["web"] = serde_json::json!({ "enabled": web });
-    value["feature"]["image"] = serde_json::json!({ "enabled": true });
-    value["feature"]["sub_worker"] = serde_json::json!({ "enabled": sub_worker });
-    value["feature"]["flow"] = serde_json::json!({ "enabled": slug == "coder" });
-    value["feature"]["worker"] = serde_json::json!({
-        "enabled": matches!(slug, "companion" | "orchestrator"),
-        "direct_spawn": slug != "orchestrator"
-    });
-    value["feature"]["manage_workdir"] = serde_json::json!({
-        "enabled": matches!(slug, "companion" | "orchestrator")
-    });
-    value["feature"]["orchestration"] = serde_json::json!({ "enabled": slug == "orchestrator" });
-    let ticket = match slug {
-        "companion" => serde_json::json!({ "enabled": true, "authoring": true, "thread": true }),
-        "intake" => {
-            serde_json::json!({ "enabled": true, "authoring": true, "thread": true, "intake": true })
-        }
-        "orchestrator" => {
-            serde_json::json!({ "enabled": true, "thread": true, "workflow": true })
-        }
-        "coder" => serde_json::json!({ "enabled": true, "thread": true }),
-        "reviewer" => serde_json::json!({ "enabled": true, "thread": true }),
-        _ => serde_json::json!({ "enabled": true, "authoring": true, "thread": true }),
-    };
-    value["feature"]["ticket"] = ticket;
-    let merge_request = match slug {
-        "coder" => serde_json::json!({
-            "show": true,
-            "open": true,
-            "review": false,
-            "readiness_check": false,
-            "complete": false
-        }),
-        "reviewer" => serde_json::json!({
-            "show": true,
-            "open": false,
-            "review": true,
-            "readiness_check": false,
-            "complete": false
-        }),
-        "orchestrator" => serde_json::json!({
-            "show": true,
-            "open": false,
-            "review": false,
-            "readiness_check": true,
-            "complete": true
-        }),
-        _ => serde_json::json!({
-            "show": false,
-            "open": false,
-            "review": false,
-            "readiness_check": false,
-            "complete": false
-        }),
-    };
-    value["feature"]["merge_request"] = merge_request;
-}
-
 fn reject_manifest_shaped_profile(value: &serde_json::Value) -> Result<(), ProfileError> {
    let Some(map) = value.as_object() else {
        return Err(ProfileError::InvalidProfile(
@@ -1288,6 +1190,13 @@ pub enum ProfileError {
        #[source]
        source: toml::de::Error,
    },
+    #[error("failed to evaluate built-in Profile `{selector}`: {message}")]
+    BuiltinProfileEvaluation { selector: String, message: String },
+    #[error("Profile requires unsupported {target} launch authorities: {requirements:?}")]
+    UnsupportedExecutionTarget {
+        target: ProfileExecutionTarget,
+        requirements: Vec<WorkspaceAuthorityRequirement>,
+    },
    #[error("no default profile is configured")]
    NoDefaultProfile,
    #[error("profile resolution requires an explicit runtime Worker name")]
@@ -1341,18 +1250,21 @@ mod tests {
        );
    }
    #[test]
-    fn builtin_profiles_do_not_define_an_implicit_default() {
+    fn builtin_default_is_explicit_registry_authority() {
        let registry = ProfileDiscovery::with_sources(None, None)
            .discover()
            .unwrap();
-        assert!(matches!(
-            registry.default_entry(),
-            Err(ProfileError::NoDefaultProfile)
-        ));
-        assert!(matches!(
-            registry.select(&ProfileSelector::Default),
-            Err(ProfileError::NoDefaultProfile)
-        ));
+        let default = registry.default_entry().unwrap();
+        assert_eq!(default.source, ProfileRegistrySource::Builtin);
+        assert_eq!(default.name, "default");
+        assert_eq!(default.qualified_name(), BUILTIN_DEFAULT_PROFILE);
+        assert!(default.is_default);
+        assert!(
+            default
+                .provenance
+                .starts_with("profiles/default.dcdl#sha256:")
+        );
+        assert_eq!(registry.select(&ProfileSelector::Default).unwrap(), default);
    }
    #[test]
    fn builtin_role_profiles_are_registered_and_resolve() {
@@ -1408,7 +1320,108 @@ mod tests {
    }

    #[test]
-    fn builtin_companion_can_manage_workdirs() {
+    fn builtin_default_resolves_as_a_standalone_local_capability_profile() {
+        let tmp = TempDir::new().unwrap();
+        let resolved = ProfileResolver::new()
+            .with_workspace_base(tmp.path())
+            .resolve_for_target(
+                &ProfileSelector::source_named(ProfileRegistrySource::Builtin, "default"),
+                ProfileResolveOptions::with_worker_name("standalone-worker"),
+                ProfileExecutionTarget::Standalone,
+            )
+            .unwrap();
+
+        assert!(matches!(
+            &resolved.source,
+            ProfileSource::Registry {
+                source: ProfileRegistrySource::Builtin,
+                name,
+                path: None,
+                provenance: Some(provenance),
+                ..
+            } if name == "default" && provenance.starts_with("profiles/default.dcdl#sha256:")
+        ));
+        assert!(resolved.manifest.feature.task.enabled);
+        assert!(resolved.manifest.feature.web.enabled);
+        assert!(resolved.manifest.feature.image.enabled);
+        assert!(resolved.manifest.feature.sub_worker.enabled);
+        assert!(resolved.manifest.scope.allow.iter().any(|rule| {
+            rule.permission == protocol::Permission::Write && rule.target == tmp.path()
+        }));
+        assert!(resolved.manifest.delegation_scope.allow.iter().any(|rule| {
+            rule.permission == protocol::Permission::Write && rule.target == tmp.path()
+        }));
+        assert!(!resolved.manifest.feature.memory.enabled);
+        assert!(!resolved.manifest.feature.ticket.enabled);
+        assert!(!resolved.manifest.feature.objective.enabled);
+        assert!(!resolved.manifest.feature.flow.enabled);
+        assert!(!resolved.manifest.feature.worker.enabled);
+        assert!(!resolved.manifest.feature.manage_workdir.enabled);
+        assert!(!resolved.manifest.feature.plugins.enabled);
+        assert!(resolved.manifest.plugins.is_empty());
+    }
+
+    #[test]
+    fn standalone_rejects_profiles_that_require_workspace_authority() {
+        let tmp = TempDir::new().unwrap();
+        let error = ProfileResolver::new()
+            .with_workspace_base(tmp.path())
+            .resolve_for_target(
+                &ProfileSelector::source_named(ProfileRegistrySource::Builtin, "coder"),
+                ProfileResolveOptions::with_worker_name("standalone-worker"),
+                ProfileExecutionTarget::Standalone,
+            )
+            .unwrap_err();
+        let diagnostic = error.to_string();
+
+        let ProfileError::UnsupportedExecutionTarget {
+            target,
+            requirements,
+        } = error
+        else {
+            panic!("unexpected error: {error}");
+        };
+        assert_eq!(target, ProfileExecutionTarget::Standalone);
+        assert!(requirements.contains(&WorkspaceAuthorityRequirement::Memory));
+        assert!(requirements.contains(&WorkspaceAuthorityRequirement::MergeRequest));
+        assert!(requirements.contains(&WorkspaceAuthorityRequirement::Ticket));
+        assert!(!diagnostic.contains(tmp.path().to_string_lossy().as_ref()));
+    }
+
+    #[test]
+    fn repository_markers_do_not_change_builtin_profile_authority() {
+        let tmp = TempDir::new().unwrap();
+        let nested = tmp.path().join("repository/nested");
+        std::fs::create_dir_all(&nested).unwrap();
+        std::fs::create_dir_all(tmp.path().join("repository/.yoi")).unwrap();
+        std::fs::write(
+            tmp.path().join("repository/.yoi/profiles.toml"),
+            "default = { source = 'project', name = 'shadow' }\n",
+        )
+        .unwrap();
+
+        let discovery = ProfileDiscovery::for_cwd(&nested);
+        assert_eq!(discovery.user_config, paths::user_profiles_path());
+        assert!(discovery.project_config.is_none());
+    }
+
+    #[test]
+    fn builtin_coder_uses_sub_worker_control_without_worker_control() {
+        let tmp = TempDir::new().unwrap();
+        let resolved = ProfileResolver::new()
+            .with_workspace_base(tmp.path())
+            .resolve(
+                &ProfileSelector::source_named(ProfileRegistrySource::Builtin, "coder"),
+                ProfileResolveOptions::with_worker_name("coder-worker"),
+            )
+            .unwrap();
+
+        assert!(resolved.manifest.feature.sub_worker.enabled);
+        assert!(!resolved.manifest.feature.worker.enabled);
+    }
+
+    #[test]
+    fn builtin_companion_combines_runtime_and_sub_worker_control_with_discovery() {
        let tmp = TempDir::new().unwrap();
        let resolved = ProfileResolver::new()
            .with_workspace_base(tmp.path())
@@ -1419,6 +1432,32 @@ mod tests {
            .unwrap();

        assert!(resolved.manifest.feature.manage_workdir.enabled);
+        assert!(resolved.manifest.feature.sub_worker.enabled);
+        assert!(resolved.manifest.feature.worker.enabled);
+        assert!(!resolved.manifest.feature.worker.direct_spawn);
+        assert!(resolved.manifest.feature.workspace_worker_discovery.enabled);
+    }
+
+    #[test]
+    fn builtin_orchestrator_keeps_cleanup_tool_providers_enabled() {
+        let tmp = TempDir::new().unwrap();
+        let resolved = ProfileResolver::new()
+            .with_workspace_base(tmp.path())
+            .resolve(
+                &ProfileSelector::source_named(ProfileRegistrySource::Builtin, "orchestrator"),
+                ProfileResolveOptions::with_worker_name("orchestrator-worker"),
+            )
+            .unwrap();
+        let feature = resolved.manifest.feature;
+
+        assert!(feature.worker.enabled);
+        assert!(!feature.worker.direct_spawn);
+        assert!(feature.manage_workdir.enabled);
+        assert!(feature.merge_request.show);
+        assert!(feature.merge_request.readiness_check);
+        assert!(feature.merge_request.complete);
+        assert!(!feature.merge_request.open);
+        assert!(!feature.merge_request.review);
    }

    #[test]
@@ -9,7 +9,7 @@
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};

-use crate::schema::{EvidenceKind, SourceEvidenceRef, SourceRef};
+use crate::schema::{EvidenceKind, EvidenceOrigin, SourceEvidenceRef, SourceRef};

 /// Current flat staging schema version.
 pub const STAGING_SCHEMA_VERSION: u32 = 2;
@@ -80,6 +80,8 @@ pub struct StagingEvidence {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub entry_range: Option<[u64; 2]>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub origin: Option<EvidenceOrigin>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub excerpt: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub summary: Option<String>,
@@ -159,6 +161,7 @@ mod tests {
            id: "E001".into(),
            kind: EvidenceKind::new(EvidenceKind::MESSAGE),
            entry_range: Some([10, 12]),
+            origin: None,
            excerpt: Some("extract candidate taxonomy".into()),
            summary: Some("User and assistant discussed staging kinds".into()),
        };
@@ -67,6 +67,40 @@ impl EvidenceKind {
    }
 }

+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum EvidenceOriginKind {
+    HumanInput,
+    WorkerInput,
+    FlowInstruction,
+    BackendInstruction,
+    ModelOutput,
+    ToolOutput,
+    DerivedSummary,
+    LegacyUnknown,
+}
+
+/// Bounded origin snapshot attached to extraction evidence. This is audit
+/// metadata only and cannot authorize Workspace operations.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+pub struct EvidenceOrigin {
+    pub kind: EvidenceOriginKind,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub account_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub workspace_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub runtime_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub worker_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub flow_selector: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub flow_definition_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub flow_definition_revision: Option<u64>,
+}
+
 /// Host-resolved source/evidence metadata for an individual staging claim.
 ///
 /// This deliberately stores only bounded anchor metadata: stable ids, entry
@@ -86,6 +120,9 @@ pub struct SourceEvidenceRef {
    /// Host-assigned evidence id within the referenced evidence set.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub evidence_id: Option<String>,
+    /// Trusted typed origin snapshot for this logical evidence entry.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub origin: Option<EvidenceOrigin>,
    /// Extensible evidence kind tag.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub evidence_kind: Option<EvidenceKind>,
@@ -10,7 +10,10 @@ mod decision;
 mod request;
 mod summary;

-pub use common::{EvidenceKind, Frontmatter, SourceEvidenceRef, SourceRef, split_frontmatter};
+pub use common::{
+    EvidenceKind, EvidenceOrigin, EvidenceOriginKind, Frontmatter, SourceEvidenceRef, SourceRef,
+    split_frontmatter,
+};
 pub use decision::{DecisionFrontmatter, DecisionStatus};
 pub use request::RequestFrontmatter;
 pub use summary::SummaryFrontmatter;
@@ -416,7 +416,7 @@ impl MergeRequestStore {
        let conflict:bool=t.query_row("SELECT EXISTS(SELECT 1 FROM merge_request_ticket_relations rel JOIN merge_requests mr ON mr.workspace_id=rel.workspace_id AND mr.merge_request_id=rel.merge_request_id WHERE rel.workspace_id=?1 AND rel.ticket_id=?2 AND mr.state='open')",params![i.auth.workspace_id,i.ticket_id],|r|r.get(0))?;
        if conflict {
            return Err(MergeRequestError::Conflict(
-                "Ticket already has an open Merge Request".into(),
+                "Ticket already has an open Merge Request; use ShowMergeRequest and advance the existing selector_from with a normal non-force push instead of opening a replacement Merge Request or adding a revision".into(),
            ));
        }
        let now = i.now.to_rfc3339();
@@ -575,12 +575,16 @@ impl MergeRequestStore {
            ));
        };
        if subject != i.current_subject_ref {
+            let reason = format!(
+                "selector_from moved from requested subject {subject} to current subject {}; fresh review of the exact current source ref is required",
+                i.current_subject_ref
+            );
            let e = ReviewCancelledEvent {
                event_id: Uuid::now_v7().to_string(),
                sequence: next_seq(&t, &ws, &mr)?,
                request_event_id: req,
                subject_ref: subject,
-                reason: "selector_from moved before submission".into(),
+                reason,
                created_at: i.now,
            };
            insert_event(&t, &ws, &mr, "review_cancelled", &e, i.now, None)?;
@@ -667,9 +671,27 @@ impl MergeRequestStore {
        }
        match (&i.current_subject_ref, &review) {
            (None, _) => b.push("selector_from could not be resolved".into()),
-            (Some(_), None) => b.push("current source ref has no valid review".into()),
-            (_, Some(r)) if r.decision == ReviewDecision::RequestChanges => {
-                b.push("current source ref requests changes".into())
+            (Some(subject_ref), None) => {
+                let previous_review_subject = mr.thread.iter().rev().find_map(|event| match event {
+                    MergeRequestThreadEvent::ReviewRequested(value) => {
+                        Some(value.subject_ref.as_str())
+                    }
+                    MergeRequestThreadEvent::Review(value) => Some(value.subject_ref.as_str()),
+                    _ => None,
+                });
+                match previous_review_subject.filter(|previous| *previous != subject_ref) {
+                    Some(previous) => b.push(format!(
+                        "selector_from moved from reviewed/requested subject {previous} to current subject {subject_ref}; request a fresh review for this exact source ref (selector_to movement alone does not invalidate source approval)"
+                    )),
+                    None => b.push(format!(
+                        "current source ref {subject_ref} has no valid review; request a fresh review for this exact source ref"
+                    )),
+                }
+            }
+            (Some(subject_ref), Some(r)) if r.decision == ReviewDecision::RequestChanges => {
+                b.push(format!(
+                    "current source ref {subject_ref} requests changes; advance the existing selector_from with a normal non-force push, then request a fresh review for the exact new source ref"
+                ))
            }
            _ => {}
        }
@@ -181,16 +181,85 @@ fn source_move_cancels_submission_and_old_approval_is_reusable_when_source_retur
        .is_err()
    );
    let mr = s.get("W", "T").unwrap();
+    let cancellation = mr.thread.iter().find_map(|event| match event {
+        MergeRequestThreadEvent::ReviewCancelled(value) => Some(value),
+        _ => None,
+    });
    assert!(
-        mr.thread
-            .iter()
-            .any(|e| matches!(e, MergeRequestThreadEvent::ReviewCancelled(_)))
+        cancellation
+            .as_ref()
+            .is_some_and(|value| value.reason.contains("selector_from moved")
+                && value.reason.contains("fresh review"))
    );
    assert_eq!(
        mr.effective_review("source-a").map(|r| &r.event_id),
        Some(&approved.event_id)
    );
 }
+#[test]
+fn same_selector_source_advancement_requires_fresh_review_and_preserves_target_only_approval() {
+    let (_d, s) = fixture();
+    open(&s);
+    let first = approve(&s, "source-1", "one");
+
+    let stale = s
+        .readiness(ReadinessCheck {
+            ticket_id: "T".into(),
+            current_subject_ref: Some("source-2".into()),
+            auth: auth(),
+        })
+        .unwrap();
+    assert!(!stale.ready);
+    assert!(stale.review.is_none());
+    assert!(stale.blockers.iter().any(|blocker| {
+        blocker.contains("selector_from moved from reviewed/requested subject source-1")
+            && blocker.contains("current subject source-2")
+            && blocker.contains("fresh review")
+    }));
+    assert_eq!(
+        s.get("W", "T")
+            .unwrap()
+            .effective_review("source-1")
+            .map(|review| &review.event_id),
+        Some(&first.event_id)
+    );
+
+    let second = approve(&s, "source-2", "two");
+    let ready = s
+        .readiness(ReadinessCheck {
+            ticket_id: "T".into(),
+            current_subject_ref: Some("source-2".into()),
+            auth: auth(),
+        })
+        .unwrap();
+    assert!(ready.ready);
+    assert_eq!(
+        ready.review.as_ref().map(|review| &review.event_id),
+        Some(&second.event_id)
+    );
+
+    // The target can move from target-1 to target-2 without changing selector_from
+    // or invalidating the exact-source approval. Completion consumes refreshed
+    // integration evidence for the current target pair.
+    let merged = s
+        .complete(CompleteMergeRequest {
+            operation_id: "target-moved".into(),
+            ticket_id: "T".into(),
+            current_subject_ref: "source-2".into(),
+            target_ref_before: "target-2".into(),
+            target_ref_after: "integrated-target-2".into(),
+            approval_event_id: second.event_id,
+            strategy: MergeStrategy::FastForward,
+            resolution: ConflictResolution::None,
+            auth: auth(),
+            now: at(5),
+        })
+        .unwrap();
+    assert_eq!(merged.approved_source_ref, "source-2");
+    assert_eq!(merged.target_ref_before, "target-2");
+    assert_eq!(merged.target_ref_after, "integrated-target-2");
+}
+
 #[test]
 fn review_revocation_invalidates_readiness() {
    let (_d, s) = fixture();
@@ -14,6 +14,7 @@ json-schema = ["dep:schemars"]
 schemars = { workspace = true, optional = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+sha2.workspace = true
 tokio = { workspace = true, features = ["io-util"], optional = true }
 ts-rs = { version = "12.0.1", optional = true }
-uuid = { workspace = true, features = ["serde"] }
+uuid = { workspace = true, features = ["serde", "v7"] }
@@ -0,0 +1,132 @@
+use std::{fmt, str::FromStr};
+
+use serde::{Deserialize, Deserializer, Serialize, Serializer, de};
+use sha2::{Digest, Sha256};
+use uuid::{Uuid, Version};
+
+/// Stable Worker identity independent of its current Runtime placement or
+/// conversation Session.
+///
+/// Workspace authority allocates this ID for managed Workers. A standalone
+/// Worker store allocates it locally when no Workspace authority is present.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct WorkerId(Uuid);
+
+impl WorkerId {
+    pub fn now_v7() -> Self {
+        Self(Uuid::now_v7())
+    }
+
+    /// Converts a legacy Runtime-local numeric id into a syntactically valid
+    /// migration-only UUIDv7 value. New Worker allocation must use `now_v7`.
+    pub fn from_legacy_u64(value: u64) -> Self {
+        let mut bytes = [0_u8; 16];
+        bytes[8..].copy_from_slice(&value.to_be_bytes());
+        bytes[6] = 0x70;
+        bytes[8] = (bytes[8] & 0x3f) | 0x80;
+        Self(Uuid::from_bytes(bytes))
+    }
+
+    pub fn from_legacy_binding(workspace_id: &str, runtime_id: &str, value: u64) -> Self {
+        let mut hasher = Sha256::new();
+        hasher.update(b"yoi.workspace-worker-id.v1\0");
+        hasher.update(workspace_id.as_bytes());
+        hasher.update([0]);
+        hasher.update(runtime_id.as_bytes());
+        hasher.update([0]);
+        hasher.update(value.to_be_bytes());
+        let digest = hasher.finalize();
+        let mut bytes = [0_u8; 16];
+        bytes.copy_from_slice(&digest[..16]);
+        // Migrated ids sort before normally allocated UUIDv7 values while retaining
+        // deterministic collision-resistant payload bits.
+        bytes[..6].fill(0);
+        bytes[6] = (bytes[6] & 0x0f) | 0x70;
+        bytes[8] = (bytes[8] & 0x3f) | 0x80;
+        Self(Uuid::from_bytes(bytes))
+    }
+
+    pub fn parse(value: &str) -> Option<Self> {
+        let value = Uuid::parse_str(value).ok()?;
+        (value.get_version() == Some(Version::SortRand)).then_some(Self(value))
+    }
+
+    pub const fn as_uuid(self) -> Uuid {
+        self.0
+    }
+
+    #[must_use]
+    pub fn short(self) -> String {
+        let simple = self.0.simple().to_string();
+        simple[simple.len() - 12..].to_string()
+    }
+}
+
+impl fmt::Display for WorkerId {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(formatter)
+    }
+}
+
+impl FromStr for WorkerId {
+    type Err = WorkerIdParseError;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        Self::parse(value).ok_or(WorkerIdParseError)
+    }
+}
+
+impl Serialize for WorkerId {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for WorkerId {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let value = String::deserialize(deserializer)?;
+        Self::parse(&value).ok_or_else(|| de::Error::custom("Worker id must be a UUIDv7"))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct WorkerIdParseError;
+
+impl fmt::Display for WorkerIdParseError {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter.write_str("Worker id must be a UUIDv7")
+    }
+}
+
+impl std::error::Error for WorkerIdParseError {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn worker_id_accepts_only_uuid_v7() {
+        let worker_id = WorkerId::now_v7();
+        assert_eq!(WorkerId::parse(&worker_id.to_string()), Some(worker_id));
+        assert!(WorkerId::parse("30").is_none());
+        assert!(WorkerId::parse(&Uuid::nil().to_string()).is_none());
+    }
+
+    #[test]
+    fn legacy_worker_id_mapping_is_stable() {
+        assert_eq!(
+            WorkerId::from_legacy_binding("workspace", "runtime", 42),
+            WorkerId::from_legacy_binding("workspace", "runtime", 42)
+        );
+        assert_ne!(
+            WorkerId::from_legacy_binding("workspace", "runtime", 42),
+            WorkerId::from_legacy_binding("workspace", "runtime", 43)
+        );
+    }
+}
@@ -1,3 +1,4 @@
+pub mod identity;
 #[cfg(feature = "stream")]
 pub mod stream;
 pub mod subscription;
@@ -8,6 +9,8 @@ use std::path::PathBuf;

 use serde::{Deserialize, Serialize};

+pub use identity::{WorkerId, WorkerIdParseError};
+
 fn default_true() -> bool {
    true
 }
@@ -190,6 +193,106 @@ impl WorkerEvent {
 /// variants — emits an alert and inserts a `[unknown input segment]`
 /// placeholder into the LLM context so neither user nor LLM is blind to
 /// the dropped intent.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+#[serde(rename_all = "snake_case")]
+pub enum PasteArtifactMediaType {
+    TextPlainUtf8,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+#[serde(rename_all = "snake_case")]
+pub enum PasteArtifactAvailability {
+    Available,
+    Unavailable,
+    IntegrityFailed,
+}
+
+impl PasteArtifactMediaType {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::TextPlainUtf8 => "text/plain; charset=utf-8",
+        }
+    }
+}
+
+impl PasteArtifactAvailability {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Available => "available",
+            Self::Unavailable => "unavailable",
+            Self::IntegrityFailed => "integrity_failed",
+        }
+    }
+}
+
+/// Session-owned reference to a large pasted-input artifact.
+///
+/// The reference contains only bounded integrity and provenance metadata. The
+/// artifact body remains in session storage and is available to the model only
+/// through the scoped paste-artifact tools installed by Worker.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+pub struct PasteArtifactRef {
+    pub artifact_id: String,
+    pub created_at_ms: u64,
+    pub media_type: PasteArtifactMediaType,
+    /// Availability observed when this immutable reference was committed.
+    /// Reads revalidate storage and integrity rather than trusting this field.
+    pub availability: PasteArtifactAvailability,
+    pub byte_len: u64,
+    pub char_count: u64,
+    pub line_count: u64,
+    pub sha256: String,
+    pub source_entry_id: String,
+}
+
+/// Availability recorded for an uploaded client-local file.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+#[serde(rename_all = "snake_case")]
+pub enum UploadedFileAvailability {
+    Available,
+    Unavailable,
+    IntegrityFailed,
+}
+
+impl UploadedFileAvailability {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Available => "available",
+            Self::Unavailable => "unavailable",
+            Self::IntegrityFailed => "integrity_failed",
+        }
+    }
+}
+
+/// Session-owned immutable reference to a client-local uploaded file.
+///
+/// Upload transports return an unbound reference. Worker fills
+/// `source_entry_id` immediately before the containing user input is committed;
+/// committed Session Log and public snapshot records therefore always retain
+/// the durable source-entry identity without storing the file body.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+pub struct UploadedFileRef {
+    pub artifact_id: String,
+    pub file_name: String,
+    pub media_type: String,
+    pub created_at_ms: u64,
+    pub availability: UploadedFileAvailability,
+    pub byte_len: u64,
+    pub sha256: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub source_entry_id: Option<String>,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
 #[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
@@ -207,6 +310,14 @@ pub enum Segment {
        lines: u32,
        content: String,
    },
+    /// Internal reference produced when Worker stores a large `Paste` before
+    /// committing input. Clients may receive this in history/event projections;
+    /// the body is intentionally absent.
+    PasteArtifact { artifact: PasteArtifactRef },
+    /// Client-local file uploaded into the owning Worker session before submit.
+    /// The Session Log stores only this immutable reference, never file bytes or
+    /// the client's local path.
+    UploadedFile { file: UploadedFileRef },
    /// `@<path>` file-system reference. Worker resolves readable files to
    /// `[File: <path>]` attachments and readable normal directories to shallow
    /// `[Dir: <path>]` listings; the flattened user text keeps the literal
@@ -247,6 +358,35 @@ impl Segment {
            match seg {
                Segment::Text { content } => out.push_str(content),
                Segment::Paste { content, .. } => out.push_str(content),
+                Segment::PasteArtifact { artifact } => {
+                    use std::fmt::Write as _;
+                    let _ = write!(
+                        out,
+                        "[Large paste stored as artifact {}: {} bytes, {} chars, {} lines, {}, {}, created at {} ms, sha256 {}; use SearchInputArtifact and ReadInputArtifact to inspect it]",
+                        artifact.artifact_id,
+                        artifact.byte_len,
+                        artifact.char_count,
+                        artifact.line_count,
+                        artifact.media_type.as_str(),
+                        artifact.availability.as_str(),
+                        artifact.created_at_ms,
+                        artifact.sha256
+                    );
+                }
+                Segment::UploadedFile { file } => {
+                    use std::fmt::Write as _;
+                    let _ = write!(
+                        out,
+                        "[Attached file {} stored as input artifact {}: {} bytes, {}, {}, created at {} ms, sha256 {}; use SearchInputArtifact and ReadInputArtifact for supported text content]",
+                        file.file_name,
+                        file.artifact_id,
+                        file.byte_len,
+                        file.media_type,
+                        file.availability.as_str(),
+                        file.created_at_ms,
+                        file.sha256
+                    );
+                }
                Segment::FileRef { path } => {
                    out.push('@');
                    out.push_str(path);
@@ -281,11 +421,44 @@ impl Method {
 /// Presentation category for an Internal Worker exposed through its parent's
 /// protocol stream. Internal Workers never become independently addressable
 /// protocol subjects.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
 #[serde(rename_all = "snake_case")]
 pub enum InternalWorkerKind {
    SubWorker,
+    Service { kind: String },
+}
+
+/// Stable parent-owned lifecycle for one compaction run.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+pub struct CompactionLifecycle {
+    pub schema_version: u32,
+    pub compaction_id: String,
+    pub revision: u64,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub internal_worker: Option<InternalWorkerRef>,
+    pub state: CompactionLifecycleState,
+    /// Milliseconds since the Unix epoch.
+    pub started_at_ms: u64,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub ended_at_ms: Option<u64>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub summary: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub new_segment_id: Option<String>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(rename_all = "snake_case")]
+pub enum CompactionLifecycleState {
+    Running,
+    Done,
+    Failed,
+    Interrupted,
 }

 /// Stable presentation identity for one parent-owned Internal Worker session.
@@ -307,8 +480,7 @@ pub struct InternalWorkerRef {
 pub struct InternalWorkerSnapshot {
    pub worker: InternalWorkerRef,
    pub revision: u64,
-    #[cfg_attr(feature = "typescript", ts(type = "Array<unknown>"))]
-    pub entries: Vec<serde_json::Value>,
+    pub session: SessionSnapshot,
    #[serde(default)]
    pub status: WorkerStatus,
    #[serde(default, skip_serializing_if = "Option::is_none")]
@@ -319,12 +491,126 @@ pub struct InternalWorkerSnapshot {
    pub internal_workers: Vec<InternalWorkerSnapshot>,
 }

+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(rename_all = "snake_case")]
+pub enum ToolResultDisposition {
+    #[default]
+    Success,
+    Error,
+    Interrupted,
+    Cancelled,
+    OutcomeUnknown,
+}
+
+/// Canonical, storage-independent projection of committed session history.
+///
+/// Worker protocols expose this DTO instead of append-log records. New
+/// storage variants can therefore be added without teaching every client how
+/// to replay the durable log format.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+pub struct SessionSnapshot {
+    pub entries: Vec<SessionSnapshotEntry>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(rename_all = "snake_case")]
+pub enum SessionEntryProvenance {
+    HumanInput,
+    WorkerInput,
+    FlowInstruction,
+    BackendInstruction,
+    ModelOutput,
+    ToolOutput,
+    DerivedSummary,
+    LegacyUnknown,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+pub struct SessionSnapshotEntry {
+    /// Stable identity from durable history metadata, or a deterministic
+    /// identity derived from the legacy segment and log position.
+    pub entry_id: String,
+    /// Timestamp copied from the durable log record that commits this entry.
+    pub timestamp: u64,
+    pub provenance: SessionEntryProvenance,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub derived_from: Vec<String>,
+    #[serde(flatten)]
+    pub data: SessionSnapshotEntryData,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum SessionSnapshotEntryData {
+    UserInput {
+        segments: Vec<Segment>,
+    },
+    Message {
+        role: SessionMessageRole,
+        content: Vec<SessionContentPart>,
+    },
+    ToolCall {
+        call_id: String,
+        name: String,
+        arguments: String,
+    },
+    ToolResult {
+        call_id: String,
+        summary: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        content: Option<String>,
+        is_error: bool,
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        attachments: Vec<SessionToolAttachment>,
+    },
+    SystemItem {
+        item_kind: String,
+        content: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        #[cfg_attr(feature = "typescript", ts(type = "unknown"))]
+        data: Option<serde_json::Value>,
+    },
+    RunError {
+        message: String,
+    },
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(rename_all = "snake_case")]
+pub enum SessionMessageRole {
+    User,
+    Assistant,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum SessionContentPart {
+    Text { text: String },
+    Refusal { refusal: String },
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+pub struct SessionToolAttachment {
+    pub media_type: String,
+    /// Base64-encoded durable attachment body. Public snapshots preserve the
+    /// committed multimodal value instead of replacing it with placeholder text.
+    pub data_base64: String,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
 #[serde(tag = "event", content = "data", rename_all = "snake_case")]
 pub enum Event {
    /// A user input message was accepted, persisted as
-    /// `LogEntry::UserInput`, and is about to start a new turn.
+    /// `LogEntry::AnnotatedUserInput`, and is about to start a new turn.
    /// Broadcast to every subscribed client so TUI / GUI instances show
    /// the same user line that reconnect snapshots would replay from
    /// history; clients must not synthesize a separate pending/fake
@@ -345,7 +631,7 @@ pub enum Event {
    /// of parsing free-text prefixes like `[Notification] …` or
    /// `[File: …]`.
    ///
-    /// One event per `LogEntry::SystemItem` commit. Disk-side and
+    /// One event per `LogEntry::AnnotatedSystemItem` commit. Disk-side and
    /// wire-side are 1:1.
    SystemItem {
        #[cfg_attr(feature = "typescript", ts(type = "unknown"))]
@@ -468,6 +754,8 @@ pub enum Event {
        /// summary-only, or when the result was pruned.
        #[serde(default, skip_serializing_if = "Option::is_none")]
        output: Option<String>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        disposition: Option<ToolResultDisposition>,
        #[serde(default)]
        is_error: bool,
    },
@@ -508,8 +796,7 @@ pub enum Event {
    /// role-specific entry events (`SegmentRotated` / `SystemItem`) —
    /// there is no generic "every committed entry" broadcast.
    Snapshot {
-        #[cfg_attr(feature = "typescript", ts(type = "Array<unknown>"))]
-        entries: Vec<serde_json::Value>,
+        session: SessionSnapshot,
        greeting: Greeting,
        #[serde(default)]
        status: WorkerStatus,
@@ -542,14 +829,10 @@ pub enum Event {
    /// Server-side segment log rotated to a fresh `SegmentStart`.
    ///
    /// Fires on compaction and on auto-fork when the store head drifts
-    /// from the live writer's cached head. Clients drop their derived
-    /// view and reseed from `entry.history` exactly the way they would
-    /// from a connect-time `Snapshot`.
-    ///
-    /// Payload is the JSON form of `session_store::LogEntry::SegmentStart`.
+    /// A compaction/fork has replaced the authoritative segment. Clients drop
+    /// their derived view and reseed from the canonical committed snapshot.
    SegmentRotated {
-        #[cfg_attr(feature = "typescript", ts(type = "unknown"))]
-        entry: serde_json::Value,
+        session: SessionSnapshot,
    },
    /// Current Worker controller status. Broadcast on every controller-level
    /// transition and included in `History` snapshots for late attach.
@@ -576,11 +859,10 @@ pub enum Event {
        head_entries: usize,
        targets: Vec<RewindTarget>,
    },
-    /// A rewind has truncated the authoritative session. `entries` is the
-    /// retained session-log prefix clients should use to reseed display state.
+    /// A rewind has truncated the authoritative session. `session` is the
+    /// retained canonical snapshot clients should use to reseed display state.
    RewindApplied {
-        #[cfg_attr(feature = "typescript", ts(type = "Array<unknown>"))]
-        entries: Vec<serde_json::Value>,
+        session: SessionSnapshot,
        input: Vec<Segment>,
        summary: RewindSummary,
    },
@@ -607,23 +889,18 @@ pub enum Event {
    /// This is not part of LLM history or prompt context; clients may display it
    /// briefly as operational status.
    MemoryWorker(MemoryWorkerEvent),
-    /// Worker has started compacting the current session.
-    ///
-    /// Fired immediately before a compaction run. Success is signalled by
-    /// `CompactDone` (with the new `SegmentId`); failure by `CompactFailed`.
-    /// Broadcast to all clients; not replayed to late subscribers.
-    CompactStart,
-    /// Compaction completed and the session was rotated.
-    ///
-    /// `new_segment_id` is the UUID of the freshly created session that
-    /// replaced the old history.
-    CompactDone {
-        #[cfg_attr(feature = "typescript", ts(type = "string"))]
-        new_segment_id: uuid::Uuid,
+    /// Worker has started compacting the current session, or bound the run to its
+    /// observable Internal Worker. Revisions upsert one stable lifecycle item.
+    CompactStart {
+        lifecycle: CompactionLifecycle,
    },
-    /// Compaction failed. The session is unchanged.
+    /// Compaction completed and the session was rotated.
+    CompactDone {
+        lifecycle: CompactionLifecycle,
+    },
+    /// Compaction failed or was cancelled. The session is unchanged.
    CompactFailed {
-        error: String,
+        lifecycle: CompactionLifecycle,
    },
    Shutdown,
 }
@@ -895,6 +1172,7 @@ pub enum WorkerStatus {
    Idle,
    Running,
    Paused,
+    Stopped,
 }

 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
@@ -1061,6 +1339,55 @@ mod tests {
        }
    }

+    #[test]
+    fn paste_artifact_segment_roundtrips_without_body() {
+        let artifact = PasteArtifactRef {
+            artifact_id: "019ca7c8-57b6-7f05-8edf-524147aba7b2".to_string(),
+            created_at_ms: 1_700_000_000_000,
+            media_type: PasteArtifactMediaType::TextPlainUtf8,
+            availability: PasteArtifactAvailability::Available,
+            byte_len: 65_536,
+            char_count: 65_530,
+            line_count: 200,
+            sha256: "a".repeat(64),
+            source_entry_id: "entry-1".to_string(),
+        };
+        let segment = Segment::PasteArtifact {
+            artifact: artifact.clone(),
+        };
+        let json = serde_json::to_string(&segment).unwrap();
+        assert!(!json.contains("pasted body"));
+        assert_eq!(serde_json::from_str::<Segment>(&json).unwrap(), segment);
+        let projected = Segment::flatten_to_text(&[segment]);
+        assert!(projected.contains(&artifact.artifact_id));
+        assert!(projected.contains("SearchInputArtifact"));
+        assert!(projected.contains("ReadInputArtifact"));
+        assert!(!projected.contains("pasted body"));
+    }
+
+    #[test]
+    fn uploaded_file_segment_roundtrips_without_path_or_body() {
+        let file = UploadedFileRef {
+            artifact_id: "019ca7c8-57b6-7f05-8edf-524147aba7b3".to_string(),
+            file_name: "notes.md".to_string(),
+            media_type: "text/markdown".to_string(),
+            created_at_ms: 1_700_000_000_001,
+            availability: UploadedFileAvailability::Available,
+            byte_len: 128,
+            sha256: "b".repeat(64),
+            source_entry_id: Some("entry-2".to_string()),
+        };
+        let segment = Segment::UploadedFile { file: file.clone() };
+        let json = serde_json::to_string(&segment).unwrap();
+        assert!(!json.contains("/home/user/private"));
+        assert!(!json.contains("file body"));
+        assert_eq!(serde_json::from_str::<Segment>(&json).unwrap(), segment);
+        let projected = Segment::flatten_to_text(&[segment]);
+        assert!(projected.contains("notes.md"));
+        assert!(projected.contains(&file.artifact_id));
+        assert!(projected.contains("ReadInputArtifact"));
+    }
+
    #[test]
    fn method_run_flow_segment_roundtrip() {
        let method = Method::Run {
@@ -1377,7 +1704,7 @@ mod tests {
        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed["event"], "completions");
        assert_eq!(parsed["data"]["kind"], "file");
-        assert_eq!(parsed["data"]["entries"][0]["value"], "clear");
+        assert_eq!(parsed["data"]["entries"][0]["value"], "src/main.rs");

        // is_dir defaults to false on inbound payloads that omit it.
        let inbound =
@@ -1397,7 +1724,17 @@ mod tests {
    #[test]
    fn event_snapshot_format() {
        let event = Event::Snapshot {
-            entries: vec![serde_json::json!({"kind": "user_input", "ts": 1, "segments": []})],
+            session: SessionSnapshot {
+                entries: vec![SessionSnapshotEntry {
+                    entry_id: "entry-1".into(),
+                    timestamp: 1,
+                    provenance: SessionEntryProvenance::HumanInput,
+                    derived_from: Vec::new(),
+                    data: SessionSnapshotEntryData::UserInput {
+                        segments: Vec::new(),
+                    },
+                }],
+            },
            greeting: Greeting {
                worker_name: "test".into(),
                cwd: "/tmp".into(),
@@ -1415,8 +1752,12 @@ mod tests {
        let json = serde_json::to_string(&event).unwrap();
        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed["event"], "snapshot");
-        assert!(parsed["data"]["entries"].is_array());
-        assert_eq!(parsed["data"]["entries"][0]["kind"], "user_input");
+        assert!(parsed["data"]["session"]["entries"].is_array());
+        assert_eq!(
+            parsed["data"]["session"]["entries"][0]["kind"],
+            "user_input"
+        );
+        assert_eq!(parsed["data"]["session"]["entries"][0]["timestamp"], 1);
        assert_eq!(parsed["data"]["greeting"]["worker_name"], "test");
        assert_eq!(parsed["data"]["greeting"]["tools"][0], "Read");
        assert_eq!(parsed["data"]["greeting"]["context_window"], 200_000);
@@ -1426,7 +1767,7 @@ mod tests {

    #[test]
    fn event_snapshot_in_flight_roundtrip_and_default() {
-        let inbound = r#"{"event":"snapshot","data":{"entries":[],"greeting":{"worker_name":"test","cwd":"/tmp","provider":"p","model":"m","scope_summary":"s","tools":[]},"status":"running"}}"#;
+        let inbound = r#"{"event":"snapshot","data":{"session":{"entries":[]},"greeting":{"worker_name":"test","cwd":"/tmp","provider":"p","model":"m","scope_summary":"s","tools":[]},"status":"running"}}"#;
        let decoded: Event = serde_json::from_str(inbound).unwrap();
        match decoded {
            Event::Snapshot { in_flight, .. } => assert!(in_flight.is_empty()),
@@ -1434,7 +1775,9 @@ mod tests {
        }

        let event = Event::Snapshot {
+            session: SessionSnapshot {
                entries: Vec::new(),
+            },
            greeting: Greeting {
                worker_name: "test".into(),
                cwd: "/tmp".into(),
@@ -1500,15 +1843,17 @@ mod tests {
    #[test]
    fn event_segment_rotated_roundtrip() {
        let event = Event::SegmentRotated {
-            entry: serde_json::json!({"kind": "segment_start", "ts": 1, "history": []}),
+            session: SessionSnapshot {
+                entries: Vec::new(),
+            },
        };
        let json = serde_json::to_string(&event).unwrap();
        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed["event"], "segment_rotated");
-        assert_eq!(parsed["data"]["entry"]["kind"], "segment_start");
+        assert!(parsed["data"]["session"]["entries"].is_array());
        let decoded: Event = serde_json::from_str(&json).unwrap();
        match decoded {
-            Event::SegmentRotated { entry } => assert_eq!(entry["kind"], "segment_start"),
+            Event::SegmentRotated { session } => assert!(session.entries.is_empty()),
            other => panic!("expected SegmentRotated, got {other:?}"),
        }
    }
@@ -1584,8 +1929,8 @@ mod tests {
    }

    #[test]
-    fn event_snapshot_legacy_without_status_defaults_to_idle() {
-        let json = r#"{"event":"snapshot","data":{"entries":[],"greeting":{"worker_name":"test","cwd":"/tmp","provider":"anthropic","model":"claude","scope_summary":"","tools":[]}}}"#;
+    fn event_snapshot_without_status_defaults_to_idle() {
+        let json = r#"{"event":"snapshot","data":{"session":{"entries":[]},"greeting":{"worker_name":"test","cwd":"/tmp","provider":"anthropic","model":"claude","scope_summary":"","tools":[]}}}"#;
        let decoded: Event = serde_json::from_str(json).unwrap();
        match decoded {
            Event::Snapshot {
@@ -1732,45 +2077,74 @@ mod tests {
        assert_eq!(parsed["data"]["timestamp_ms"], 1_700_000_000_000i64);
    }

+    fn test_compaction_lifecycle(state: CompactionLifecycleState) -> CompactionLifecycle {
+        CompactionLifecycle {
+            schema_version: 2,
+            compaction_id: "0192f0e8-4d84-7d6e-a000-000000000000".into(),
+            revision: 1,
+            internal_worker: None,
+            state,
+            started_at_ms: 1_700_000_000_000,
+            ended_at_ms: None,
+            summary: None,
+            error: None,
+            new_segment_id: None,
+        }
+    }
+
    #[test]
    fn event_compact_start_roundtrip() {
-        let event = Event::CompactStart;
+        let event = Event::CompactStart {
+            lifecycle: test_compaction_lifecycle(CompactionLifecycleState::Running),
+        };
        let json = serde_json::to_string(&event).unwrap();
-        assert_eq!(json, r#"{"event":"compact_start"}"#);
+        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
+        assert_eq!(parsed["event"], "compact_start");
+        assert_eq!(parsed["data"]["lifecycle"]["state"], "running");
        let decoded: Event = serde_json::from_str(&json).unwrap();
-        assert!(matches!(decoded, Event::CompactStart));
+        assert!(matches!(decoded, Event::CompactStart { lifecycle } if lifecycle.revision == 1));
    }

    #[test]
    fn event_compact_done_roundtrip() {
        let id = uuid::Uuid::parse_str("0192f0e8-4d84-7d6e-a000-000000000001").unwrap();
-        let event = Event::CompactDone { new_segment_id: id };
+        let mut lifecycle = test_compaction_lifecycle(CompactionLifecycleState::Done);
+        lifecycle.new_segment_id = Some(id.to_string());
+        lifecycle.summary = Some("accepted summary".into());
+        let event = Event::CompactDone { lifecycle };
        let json = serde_json::to_string(&event).unwrap();
        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed["event"], "compact_done");
        assert_eq!(
-            parsed["data"]["new_segment_id"],
+            parsed["data"]["lifecycle"]["new_segment_id"],
            "0192f0e8-4d84-7d6e-a000-000000000001"
        );
        let decoded: Event = serde_json::from_str(&json).unwrap();
        match decoded {
-            Event::CompactDone { new_segment_id } => assert_eq!(new_segment_id, id),
+            Event::CompactDone { lifecycle } => {
+                assert_eq!(
+                    lifecycle.new_segment_id.as_deref(),
+                    Some(id.to_string().as_str())
+                )
+            }
            other => panic!("expected CompactDone, got {other:?}"),
        }
    }

    #[test]
    fn event_compact_failed_roundtrip() {
-        let event = Event::CompactFailed {
-            error: "provider 429".into(),
-        };
+        let mut lifecycle = test_compaction_lifecycle(CompactionLifecycleState::Failed);
+        lifecycle.error = Some("provider 429".into());
+        let event = Event::CompactFailed { lifecycle };
        let json = serde_json::to_string(&event).unwrap();
        let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed["event"], "compact_failed");
-        assert_eq!(parsed["data"]["error"], "provider 429");
+        assert_eq!(parsed["data"]["lifecycle"]["error"], "provider 429");
        let decoded: Event = serde_json::from_str(&json).unwrap();
        match decoded {
-            Event::CompactFailed { error } => assert_eq!(error, "provider 429"),
+            Event::CompactFailed { lifecycle } => {
+                assert_eq!(lifecycle.error.as_deref(), Some("provider 429"))
+            }
            other => panic!("expected CompactFailed, got {other:?}"),
        }
    }
@@ -1781,6 +2155,7 @@ mod tests {
            id: "call_1".into(),
            summary: "Read 128 bytes".into(),
            output: Some("hello world".into()),
+            disposition: Some(ToolResultDisposition::Success),
            is_error: false,
        };
        let json = serde_json::to_string(&event).unwrap();
@@ -1797,11 +2172,13 @@ mod tests {
                id,
                summary,
                output,
+                disposition,
                is_error,
            } => {
                assert_eq!(id, "call_1");
                assert_eq!(summary, "Read 128 bytes");
                assert_eq!(output.as_deref(), Some("hello world"));
+                assert_eq!(disposition, Some(ToolResultDisposition::Success));
                assert!(!is_error);
            }
            other => panic!("expected ToolResult, got {other:?}"),
@@ -1814,6 +2191,7 @@ mod tests {
            id: "call_2".into(),
            summary: "ok".into(),
            output: None,
+            disposition: Some(ToolResultDisposition::Success),
            is_error: false,
        };
        let json = serde_json::to_string(&event).unwrap();
@@ -1829,6 +2207,7 @@ mod tests {
            id: "call_3".into(),
            summary: "invalid argument".into(),
            output: None,
+            disposition: Some(ToolResultDisposition::Error),
            is_error: true,
        };
        let json = serde_json::to_string(&event).unwrap();
@@ -1962,11 +2341,11 @@ mod tests {
    }

    #[test]
-    fn legacy_snapshot_defaults_internal_workers_to_empty() {
+    fn snapshot_defaults_internal_workers_to_empty() {
        let snapshot: Event = serde_json::from_value(serde_json::json!({
            "event": "snapshot",
            "data": {
-                "entries": [],
+                "session": { "entries": [] },
                "greeting": {
                    "worker_name": "parent",
                    "cwd": ".",
@@ -170,6 +170,23 @@ fn validate_identifier(
    Ok(())
 }

+fn validate_repository_key(value: &str) -> Result<(), SubscriptionValidationError> {
+    let bytes = value.as_bytes();
+    if bytes.is_empty()
+        || bytes.len() > 64
+        || bytes.first() == Some(&b'-')
+        || bytes.last() == Some(&b'-')
+        || !bytes
+            .iter()
+            .all(|byte| byte.is_ascii_lowercase() || byte.is_ascii_digit() || *byte == b'-')
+    {
+        return Err(SubscriptionValidationError::InvalidIdentifier {
+            field: "repository_key",
+        });
+    }
+    Ok(())
+}
+
 fn validate_rejection_message(message: &str) -> Result<(), SubscriptionValidationError> {
    if message.is_empty() {
        return Err(SubscriptionValidationError::EmptyRejectionMessage);
@@ -567,7 +584,12 @@ pub struct SubscriptionWorker {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub profile: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "typescript", ts(skip))]
    pub repository_id: Option<String>,
+    /// Workspace-facing Repository key. Runtime producers leave this unset and
+    /// Workspace Server projections replace `repository_id` with this field.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub repository_key: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub working_directory_id: Option<SubscriptionWorkdirId>,
 }
@@ -584,6 +606,14 @@ impl SubscriptionWorker {
        if let Some(repository_id) = &self.repository_id {
            validate_identifier("repository_id", repository_id, MAX_RESOURCE_ID_BYTES)?;
        }
+        if let Some(repository_key) = &self.repository_key {
+            validate_repository_key(repository_key)?;
+        }
+        if self.repository_id.is_some() && self.repository_key.is_some() {
+            return Err(SubscriptionValidationError::InvalidIdentifier {
+                field: "repository_authority",
+            });
+        }
        if let Some(working_directory_id) = &self.working_directory_id {
            working_directory_id.validate()?;
        }
@@ -595,7 +625,13 @@ impl SubscriptionWorker {
 #[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
 pub struct SubscriptionWorkdir {
    pub working_directory_id: SubscriptionWorkdirId,
-    pub repository_id: String,
+    /// Runtime-internal Repository id. Workspace-facing TypeScript contracts
+    /// omit this field and require `repository_key` from the Server projection.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[cfg_attr(feature = "typescript", ts(skip))]
+    pub repository_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub repository_key: Option<String>,
    pub state: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub primary_worker_id: Option<SubscriptionWorkerId>,
@@ -604,7 +640,41 @@ pub struct SubscriptionWorkdir {
 impl SubscriptionWorkdir {
    pub fn validate(&self) -> Result<(), SubscriptionValidationError> {
        self.working_directory_id.validate()?;
-        validate_identifier("repository_id", &self.repository_id, MAX_RESOURCE_ID_BYTES)?;
+        match (&self.repository_id, &self.repository_key) {
+            (Some(repository_id), None) => {
+                validate_identifier("repository_id", repository_id, MAX_RESOURCE_ID_BYTES)?;
+            }
+            (None, Some(repository_key)) => validate_repository_key(repository_key)?,
+            _ => {
+                return Err(SubscriptionValidationError::InvalidIdentifier {
+                    field: "repository_authority",
+                });
+            }
+        }
+        validate_identifier("workdir_state", &self.state, MAX_RESOURCE_ID_BYTES)?;
+        if let Some(worker_id) = &self.primary_worker_id {
+            worker_id.validate()?;
+        }
+        Ok(())
+    }
+}
+
+/// Workspace-facing Workdir summary. Backend-generated Repository UUIDs never
+/// enter this DTO; Workspace Server must resolve the required Repository key.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+pub struct WorkspaceSubscriptionWorkdir {
+    pub working_directory_id: SubscriptionWorkdirId,
+    pub repository_key: String,
+    pub state: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub primary_worker_id: Option<SubscriptionWorkerId>,
+}
+
+impl WorkspaceSubscriptionWorkdir {
+    pub fn validate(&self) -> Result<(), SubscriptionValidationError> {
+        self.working_directory_id.validate()?;
+        validate_repository_key(&self.repository_key)?;
        validate_identifier("workdir_state", &self.state, MAX_RESOURCE_ID_BYTES)?;
        if let Some(worker_id) = &self.primary_worker_id {
            worker_id.validate()?;
@@ -625,7 +695,7 @@ pub enum SubscriptionSnapshot {
        events: Vec<WorkerProtocolEvent>,
    },
    WorkspaceWorkdirs {
-        workdirs: Vec<SubscriptionWorkdir>,
+        workdirs: Vec<WorkspaceSubscriptionWorkdir>,
    },
 }

@@ -693,7 +763,7 @@ pub enum SubscriptionEventPayload {
        event: WorkerProtocolEvent,
    },
    WorkdirUpserted {
-        workdir: SubscriptionWorkdir,
+        workdir: WorkspaceSubscriptionWorkdir,
    },
    WorkdirRemoved {
        working_directory_id: SubscriptionWorkdirId,
@@ -811,10 +881,42 @@ mod tests {
            display_name: Some(format!("Worker {value}")),
            profile: Some("builtin:coder".to_string()),
            repository_id: None,
+            repository_key: None,
            working_directory_id: None,
        }
    }

+    #[test]
+    fn runtime_and_workspace_repository_identity_projections_do_not_alias() {
+        let mut runtime_worker = worker("worker-1");
+        runtime_worker.repository_id = Some("01890f47-3c22-7cc0-98c4-dc0c0c07398f".to_string());
+        runtime_worker.validate().unwrap();
+        let runtime_json = serde_json::to_value(&runtime_worker).unwrap();
+        assert_eq!(
+            runtime_json["repository_id"],
+            "01890f47-3c22-7cc0-98c4-dc0c0c07398f"
+        );
+        assert!(runtime_json.get("repository_key").is_none());
+
+        let mut workspace_worker = worker("worker-1");
+        workspace_worker.repository_key = Some("main".to_string());
+        workspace_worker.validate().unwrap();
+        let workspace_json = serde_json::to_value(&workspace_worker).unwrap();
+        assert_eq!(workspace_json["repository_key"], "main");
+        assert!(workspace_json.get("repository_id").is_none());
+
+        let workspace_workdir = WorkspaceSubscriptionWorkdir {
+            working_directory_id: SubscriptionWorkdirId::new("workdir-1").unwrap(),
+            repository_key: "main".to_string(),
+            state: "active".to_string(),
+            primary_worker_id: Some(worker_id("worker-1")),
+        };
+        workspace_workdir.validate().unwrap();
+        let workdir_json = serde_json::to_value(&workspace_workdir).unwrap();
+        assert_eq!(workdir_json["repository_key"], "main");
+        assert!(workdir_json.get("repository_id").is_none());
+    }
+
    #[test]
    fn subscribe_frame_has_stable_versioned_json_shape() {
        let frame = SubscriptionFrame::new(SubscriptionFramePayload::Request(
@@ -4,18 +4,22 @@ use ts_rs::{Config, TS};

 use crate::{
    Alert, AlertLevel, AlertSource, CommandEvent, CommandSnapshot, CommandStatus, CommandStream,
-    CommandStreamSlice, CompletionEntry, CompletionKind, ErrorCode, Event, Greeting, InFlightBlock,
-    InFlightSnapshot, InFlightToolCallState, InternalWorkerKind, InternalWorkerRef,
-    InternalWorkerSnapshot, InvokeKind, MemoryWorkerEvent, Method, Permission, RewindSummary,
-    RewindTarget, RewindTargetId, RunResult, ScopeRule, Segment, TurnResult, WorkerEvent,
+    CommandStreamSlice, CompactionLifecycle, CompactionLifecycleState, CompletionEntry,
+    CompletionKind, ErrorCode, Event, Greeting, InFlightBlock, InFlightSnapshot,
+    InFlightToolCallState, InternalWorkerKind, InternalWorkerRef, InternalWorkerSnapshot,
+    InvokeKind, MemoryWorkerEvent, Method, PasteArtifactAvailability, PasteArtifactMediaType,
+    PasteArtifactRef, Permission, RewindSummary, RewindTarget, RewindTargetId, RunResult,
+    ScopeRule, Segment, SessionContentPart, SessionEntryProvenance, SessionMessageRole,
+    SessionSnapshot, SessionSnapshotEntry, SessionSnapshotEntryData, SessionToolAttachment,
+    ToolResultDisposition, TurnResult, UploadedFileAvailability, UploadedFileRef, WorkerEvent,
    WorkerStatus,
    subscription::{
        EventSubscriptionSelector, SubscriptionEvent, SubscriptionEventPayload, SubscriptionFrame,
        SubscriptionFramePayload, SubscriptionId, SubscriptionRejectionCode, SubscriptionRequest,
        SubscriptionRequestId, SubscriptionResponse, SubscriptionSnapshot,
-        SubscriptionTerminationCode, SubscriptionWorkdir, SubscriptionWorkdirId,
-        SubscriptionWorker, SubscriptionWorkerId, SubscriptionWorkerIds,
-        SubscriptionWorkerProtocolMethod, SubscriptionWorkerState,
+        SubscriptionTerminationCode, SubscriptionWorkdirId, SubscriptionWorker,
+        SubscriptionWorkerId, SubscriptionWorkerIds, SubscriptionWorkerProtocolMethod,
+        SubscriptionWorkerState, WorkspaceSubscriptionWorkdir,
    },
 };

@@ -45,6 +49,7 @@ pub fn generated_protocol_types() -> String {
    push_decl::<TurnResult>(&cfg, &mut output);
    push_decl::<InvokeKind>(&cfg, &mut output);
    push_decl::<RunResult>(&cfg, &mut output);
+    push_decl::<ToolResultDisposition>(&cfg, &mut output);
    push_decl::<ErrorCode>(&cfg, &mut output);
    push_decl::<Permission>(&cfg, &mut output);
    push_decl::<InFlightToolCallState>(&cfg, &mut output);
@@ -53,6 +58,10 @@ pub fn generated_protocol_types() -> String {
    push_decl::<CommandStreamSlice>(&cfg, &mut output);
    push_decl::<CommandSnapshot>(&cfg, &mut output);
    push_decl::<CommandEvent>(&cfg, &mut output);
+    push_decl::<CompactionLifecycleState>(&cfg, &mut output);
+    push_decl::<CompactionLifecycle>(&cfg, &mut output);
+    push_decl::<UploadedFileAvailability>(&cfg, &mut output);
+    push_decl::<UploadedFileRef>(&cfg, &mut output);
    push_decl::<ScopeRule>(&cfg, &mut output);
    push_decl::<CompletionEntry>(&cfg, &mut output);
    push_decl::<RewindTargetId>(&cfg, &mut output);
@@ -60,12 +69,22 @@ pub fn generated_protocol_types() -> String {
    push_decl::<RewindSummary>(&cfg, &mut output);
    push_decl::<InFlightBlock>(&cfg, &mut output);
    push_decl::<InFlightSnapshot>(&cfg, &mut output);
+    push_decl::<SessionEntryProvenance>(&cfg, &mut output);
+    push_decl::<SessionMessageRole>(&cfg, &mut output);
+    push_decl::<SessionContentPart>(&cfg, &mut output);
+    push_decl::<SessionToolAttachment>(&cfg, &mut output);
+    push_decl::<SessionSnapshotEntryData>(&cfg, &mut output);
+    push_decl::<SessionSnapshotEntry>(&cfg, &mut output);
+    push_decl::<SessionSnapshot>(&cfg, &mut output);
    push_decl::<InternalWorkerKind>(&cfg, &mut output);
    push_decl::<InternalWorkerRef>(&cfg, &mut output);
    push_decl::<InternalWorkerSnapshot>(&cfg, &mut output);
    push_decl::<Greeting>(&cfg, &mut output);
    push_decl::<Alert>(&cfg, &mut output);
    push_decl::<MemoryWorkerEvent>(&cfg, &mut output);
+    push_decl::<PasteArtifactMediaType>(&cfg, &mut output);
+    push_decl::<PasteArtifactAvailability>(&cfg, &mut output);
+    push_decl::<PasteArtifactRef>(&cfg, &mut output);
    push_decl::<Segment>(&cfg, &mut output);
    push_decl::<WorkerEvent>(&cfg, &mut output);
    push_decl::<SubscriptionRequestId>(&cfg, &mut output);
@@ -76,7 +95,7 @@ pub fn generated_protocol_types() -> String {
    push_decl::<SubscriptionWorkerState>(&cfg, &mut output);
    push_decl::<EventSubscriptionSelector>(&cfg, &mut output);
    push_decl::<SubscriptionWorker>(&cfg, &mut output);
-    push_decl::<SubscriptionWorkdir>(&cfg, &mut output);
+    push_decl::<WorkspaceSubscriptionWorkdir>(&cfg, &mut output);
    push_decl::<SubscriptionSnapshot>(&cfg, &mut output);
    push_decl::<SubscriptionEventPayload>(&cfg, &mut output);
    push_decl::<SubscriptionRejectionCode>(&cfg, &mut output);
@@ -120,6 +139,14 @@ fn export_decl(decl: &str) -> String {
 mod tests {
    use super::*;

+    #[test]
+    fn workspace_typescript_omits_runtime_repository_ids() {
+        let generated = generated_protocol_types();
+        assert!(!generated.contains("repository_id?:"), "{generated}");
+        assert!(!generated.contains("repository_id:"), "{generated}");
+        assert!(generated.contains("repository_key"), "{generated}");
+    }
+
    #[test]
    fn generated_protocol_types_are_current() {
        let expected = generated_protocol_types();
@@ -8,12 +8,17 @@ license.workspace = true
 [dependencies]
 base64.workspace = true
 agen = { workspace = true }
+fs4.workspace = true
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+sha2.workspace = true
 uuid = { workspace = true, features = ["v7", "serde"] }
 thiserror = { workspace = true }
 protocol = { workspace = true }
 tracing.workspace = true
+unicode-normalization = "0.1.25"
+unicode-properties = { version = "0.1.4", features = ["general-category"] }
+unicode-security = "0.1.2"

 [dev-dependencies]
 async-trait = { workspace = true }
@@ -16,9 +16,18 @@
 //! enumerable by the picker.

 use crate::event_trace::TraceEntry;
+use crate::paste_artifact::{read_from_dir, write_to_dir};
 use crate::segment_log::LogEntry;
 use crate::store::{Store, StoreError};
-use crate::{SegmentId, SessionId};
+use crate::uploaded_file::{
+    bind_uploaded_file, clear_uploaded_file_binding, copy_committed_uploaded_files,
+    delete_uncommitted_uploaded_files, delete_uploaded_file, list_uploaded_file_refs,
+    read_uploaded_file, read_uploaded_file_by_id, write_uploaded_file,
+};
+use crate::{
+    PasteArtifactLimits, SegmentId, SessionId, UploadedFileLimits, UploadedFileUploadContext,
+};
+use protocol::{PasteArtifactRef, UploadedFileRef};
 use std::fs;
 use std::io::{Read, Seek, SeekFrom, Write};
 use std::path::{Path, PathBuf};
@@ -109,6 +118,50 @@ impl FsStore {
            .join(format!("{segment_id}.trace.jsonl"))
    }

+    fn paste_artifact_dir(&self, session_id: SessionId) -> PathBuf {
+        self.session_dir(session_id).join("artifacts").join("paste")
+    }
+
+    fn uploaded_file_is_referenced(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<bool, StoreError> {
+        fn segments_contain(segments: &[protocol::Segment], artifact_id: &str) -> bool {
+            segments.iter().any(|segment| {
+                matches!(
+                    segment,
+                    protocol::Segment::UploadedFile { file }
+                        if file.artifact_id == artifact_id
+                )
+            })
+        }
+
+        for segment_id in self.list_segments(session_id)? {
+            for entry in self.read_all(session_id, segment_id)? {
+                let referenced = match entry {
+                    LogEntry::AnnotatedUserInput { segments, .. } => {
+                        segments_contain(&segments, artifact_id)
+                    }
+                    LogEntry::InputSegmentsCheckpoint { user_segments, .. } => user_segments
+                        .iter()
+                        .any(|segments| segments_contain(segments, artifact_id)),
+                    _ => false,
+                };
+                if referenced {
+                    return Ok(true);
+                }
+            }
+        }
+        Ok(false)
+    }
+
+    #[cfg(test)]
+    fn paste_artifact_path(&self, session_id: SessionId, artifact_id: &str) -> PathBuf {
+        self.paste_artifact_dir(session_id)
+            .join(format!("{artifact_id}.json"))
+    }
+
    fn append_line(&self, path: &Path, line: &str) -> Result<(), StoreError> {
        let _guard = self
            .append_lock
@@ -350,6 +403,171 @@ impl Store for FsStore {
        Ok(complete.lines().filter(|l| !l.trim().is_empty()).count())
    }

+    fn write_paste_artifact(
+        &self,
+        session_id: SessionId,
+        source_entry_id: &str,
+        content: &str,
+        limits: PasteArtifactLimits,
+    ) -> Result<PasteArtifactRef, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        write_to_dir(
+            &self.paste_artifact_dir(session_id),
+            source_entry_id,
+            content,
+            limits,
+        )
+    }
+
+    fn read_paste_artifact(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<(PasteArtifactRef, String), StoreError> {
+        read_from_dir(&self.paste_artifact_dir(session_id), artifact_id)
+    }
+
+    fn write_uploaded_file(
+        &self,
+        session_id: SessionId,
+        file_name: &str,
+        media_type: &str,
+        content: &[u8],
+        limits: UploadedFileLimits,
+    ) -> Result<UploadedFileRef, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        write_uploaded_file(
+            &self.paste_artifact_dir(session_id),
+            file_name,
+            media_type,
+            content,
+            None,
+            limits,
+        )
+    }
+
+    fn write_uploaded_file_with_context(
+        &self,
+        session_id: SessionId,
+        file_name: &str,
+        media_type: &str,
+        content: &[u8],
+        context: &UploadedFileUploadContext,
+        limits: UploadedFileLimits,
+    ) -> Result<UploadedFileRef, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        write_uploaded_file(
+            &self.paste_artifact_dir(session_id),
+            file_name,
+            media_type,
+            content,
+            Some(context),
+            limits,
+        )
+    }
+
+    fn read_uploaded_file(
+        &self,
+        session_id: SessionId,
+        reference: &UploadedFileRef,
+    ) -> Result<Vec<u8>, StoreError> {
+        read_uploaded_file(&self.paste_artifact_dir(session_id), reference)
+    }
+
+    fn read_uploaded_file_by_id(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<(UploadedFileRef, Vec<u8>), StoreError> {
+        read_uploaded_file_by_id(&self.paste_artifact_dir(session_id), artifact_id)
+    }
+
+    fn bind_uploaded_file(
+        &self,
+        session_id: SessionId,
+        reference: &UploadedFileRef,
+        source_entry_id: &str,
+    ) -> Result<UploadedFileRef, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        let dir = self.paste_artifact_dir(session_id);
+        match bind_uploaded_file(&dir, reference, source_entry_id) {
+            Err(StoreError::ArtifactAlreadyCommitted) => {
+                let (stored, _) = read_uploaded_file_by_id(&dir, &reference.artifact_id)?;
+                let previous_source = stored
+                    .source_entry_id
+                    .ok_or(StoreError::ArtifactIntegrityMismatch)?;
+                if self.uploaded_file_is_referenced(session_id, &reference.artifact_id)? {
+                    return Err(StoreError::ArtifactAlreadyCommitted);
+                }
+                clear_uploaded_file_binding(&dir, &reference.artifact_id, &previous_source)?;
+                bind_uploaded_file(&dir, reference, source_entry_id)
+            }
+            result => result,
+        }
+    }
+
+    fn delete_uploaded_file(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<bool, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        delete_uploaded_file(&self.paste_artifact_dir(session_id), artifact_id)
+    }
+
+    fn delete_uncommitted_uploaded_files(&self, session_id: SessionId) -> Result<u64, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        let dir = self.paste_artifact_dir(session_id);
+        let mut removed = delete_uncommitted_uploaded_files(&dir)?;
+        for reference in list_uploaded_file_refs(&dir)? {
+            let Some(source_entry_id) = reference.source_entry_id.as_deref() else {
+                continue;
+            };
+            if !self.uploaded_file_is_referenced(session_id, &reference.artifact_id)? {
+                clear_uploaded_file_binding(&dir, &reference.artifact_id, source_entry_id)?;
+                if delete_uploaded_file(&dir, &reference.artifact_id)? {
+                    removed = removed
+                        .checked_add(1)
+                        .ok_or(StoreError::ArtifactQuotaExceeded)?;
+                }
+            }
+        }
+        Ok(removed)
+    }
+
+    fn copy_committed_uploaded_files(
+        &self,
+        source_session_id: SessionId,
+        target_session_id: SessionId,
+    ) -> Result<u64, StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("session store append lock was poisoned"))?;
+        copy_committed_uploaded_files(
+            &self.paste_artifact_dir(source_session_id),
+            &self.paste_artifact_dir(target_session_id),
+        )
+    }
+
    fn append_trace(
        &self,
        session_id: SessionId,
@@ -398,4 +616,424 @@ mod tests {
        store.create_segment(session_id, segment_id, &[]).unwrap();
        assert!(store.session_modified_at(session_id).unwrap().is_some());
    }
+
+    #[test]
+    fn paste_artifacts_are_atomic_integrity_checked_and_session_scoped() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let owner = new_session_id();
+        let other = new_session_id();
+        let content = "αβγ\nsecond line\n";
+        let reference = store
+            .write_paste_artifact(owner, "entry-1", content, PasteArtifactLimits::default())
+            .unwrap();
+
+        assert_eq!(reference.byte_len, content.len() as u64);
+        assert!(reference.created_at_ms > 0);
+        assert_eq!(
+            reference.media_type,
+            protocol::PasteArtifactMediaType::TextPlainUtf8
+        );
+        assert_eq!(
+            reference.availability,
+            protocol::PasteArtifactAvailability::Available
+        );
+        assert_eq!(reference.char_count, content.chars().count() as u64);
+        assert_eq!(reference.source_entry_id, "entry-1");
+        assert_eq!(
+            store
+                .read_paste_artifact(owner, &reference.artifact_id)
+                .unwrap()
+                .1,
+            content
+        );
+        assert!(matches!(
+            store.read_paste_artifact(other, &reference.artifact_id),
+            Err(StoreError::PasteArtifactNotFound(_))
+        ));
+        assert!(
+            self::fs::read_dir(store.paste_artifact_dir(owner))
+                .unwrap()
+                .all(|entry| !entry
+                    .unwrap()
+                    .file_name()
+                    .to_string_lossy()
+                    .ends_with(".tmp"))
+        );
+        let very_large = "z".repeat(1024 * 1024);
+        let very_large_ref = store
+            .write_paste_artifact(
+                owner,
+                "entry-2",
+                &very_large,
+                PasteArtifactLimits::default(),
+            )
+            .unwrap();
+        assert_eq!(
+            store
+                .read_paste_artifact(owner, &very_large_ref.artifact_id)
+                .unwrap()
+                .1,
+            very_large
+        );
+    }
+
+    #[test]
+    fn concurrent_paste_writes_atomically_enforce_aggregate_caps() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let session_id = new_session_id();
+        let barrier = std::sync::Arc::new(std::sync::Barrier::new(3));
+        let limits = PasteArtifactLimits {
+            max_artifact_bytes: 4,
+            max_session_bytes: 8,
+            max_session_artifacts: 1,
+        };
+        let mut handles = Vec::new();
+        for entry_id in ["entry-1", "entry-2"] {
+            let root = tmp.path().to_path_buf();
+            let barrier = barrier.clone();
+            handles.push(std::thread::spawn(move || {
+                let store = FsStore::new(root).unwrap();
+                barrier.wait();
+                store.write_paste_artifact(session_id, entry_id, "1234", limits)
+            }));
+        }
+        barrier.wait();
+        let results = handles
+            .into_iter()
+            .map(|handle| handle.join().unwrap())
+            .collect::<Vec<_>>();
+        assert_eq!(results.iter().filter(|result| result.is_ok()).count(), 1);
+        assert_eq!(
+            results
+                .iter()
+                .filter(|result| matches!(result, Err(StoreError::PasteArtifactLimit(_))))
+                .count(),
+            1
+        );
+        assert_eq!(
+            std::fs::read_dir(
+                FsStore::new(tmp.path())
+                    .unwrap()
+                    .paste_artifact_dir(session_id)
+            )
+            .unwrap()
+            .filter_map(Result::ok)
+            .filter(
+                |entry| entry.path().extension().and_then(|value| value.to_str()) == Some("json")
+            )
+            .count(),
+            1
+        );
+    }
+
+    #[test]
+    fn uploaded_file_persists_trusted_upload_context_without_projecting_it() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let session_id = new_session_id();
+        let context = UploadedFileUploadContext {
+            upload_id: "upload-1".into(),
+            principal_id: "account-1".into(),
+            workspace_id: "workspace-1".into(),
+            runtime_id: "runtime-1".into(),
+            worker_id: "worker-1".into(),
+        };
+        let reference = store
+            .write_uploaded_file_with_context(
+                session_id,
+                "notes.txt",
+                "text/plain",
+                b"hello",
+                &context,
+                UploadedFileLimits::default(),
+            )
+            .unwrap();
+        let raw = fs::read_to_string(
+            store
+                .paste_artifact_dir(session_id)
+                .join(format!("{}.file.json", reference.artifact_id)),
+        )
+        .unwrap();
+        assert!(raw.contains("account-1"));
+        assert!(raw.contains("workspace-1"));
+        assert!(raw.contains("runtime-1"));
+        assert!(raw.contains("worker-1"));
+        assert!(
+            !serde_json::to_string(&reference)
+                .unwrap()
+                .contains("account-1")
+        );
+
+        let replay = store
+            .write_uploaded_file_with_context(
+                session_id,
+                "notes.txt",
+                "text/plain",
+                b"hello",
+                &context,
+                UploadedFileLimits::default(),
+            )
+            .unwrap();
+        assert_eq!(replay.artifact_id, reference.artifact_id);
+        assert!(matches!(
+            store.write_uploaded_file_with_context(
+                session_id,
+                "renamed.txt",
+                "text/plain",
+                b"hello",
+                &context,
+                UploadedFileLimits::default(),
+            ),
+            Err(StoreError::InvalidUploadedFileName)
+        ));
+    }
+
+    #[test]
+    fn uploaded_file_exact_replay_succeeds_at_session_count_limit() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let session_id = new_session_id();
+        let limits = UploadedFileLimits {
+            max_file_bytes: 1,
+            max_session_bytes: crate::DEFAULT_MAX_SESSION_UPLOADED_FILES,
+        };
+        let mut first = None;
+        for index in 0..crate::DEFAULT_MAX_SESSION_UPLOADED_FILES {
+            let reference = store
+                .write_uploaded_file(
+                    session_id,
+                    &format!("file-{index}.txt"),
+                    "text/plain",
+                    b"x",
+                    limits,
+                )
+                .unwrap();
+            first.get_or_insert(reference);
+        }
+
+        let replay = store
+            .write_uploaded_file(session_id, "file-0.txt", "text/plain", b"x", limits)
+            .unwrap();
+        assert_eq!(replay.artifact_id, first.unwrap().artifact_id);
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "overflow.txt", "text/plain", b"x", limits),
+            Err(StoreError::ArtifactQuotaExceeded)
+        ));
+    }
+
+    #[test]
+    fn uploaded_files_are_session_scoped_integrity_checked_and_removable() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let owner = new_session_id();
+        let other = new_session_id();
+        let limits = UploadedFileLimits {
+            max_file_bytes: 16,
+            max_session_bytes: 16,
+        };
+        let reference = store
+            .write_uploaded_file(owner, "notes.txt", "text/plain", b"hello", limits)
+            .unwrap();
+
+        assert_eq!(reference.file_name, "notes.txt");
+        assert_eq!(reference.media_type, "text/plain");
+        assert_eq!(reference.byte_len, 5);
+        assert_eq!(reference.source_entry_id, None);
+        assert_eq!(
+            store.read_uploaded_file(owner, &reference).unwrap(),
+            b"hello"
+        );
+        assert!(store.read_uploaded_file(other, &reference).is_err());
+
+        let mut forged = reference.clone();
+        forged.file_name = "other.txt".to_string();
+        assert!(matches!(
+            store.read_uploaded_file(owner, &forged),
+            Err(StoreError::ArtifactIntegrityMismatch)
+        ));
+        assert!(
+            store
+                .delete_uploaded_file(owner, &reference.artifact_id)
+                .unwrap()
+        );
+        assert!(
+            !store
+                .delete_uploaded_file(owner, &reference.artifact_id)
+                .unwrap()
+        );
+        assert!(store.read_uploaded_file(owner, &reference).is_err());
+    }
+
+    #[test]
+    fn uploaded_file_validation_and_shared_quota_fail_closed() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let session_id = new_session_id();
+        let limits = UploadedFileLimits {
+            max_file_bytes: 8,
+            max_session_bytes: 8,
+        };
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "../secret", "text/plain", b"x", limits),
+            Err(StoreError::InvalidUploadedFileName)
+        ));
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "notes.txt", "not a type", b"x", limits),
+            Err(StoreError::InvalidUploadedFileMediaType)
+        ));
+        assert!(matches!(
+            store.write_uploaded_file(
+                session_id,
+                "safe\u{202e}txt.exe",
+                "text/plain",
+                b"x",
+                limits
+            ),
+            Err(StoreError::InvalidUploadedFileName)
+        ));
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "image.png", "image/png", b"not a png", limits),
+            Err(StoreError::ArtifactIntegrityMismatch)
+        ));
+        let pending = store
+            .write_uploaded_file(session_id, "Readme.txt", "text/plain", b"x", limits)
+            .unwrap();
+        let replay = store
+            .write_uploaded_file(session_id, "Readme.txt", "text/plain", b"x", limits)
+            .unwrap();
+        assert_eq!(replay.artifact_id, pending.artifact_id);
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "README.txt", "text/plain", b"changed", limits),
+            Err(StoreError::InvalidUploadedFileName)
+        ));
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "ＲＥＡＤＭＥ.txt", "text/plain", b"y", limits),
+            Err(StoreError::InvalidUploadedFileName)
+        ));
+        store
+            .bind_uploaded_file(session_id, &pending, "entry-from-failed-submit")
+            .unwrap();
+        let bound = store
+            .bind_uploaded_file(session_id, &pending, "entry-upload")
+            .unwrap();
+        store
+            .create_segment(
+                session_id,
+                new_segment_id(),
+                &[LogEntry::InputSegmentsCheckpoint {
+                    ts: 1,
+                    user_segments: vec![vec![protocol::Segment::UploadedFile {
+                        file: bound.clone(),
+                    }]],
+                }],
+            )
+            .unwrap();
+        let other = store
+            .write_uploaded_file(session_id, "other.txt", "text/plain", b"z", limits)
+            .unwrap();
+        let stale = store
+            .write_uploaded_file(session_id, "stale.txt", "text/plain", b"s", limits)
+            .unwrap();
+        store
+            .bind_uploaded_file(session_id, &stale, "entry-never-committed")
+            .unwrap();
+        assert_eq!(
+            store.delete_uncommitted_uploaded_files(session_id).unwrap(),
+            2
+        );
+        assert!(store.read_uploaded_file(session_id, &other).is_err());
+        assert!(store.read_uploaded_file(session_id, &stale).is_err());
+        assert_eq!(store.read_uploaded_file(session_id, &bound).unwrap(), b"x");
+        let fork_session_id = new_session_id();
+        assert_eq!(
+            store
+                .copy_committed_uploaded_files(session_id, fork_session_id)
+                .unwrap(),
+            1
+        );
+        assert_eq!(
+            store.read_uploaded_file(fork_session_id, &bound).unwrap(),
+            b"x"
+        );
+        store
+            .write_paste_artifact(
+                session_id,
+                "entry-1",
+                "1234",
+                PasteArtifactLimits {
+                    max_artifact_bytes: 8,
+                    max_session_bytes: 8,
+                    max_session_artifacts: 4,
+                },
+            )
+            .unwrap();
+        assert!(matches!(
+            store.write_uploaded_file(session_id, "notes.txt", "text/plain", b"56789", limits),
+            Err(StoreError::ArtifactQuotaExceeded)
+        ));
+    }
+
+    #[test]
+    fn uploaded_file_names_reject_format_mixed_script_and_confusable_forms() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let session_id = new_session_id();
+        let limits = UploadedFileLimits::default();
+
+        for file_name in [
+            "safe\u{00ad}name.txt",
+            "safe\u{061c}name.txt",
+            "safe\u{180e}name.txt",
+            "safe\u{e0001}name.txt",
+            "p\u{0430}ypal.txt",
+            "report.\u{03c1}df",
+            "\u{0440}\u{0430}\u{0443}\u{0440}\u{0430}\u{04cf}.txt",
+            "\u{ff26}\u{ff49}\u{ff4c}\u{ff45}.txt",
+            "re\u{0301}sume\u{0301}.txt",
+        ] {
+            assert!(matches!(
+                store.write_uploaded_file(session_id, file_name, "text/plain", b"safe", limits),
+                Err(StoreError::InvalidUploadedFileName)
+            ));
+        }
+
+        for file_name in ["notes.txt", "résumé.txt", "日本語.txt", "📎.txt"] {
+            store
+                .write_uploaded_file(session_id, file_name, "text/plain", b"safe", limits)
+                .unwrap();
+        }
+    }
+
+    #[test]
+    fn paste_artifact_limits_and_corruption_fail_closed() {
+        let tmp = tempfile::TempDir::new().unwrap();
+        let store = FsStore::new(tmp.path()).unwrap();
+        let session_id = new_session_id();
+        let limits = PasteArtifactLimits {
+            max_artifact_bytes: 5,
+            max_session_bytes: 8,
+            max_session_artifacts: 2,
+        };
+        let first = store
+            .write_paste_artifact(session_id, "entry-1", "1234", limits)
+            .unwrap();
+        assert!(matches!(
+            store.write_paste_artifact(session_id, "entry-2", "56789", limits),
+            Err(StoreError::PasteArtifactLimit(_))
+        ));
+        assert!(matches!(
+            store.write_paste_artifact(session_id, "entry-2", "5678", limits),
+            Ok(_)
+        ));
+        std::fs::write(
+            store.paste_artifact_path(session_id, &first.artifact_id),
+            b"{}",
+        )
+        .unwrap();
+        assert!(matches!(
+            store.read_paste_artifact(session_id, &first.artifact_id),
+            Err(StoreError::Serde(_)) | Err(StoreError::PasteArtifactIntegrity(_))
+        ));
+    }
 }
@@ -0,0 +1,165 @@
+//! Serializable history entries with restore-authoritative logical identity and origin.
+
+use serde::{Deserialize, Serialize};
+
+use crate::LoggedItem;
+
+/// Stable logical identity of one model-visible history entry.
+///
+/// This value is generated at the trusted Worker session boundary and copied
+/// unchanged across fork, rewind, compaction retention, restore, and reboot.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[serde(transparent)]
+pub struct LoggedSessionHistoryEntryId(pub String);
+
+impl LoggedSessionHistoryEntryId {
+    pub fn new() -> Self {
+        Self(uuid::Uuid::now_v7().to_string())
+    }
+}
+
+impl Default for LoggedSessionHistoryEntryId {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Bounded subject snapshot. It is evidence, not a live authorization handle.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct LoggedWorkerSubject {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub workspace_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub runtime_id: Option<String>,
+    pub worker_id: String,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum LoggedSessionHistoryOrigin {
+    HumanInput {
+        account_id: String,
+    },
+    WorkerInput {
+        actor: LoggedWorkerSubject,
+    },
+    FlowInstruction {
+        selector: String,
+        definition_id: String,
+        definition_revision: u64,
+        instance_id: String,
+        state_id: String,
+    },
+    BackendInstruction {
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        operation_id: Option<String>,
+    },
+    ModelOutput {
+        worker: LoggedWorkerSubject,
+    },
+    ToolOutput {
+        worker: LoggedWorkerSubject,
+    },
+    DerivedSummary,
+    LegacyUnknown,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct LoggedHistoryDerivation {
+    pub sources: Vec<LoggedSessionHistoryEntryId>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct LoggedSessionHistoryMetadata {
+    pub entry_id: LoggedSessionHistoryEntryId,
+    pub origin: LoggedSessionHistoryOrigin,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub derivation: Option<LoggedHistoryDerivation>,
+}
+
+impl LoggedSessionHistoryMetadata {
+    pub fn legacy_unknown() -> Self {
+        Self {
+            entry_id: LoggedSessionHistoryEntryId::new(),
+            origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+            derivation: None,
+        }
+    }
+}
+
+/// Persisted item and metadata are one value so transforms cannot reorder or
+/// truncate one without the other.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct LoggedHistoryEntry {
+    pub item: LoggedItem,
+    pub metadata: LoggedSessionHistoryMetadata,
+}
+
+/// Typed system-item history record. The typed system event remains available
+/// to client replay while its model-visible projection carries the same stable
+/// metadata used by live history.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct LoggedSystemHistoryEntry {
+    pub item: crate::SystemItem,
+    pub metadata: LoggedSessionHistoryMetadata,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::LoggedRole;
+    use agen::llm_client::RequestConfig;
+
+    #[test]
+    fn logged_history_entry_round_trip_preserves_id_origin_and_derivation() {
+        let source_id = LoggedSessionHistoryEntryId::new();
+        let entry = LoggedHistoryEntry {
+            item: LoggedItem::Message {
+                role: LoggedRole::User,
+                content: vec![crate::LoggedContentPart::Text {
+                    text: "preference".into(),
+                }],
+            },
+            metadata: LoggedSessionHistoryMetadata {
+                entry_id: LoggedSessionHistoryEntryId::new(),
+                origin: LoggedSessionHistoryOrigin::HumanInput {
+                    account_id: "account-1".into(),
+                },
+                derivation: Some(LoggedHistoryDerivation {
+                    sources: vec![source_id.clone()],
+                }),
+            },
+        };
+        let encoded = serde_json::to_vec(&entry).unwrap();
+        let decoded: LoggedHistoryEntry = serde_json::from_slice(&encoded).unwrap();
+        assert_eq!(decoded, entry);
+        assert_eq!(
+            decoded.metadata.derivation.unwrap().sources,
+            vec![source_id]
+        );
+    }
+
+    #[test]
+    fn annotated_segment_start_is_restore_visible_without_projecting_metadata() {
+        let session_id = uuid::Uuid::now_v7();
+        let history_entry = LoggedHistoryEntry {
+            item: LoggedItem::Message {
+                role: LoggedRole::Assistant,
+                content: vec![crate::LoggedContentPart::Text {
+                    text: "answer".into(),
+                }],
+            },
+            metadata: LoggedSessionHistoryMetadata::legacy_unknown(),
+        };
+        let state = crate::collect_state(&[crate::LogEntry::AnnotatedSegmentStart {
+            ts: 1,
+            session_id,
+            system_prompt: None,
+            config: RequestConfig::default(),
+            history: vec![history_entry],
+            forked_from: None,
+            compacted_from: None,
+        }]);
+        assert_eq!(state.history[0].as_text(), Some("answer"));
+    }
+}
@@ -0,0 +1,188 @@
+//! Versioned decoder for Session schemas that predate canonical annotated history.
+//!
+//! These types are intentionally private to `session-store`. Current writers,
+//! replay, and public projections use [`crate::LogEntry`] exclusively; only the
+//! Worker Session schema migration is allowed to deserialize these shapes.
+
+use agen::llm_client::types::RequestConfig;
+use protocol::Segment;
+use serde::Deserialize;
+
+use crate::{
+    LogEntry, LoggedHistoryEntry, LoggedItem, LoggedSessionHistoryEntryId,
+    LoggedSessionHistoryMetadata, LoggedSessionHistoryOrigin, LoggedSystemHistoryEntry, SegmentId,
+    SegmentOrigin, SessionExtension, SessionId, SystemItem,
+};
+
+#[derive(Debug, Deserialize)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+enum LegacyHistoryLogEntry {
+    SegmentStart {
+        ts: u64,
+        session_id: SessionId,
+        system_prompt: Option<String>,
+        config: RequestConfig,
+        history: Vec<LoggedItem>,
+        #[serde(default)]
+        forked_from: Option<SegmentOrigin>,
+        #[serde(default)]
+        compacted_from: Option<SegmentOrigin>,
+    },
+    UserInput {
+        ts: u64,
+        segments: Vec<Segment>,
+        #[serde(default)]
+        extensions: Vec<SessionExtension>,
+    },
+    AssistantItem {
+        ts: u64,
+        item: LoggedItem,
+    },
+    ToolResult {
+        ts: u64,
+        item: LoggedItem,
+    },
+    SystemItem {
+        ts: u64,
+        item: SystemItem,
+    },
+}
+
+/// Schema-v1 decoder. Non-history records already had their current shape, so
+/// they pass through `LogEntry`; legacy history records are converted below.
+#[derive(Debug, Deserialize)]
+#[serde(untagged)]
+enum LegacySessionLogEntryV1 {
+    History(LegacyHistoryLogEntry),
+    Current(LogEntry),
+}
+
+/// Schema v2 retained the v1 history shapes while adding non-history records.
+/// Keep a distinct type so supported source versions remain explicit rather
+/// than turning migration compatibility into the current `LogEntry` contract.
+#[derive(Debug, Deserialize)]
+#[serde(untagged)]
+enum LegacySessionLogEntryV2 {
+    History(LegacyHistoryLogEntry),
+    Current(LogEntry),
+}
+
+pub(crate) fn decode_entry(
+    schema_version: u32,
+    line: &str,
+    session_id: SessionId,
+    segment_id: SegmentId,
+    line_index: usize,
+) -> Result<LogEntry, serde_json::Error> {
+    let entry = match schema_version {
+        1 => match serde_json::from_str::<LegacySessionLogEntryV1>(line)? {
+            LegacySessionLogEntryV1::History(entry) => Entry::History(entry),
+            LegacySessionLogEntryV1::Current(entry) => Entry::Current(entry),
+        },
+        2 => match serde_json::from_str::<LegacySessionLogEntryV2>(line)? {
+            LegacySessionLogEntryV2::History(entry) => Entry::History(entry),
+            LegacySessionLogEntryV2::Current(entry) => Entry::Current(entry),
+        },
+        _ => unreachable!("legacy decoder called for unsupported schema {schema_version}"),
+    };
+    Ok(match entry {
+        Entry::History(entry) => {
+            canonicalize_history_entry(session_id, segment_id, line_index, entry)
+        }
+        Entry::Current(entry) => entry,
+    })
+}
+
+enum Entry {
+    History(LegacyHistoryLogEntry),
+    Current(LogEntry),
+}
+
+fn legacy_metadata(
+    segment_id: SegmentId,
+    line_index: usize,
+    item_index: usize,
+) -> LoggedSessionHistoryMetadata {
+    let mut identity = Vec::with_capacity(32);
+    identity.extend_from_slice(segment_id.as_bytes());
+    identity.extend_from_slice(&(line_index as u64).to_be_bytes());
+    identity.extend_from_slice(&(item_index as u64).to_be_bytes());
+    LoggedSessionHistoryMetadata {
+        entry_id: LoggedSessionHistoryEntryId(format!(
+            "l-{}",
+            base64::Engine::encode(&base64::engine::general_purpose::URL_SAFE_NO_PAD, identity)
+        )),
+        origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+        derivation: None,
+    }
+}
+
+fn canonicalize_history_entry(
+    _session_id: SessionId,
+    segment_id: SegmentId,
+    line_index: usize,
+    entry: LegacyHistoryLogEntry,
+) -> LogEntry {
+    match entry {
+        LegacyHistoryLogEntry::SegmentStart {
+            ts,
+            session_id,
+            system_prompt,
+            config,
+            history,
+            forked_from,
+            compacted_from,
+        } => LogEntry::AnnotatedSegmentStart {
+            ts,
+            session_id,
+            system_prompt,
+            config,
+            history: history
+                .into_iter()
+                .enumerate()
+                .map(|(item_index, item)| LoggedHistoryEntry {
+                    item,
+                    metadata: legacy_metadata(segment_id, line_index, item_index),
+                })
+                .collect(),
+            forked_from,
+            compacted_from,
+        },
+        LegacyHistoryLogEntry::UserInput {
+            ts,
+            segments,
+            extensions,
+        } => LogEntry::AnnotatedUserInput {
+            ts,
+            history: vec![LoggedHistoryEntry {
+                item: LoggedItem::from(agen::Item::user_message(Segment::flatten_to_text(
+                    &segments,
+                ))),
+                metadata: legacy_metadata(segment_id, line_index, 0),
+            }],
+            segments,
+            extensions,
+        },
+        LegacyHistoryLogEntry::AssistantItem { ts, item } => LogEntry::AnnotatedAssistantItem {
+            ts,
+            entry: LoggedHistoryEntry {
+                item,
+                metadata: legacy_metadata(segment_id, line_index, 0),
+            },
+        },
+        LegacyHistoryLogEntry::ToolResult { ts, item } => LogEntry::AnnotatedToolResult {
+            ts,
+            entry: LoggedHistoryEntry {
+                item,
+                metadata: legacy_metadata(segment_id, line_index, 0),
+            },
+        },
+        LegacyHistoryLogEntry::SystemItem { ts, item } => LogEntry::AnnotatedSystemItem {
+            ts,
+            entry: LoggedSystemHistoryEntry {
+                item,
+                metadata: legacy_metadata(segment_id, line_index, 0),
+            },
+        },
+    }
+}
@@ -26,17 +26,23 @@
 //! let (session_id, segment_id) = create_segment(&store, SegmentStartState {
 //!     system_prompt: None,
 //!     config: &config,
-//!     history: &[],
+//!     history: Vec::new(),
+//!     user_segments: Vec::new(),
 //! })?;
 //! ```

 pub mod event_trace;
 pub mod fs_store;
+pub mod history;
+mod legacy_session_log;
 pub mod logged_item;
+mod paste_artifact;
+pub mod public_snapshot;
 pub mod segment;
 pub mod segment_log;
 pub mod store;
 pub mod system_item;
+pub mod uploaded_file;
 pub mod worker_metadata;
 pub mod worker_session_store;

@@ -44,9 +50,15 @@ pub use agen::UsageRecord;
 pub use agen::llm_client::types::{ContentPart, Item, Role};
 pub use event_trace::{TraceEntry, TracePayload};
 pub use fs_store::FsStore;
+pub use history::{
+    LoggedHistoryDerivation, LoggedHistoryEntry, LoggedSessionHistoryEntryId,
+    LoggedSessionHistoryMetadata, LoggedSessionHistoryOrigin, LoggedSystemHistoryEntry,
+    LoggedWorkerSubject,
+};
 pub use logged_item::{LoggedContentPart, LoggedItem, LoggedRole, from_logged, to_logged};
+pub use paste_artifact::PasteArtifactLimits;
 pub use segment::{
-    SegmentStartState, append_entry, append_system_item, classify_history_item,
+    SegmentStartState, append_entry, append_system_item, classify_logged_history_entry,
    create_compacted_segment, create_segment, create_segment_with_ids, ensure_head_or_fork, fork,
    fork_at, restore, restore_by_segment, save_config_changed, save_delta, save_extension,
    save_run_completed, save_run_errored, save_turn_end, save_usage, save_user_input,
@@ -56,6 +68,11 @@ pub use store::{Store, StoreError};
 pub use system_item::{
    PromptRenderProvenance, SystemItem, SystemReminder, SystemReminderSource, render_worker_event,
 };
+pub use uploaded_file::{
+    DEFAULT_MAX_FILES_PER_SUBMISSION, DEFAULT_MAX_SESSION_ARTIFACT_BYTES,
+    DEFAULT_MAX_SESSION_UPLOADED_FILES, DEFAULT_MAX_UPLOADED_FILE_BYTES, UploadedFileLimits,
+    UploadedFileUploadContext,
+};
 pub use worker_metadata::{
    CombinedStore, FsWorkerStore, WorkerActiveSegmentRef, WorkerAggregateStore, WorkerMetadata,
    WorkerMetadataStore, WorkerPeer, WorkerReclaimedChild, WorkerSpawnedChild,
@@ -14,7 +14,7 @@

 use agen::{
    llm_client::types::{ContentPart, Item, Role},
-    tool::{Attachment, ImageAttachment},
+    tool::{Attachment, ImageAttachment, ToolResultDisposition},
 };
 use base64::{Engine as _, engine::general_purpose::STANDARD};
 use serde::{Deserialize, Deserializer, Serialize, Serializer, de::Error as _};
@@ -61,6 +61,8 @@ pub enum LoggedItem {
        content: Option<String>,
        #[serde(default, skip_serializing_if = "Vec::is_empty")]
        attachments: Vec<LoggedAttachment>,
+        #[serde(default, skip_serializing_if = "ToolResultDisposition::is_success")]
+        disposition: ToolResultDisposition,
        #[serde(default, skip_serializing_if = "is_false")]
        is_error: bool,
    },
@@ -128,6 +130,7 @@ impl From<&Item> for LoggedItem {
                summary,
                content,
                attachments,
+                disposition,
                is_error,
                ..
            } => Self::ToolResult {
@@ -135,6 +138,7 @@ impl From<&Item> for LoggedItem {
                summary: summary.clone(),
                content: content.clone(),
                attachments: attachments.iter().map(LoggedAttachment::from).collect(),
+                disposition: *disposition,
                is_error: *is_error,
            },
            Item::Reasoning {
@@ -184,15 +188,24 @@ impl From<LoggedItem> for Item {
                summary,
                content,
                attachments,
+                disposition,
                is_error,
-            } => Item::ToolResult {
+            } => {
+                let disposition = if is_error && disposition.is_success() {
+                    ToolResultDisposition::Error
+                } else {
+                    disposition
+                };
+                Item::ToolResult {
                    id: None,
                    call_id,
                    summary,
                    content,
+                    disposition,
                    is_error,
                    attachments: attachments.into_iter().map(Attachment::from).collect(),
-            },
+                }
+            }
            LoggedItem::Reasoning {
                text,
                summary,
@@ -430,6 +443,42 @@ mod tests {
        }
    }

+    #[test]
+    fn outcome_unknown_tool_result_round_trips_as_terminal() {
+        let original = Item::tool_result_item_with_disposition_and_attachments(
+            "call_unknown",
+            "outcome unknown",
+            Some("bounded progress".to_string()),
+            ToolResultDisposition::OutcomeUnknown,
+            Vec::new(),
+        );
+        let logged: LoggedItem = (&original).into();
+        let json = serde_json::to_string(&logged).unwrap();
+        assert!(json.contains(r#""disposition":"outcome_unknown""#));
+        match Item::from(serde_json::from_str::<LoggedItem>(&json).unwrap()) {
+            Item::ToolResult {
+                disposition,
+                is_error,
+                ..
+            } => {
+                assert_eq!(disposition, ToolResultDisposition::OutcomeUnknown);
+                assert!(is_error);
+            }
+            other => panic!("unexpected variant: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn legacy_error_tool_result_infers_error_disposition() {
+        let legacy = r#"{"kind":"tool_result","call_id":"call_old","summary":"failed","content":null,"is_error":true}"#;
+        match Item::from(serde_json::from_str::<LoggedItem>(legacy).unwrap()) {
+            Item::ToolResult { disposition, .. } => {
+                assert_eq!(disposition, ToolResultDisposition::Error)
+            }
+            other => panic!("unexpected variant: {other:?}"),
+        }
+    }
+
    #[test]
    fn tool_result_persistence_round_trips_binary_attachments() {
        let original = Item::tool_result_item_with_attachments(
@@ -0,0 +1,205 @@
+//! Session-owned storage for large pasted-input artifacts.
+
+use std::fs;
+use std::io::Write as _;
+use std::path::Path;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use fs4::fs_std::FileExt;
+use protocol::{PasteArtifactAvailability, PasteArtifactMediaType, PasteArtifactRef};
+use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
+
+use crate::StoreError;
+
+/// Bounded storage policy applied before a large paste becomes durable input.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct PasteArtifactLimits {
+    pub max_artifact_bytes: u64,
+    pub max_session_bytes: u64,
+    pub max_session_artifacts: u64,
+}
+
+impl Default for PasteArtifactLimits {
+    fn default() -> Self {
+        Self {
+            max_artifact_bytes: 8 * 1024 * 1024,
+            max_session_bytes: 64 * 1024 * 1024,
+            max_session_artifacts: 1_024,
+        }
+    }
+}
+
+/// Integrity-bearing on-disk record. The body and metadata are committed in one
+/// atomic file replacement so readers never observe a half-written artifact.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub(crate) struct StoredPasteArtifact {
+    pub reference: PasteArtifactRef,
+    pub content: String,
+}
+
+pub(crate) fn stored_paste_usage(artifact_dir: &Path) -> Result<(u64, u64), StoreError> {
+    if !artifact_dir.exists() {
+        return Ok((0, 0));
+    }
+    let mut aggregate = 0_u64;
+    let mut artifact_count = 0_u64;
+    for entry in fs::read_dir(artifact_dir)? {
+        let path = entry?.path();
+        let Some(name) = path.file_name().and_then(|value| value.to_str()) else {
+            continue;
+        };
+        if !name.ends_with(".json") || name.ends_with(".file.json") {
+            continue;
+        }
+        let stored: StoredPasteArtifact = serde_json::from_slice(&fs::read(&path)?)?;
+        verify(&stored, &stored.reference.artifact_id)?;
+        artifact_count = artifact_count.checked_add(1).ok_or_else(|| {
+            StoreError::PasteArtifactLimit("session artifact count overflow".to_string())
+        })?;
+        aggregate = aggregate
+            .checked_add(stored.reference.byte_len)
+            .ok_or_else(|| {
+                StoreError::PasteArtifactLimit("session aggregate size overflow".to_string())
+            })?;
+    }
+    Ok((aggregate, artifact_count))
+}
+
+pub(crate) fn write_to_dir(
+    artifact_dir: &Path,
+    source_entry_id: &str,
+    content: &str,
+    limits: PasteArtifactLimits,
+) -> Result<PasteArtifactRef, StoreError> {
+    let byte_len = content.len() as u64;
+    if byte_len > limits.max_artifact_bytes {
+        return Err(StoreError::PasteArtifactLimit(format!(
+            "artifact has {byte_len} bytes; maximum is {}",
+            limits.max_artifact_bytes
+        )));
+    }
+    fs::create_dir_all(artifact_dir)?;
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(artifact_dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let (paste_bytes, artifact_count) = stored_paste_usage(artifact_dir)?;
+    let (uploaded_bytes, uploaded_count) =
+        crate::uploaded_file::stored_uploaded_file_usage(artifact_dir)?;
+    let aggregate = paste_bytes.checked_add(uploaded_bytes).ok_or_else(|| {
+        StoreError::PasteArtifactLimit("session aggregate size overflow".to_string())
+    })?;
+    let artifact_count = artifact_count.checked_add(uploaded_count).ok_or_else(|| {
+        StoreError::PasteArtifactLimit("session artifact count overflow".to_string())
+    })?;
+    let projected = aggregate.checked_add(byte_len).ok_or_else(|| {
+        StoreError::PasteArtifactLimit("session aggregate size overflow".to_string())
+    })?;
+    if projected > limits.max_session_bytes {
+        return Err(StoreError::PasteArtifactLimit(format!(
+            "session artifacts would use {projected} bytes; maximum is {}",
+            limits.max_session_bytes
+        )));
+    }
+    if artifact_count >= limits.max_session_artifacts {
+        return Err(StoreError::PasteArtifactLimit(format!(
+            "session already has {artifact_count} artifacts; maximum is {}",
+            limits.max_session_artifacts
+        )));
+    }
+
+    let artifact_id = uuid::Uuid::now_v7().to_string();
+    let created_at_ms = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_err(|error| StoreError::PasteArtifactIntegrity(error.to_string()))?
+        .as_millis() as u64;
+    let reference = PasteArtifactRef {
+        artifact_id: artifact_id.clone(),
+        created_at_ms,
+        media_type: PasteArtifactMediaType::TextPlainUtf8,
+        availability: PasteArtifactAvailability::Available,
+        byte_len,
+        char_count: content.chars().count() as u64,
+        line_count: line_count(content),
+        sha256: sha256_hex(content),
+        source_entry_id: source_entry_id.to_string(),
+    };
+    let bytes = serde_json::to_vec(&StoredPasteArtifact {
+        reference: reference.clone(),
+        content: content.to_string(),
+    })?;
+    let target = artifact_dir.join(format!("{artifact_id}.json"));
+    let temporary = artifact_dir.join(format!(".{artifact_id}.tmp"));
+    let mut file = fs::OpenOptions::new()
+        .create_new(true)
+        .write(true)
+        .open(&temporary)?;
+    if let Err(error) = file.write_all(&bytes).and_then(|_| file.sync_all()) {
+        let _ = fs::remove_file(&temporary);
+        return Err(error.into());
+    }
+    if let Err(error) = fs::rename(&temporary, &target) {
+        let _ = fs::remove_file(&temporary);
+        return Err(error.into());
+    }
+    if let Ok(directory) = fs::File::open(artifact_dir) {
+        directory.sync_all()?;
+    }
+    Ok(reference)
+}
+
+pub(crate) fn read_from_dir(
+    artifact_dir: &Path,
+    artifact_id: &str,
+) -> Result<(PasteArtifactRef, String), StoreError> {
+    let parsed = uuid::Uuid::parse_str(artifact_id)
+        .map_err(|_| StoreError::PasteArtifactNotFound(artifact_id.to_string()))?;
+    if parsed.to_string() != artifact_id {
+        return Err(StoreError::PasteArtifactNotFound(artifact_id.to_string()));
+    }
+    let path = artifact_dir.join(format!("{artifact_id}.json"));
+    let bytes = match fs::read(path) {
+        Ok(bytes) => bytes,
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => {
+            return Err(StoreError::PasteArtifactNotFound(artifact_id.to_string()));
+        }
+        Err(error) => return Err(error.into()),
+    };
+    let stored: StoredPasteArtifact = serde_json::from_slice(&bytes)?;
+    verify(&stored, artifact_id)?;
+    Ok((stored.reference, stored.content))
+}
+
+fn verify(stored: &StoredPasteArtifact, artifact_id: &str) -> Result<(), StoreError> {
+    let actual_digest = sha256_hex(&stored.content);
+    if stored.reference.artifact_id != artifact_id
+        || stored.reference.created_at_ms == 0
+        || stored.reference.media_type != PasteArtifactMediaType::TextPlainUtf8
+        || stored.reference.availability != PasteArtifactAvailability::Available
+        || stored.reference.byte_len != stored.content.len() as u64
+        || stored.reference.char_count != stored.content.chars().count() as u64
+        || stored.reference.line_count != line_count(&stored.content)
+        || stored.reference.sha256 != actual_digest
+    {
+        return Err(StoreError::PasteArtifactIntegrity(artifact_id.to_string()));
+    }
+    Ok(())
+}
+
+fn sha256_hex(content: &str) -> String {
+    Sha256::digest(content.as_bytes())
+        .iter()
+        .map(|byte| format!("{byte:02x}"))
+        .collect()
+}
+
+fn line_count(content: &str) -> u64 {
+    if content.is_empty() {
+        0
+    } else {
+        content.lines().count().max(1) as u64
+    }
+}
@@ -0,0 +1,559 @@
+use base64::{
+    Engine as _,
+    engine::general_purpose::{STANDARD as BASE64, URL_SAFE_NO_PAD},
+};
+use protocol::{
+    Segment, SessionContentPart, SessionEntryProvenance, SessionMessageRole, SessionSnapshot,
+    SessionSnapshotEntry, SessionSnapshotEntryData, SessionToolAttachment,
+};
+
+use crate::{
+    LogEntry, LoggedContentPart, LoggedHistoryEntry, LoggedItem, LoggedRole,
+    LoggedSessionHistoryOrigin, SessionId, SystemItem,
+};
+
+/// Project a complete current-segment log. A valid segment starts with one
+/// canonical annotated SegmentStart record; malformed partial input uses the
+/// nil session only to keep the public failure projection deterministic.
+pub fn project_current_session_snapshot(log: &[LogEntry]) -> SessionSnapshot {
+    let session_id = log.iter().find_map(|entry| match entry {
+        LogEntry::AnnotatedSegmentStart { session_id, .. } => Some(*session_id),
+        _ => None,
+    });
+    project_session_snapshot(session_id.unwrap_or_else(SessionId::nil), log)
+}
+
+/// Project the current durable segment into the only public session-history
+/// representation. Append-log records remain an internal persistence format.
+pub fn project_session_snapshot(session_id: SessionId, log: &[LogEntry]) -> SessionSnapshot {
+    let mut session_key = session_id;
+    let mut entries = Vec::new();
+
+    for (log_index, record) in log.iter().enumerate() {
+        match record {
+            LogEntry::AnnotatedSegmentStart {
+                ts,
+                session_id,
+                history,
+                ..
+            } => {
+                session_key = *session_id;
+                entries.clear();
+                extend_history(&mut entries, history, None, *ts);
+            }
+            LogEntry::InputSegmentsCheckpoint { user_segments, .. } => {
+                let mut segments = user_segments.iter();
+                for entry in &mut entries {
+                    let is_user = matches!(
+                        &entry.data,
+                        SessionSnapshotEntryData::UserInput { .. }
+                            | SessionSnapshotEntryData::Message {
+                                role: SessionMessageRole::User,
+                                ..
+                            }
+                    );
+                    if is_user && let Some(checkpoint) = segments.next() {
+                        entry.data = SessionSnapshotEntryData::UserInput {
+                            segments: checkpoint.clone(),
+                        };
+                    }
+                }
+            }
+            LogEntry::AnnotatedUserInput {
+                ts,
+                segments,
+                history,
+                ..
+            } => extend_history(&mut entries, history, Some(segments), *ts),
+            LogEntry::AnnotatedAssistantItem { ts, entry }
+            | LogEntry::AnnotatedToolResult { ts, entry } => {
+                if let Some(data) = project_item(&entry.item) {
+                    entries.push(history_entry(entry, *ts, data));
+                }
+            }
+            LogEntry::AnnotatedSystemItem { ts, entry } => entries.push(system_entry(
+                &entry.item,
+                entry.metadata.entry_id.0.clone(),
+                *ts,
+                provenance(&entry.metadata.origin),
+                derivation_ids(entry),
+            )),
+            LogEntry::RunErrored { ts, message, .. } => entries.push(legacy_entry(
+                &session_key,
+                log_index,
+                0,
+                *ts,
+                SessionSnapshotEntryData::RunError {
+                    message: message.clone(),
+                },
+            )),
+            // Run checkpoints, configuration, usage, and extension state are
+            // controller/storage authority rather than committed conversation.
+            LogEntry::Invoke { .. }
+            | LogEntry::TurnEnd { .. }
+            | LogEntry::RunCompleted { .. }
+            | LogEntry::ActiveRunCheckpoint { .. }
+            | LogEntry::PausedTurnAbandoned { .. }
+            | LogEntry::ConfigChanged { .. }
+            | LogEntry::LlmUsage { .. }
+            | LogEntry::Extension { .. } => {}
+        }
+    }
+
+    SessionSnapshot { entries }
+}
+
+fn extend_history(
+    output: &mut Vec<SessionSnapshotEntry>,
+    history: &[LoggedHistoryEntry],
+    input_segments: Option<&Vec<Segment>>,
+    timestamp: u64,
+) {
+    let mut attached_segments = false;
+    for entry in history {
+        let data = if !attached_segments
+            && input_segments.is_some()
+            && matches!(
+                &entry.item,
+                LoggedItem::Message {
+                    role: LoggedRole::User,
+                    ..
+                }
+            ) {
+            attached_segments = true;
+            SessionSnapshotEntryData::UserInput {
+                segments: input_segments.cloned().unwrap_or_default(),
+            }
+        } else {
+            let Some(data) = project_item(&entry.item) else {
+                continue;
+            };
+            data
+        };
+        output.push(history_entry(entry, timestamp, data));
+    }
+}
+
+fn history_entry(
+    entry: &LoggedHistoryEntry,
+    timestamp: u64,
+    data: SessionSnapshotEntryData,
+) -> SessionSnapshotEntry {
+    SessionSnapshotEntry {
+        entry_id: entry.metadata.entry_id.0.clone(),
+        timestamp,
+        provenance: provenance(&entry.metadata.origin),
+        derived_from: entry
+            .metadata
+            .derivation
+            .as_ref()
+            .map(|derivation| {
+                derivation
+                    .sources
+                    .iter()
+                    .map(|source| source.0.clone())
+                    .collect()
+            })
+            .unwrap_or_default(),
+        data,
+    }
+}
+
+fn derivation_ids(entry: &crate::LoggedSystemHistoryEntry) -> Vec<String> {
+    entry
+        .metadata
+        .derivation
+        .as_ref()
+        .map(|derivation| {
+            derivation
+                .sources
+                .iter()
+                .map(|source| source.0.clone())
+                .collect()
+        })
+        .unwrap_or_default()
+}
+
+fn legacy_entry(
+    session_key: &SessionId,
+    log_index: usize,
+    item_index: usize,
+    timestamp: u64,
+    data: SessionSnapshotEntryData,
+) -> SessionSnapshotEntry {
+    SessionSnapshotEntry {
+        entry_id: legacy_entry_id(session_key, log_index, item_index),
+        timestamp,
+        provenance: SessionEntryProvenance::LegacyUnknown,
+        derived_from: Vec::new(),
+        data,
+    }
+}
+
+fn legacy_entry_id(session_key: &SessionId, log_index: usize, item_index: usize) -> String {
+    let mut identity = Vec::with_capacity(32);
+    identity.extend_from_slice(session_key.as_bytes());
+    identity.extend_from_slice(&(log_index as u64).to_be_bytes());
+    identity.extend_from_slice(&(item_index as u64).to_be_bytes());
+    format!("l-{}", URL_SAFE_NO_PAD.encode(identity))
+}
+
+fn provenance(origin: &LoggedSessionHistoryOrigin) -> SessionEntryProvenance {
+    match origin {
+        LoggedSessionHistoryOrigin::HumanInput { .. } => SessionEntryProvenance::HumanInput,
+        LoggedSessionHistoryOrigin::WorkerInput { .. } => SessionEntryProvenance::WorkerInput,
+        LoggedSessionHistoryOrigin::FlowInstruction { .. } => {
+            SessionEntryProvenance::FlowInstruction
+        }
+        LoggedSessionHistoryOrigin::BackendInstruction { .. } => {
+            SessionEntryProvenance::BackendInstruction
+        }
+        LoggedSessionHistoryOrigin::ModelOutput { .. } => SessionEntryProvenance::ModelOutput,
+        LoggedSessionHistoryOrigin::ToolOutput { .. } => SessionEntryProvenance::ToolOutput,
+        LoggedSessionHistoryOrigin::DerivedSummary => SessionEntryProvenance::DerivedSummary,
+        LoggedSessionHistoryOrigin::LegacyUnknown => SessionEntryProvenance::LegacyUnknown,
+    }
+}
+
+fn project_item(item: &LoggedItem) -> Option<SessionSnapshotEntryData> {
+    match item {
+        LoggedItem::Message { role, content } => {
+            let role = match role {
+                LoggedRole::User => SessionMessageRole::User,
+                LoggedRole::Assistant => SessionMessageRole::Assistant,
+                // System prompts and instruction history never cross the public
+                // snapshot boundary. Typed SystemItems have separate records.
+                LoggedRole::System => return None,
+            };
+            Some(SessionSnapshotEntryData::Message {
+                role,
+                content: content
+                    .iter()
+                    .map(|part| match part {
+                        LoggedContentPart::Text { text } => {
+                            SessionContentPart::Text { text: text.clone() }
+                        }
+                        LoggedContentPart::Refusal { refusal } => SessionContentPart::Refusal {
+                            refusal: refusal.clone(),
+                        },
+                    })
+                    .collect(),
+            })
+        }
+        LoggedItem::ToolCall {
+            call_id,
+            name,
+            arguments,
+        } => Some(SessionSnapshotEntryData::ToolCall {
+            call_id: call_id.clone(),
+            name: name.clone(),
+            arguments: arguments.clone(),
+        }),
+        LoggedItem::ToolResult {
+            call_id,
+            summary,
+            content,
+            is_error,
+            attachments,
+            ..
+        } => Some(SessionSnapshotEntryData::ToolResult {
+            call_id: call_id.clone(),
+            summary: summary.clone(),
+            content: content.clone(),
+            is_error: *is_error,
+            attachments: attachments
+                .iter()
+                .map(|attachment| match attachment {
+                    crate::logged_item::LoggedAttachment::Image { mime_type, data } => {
+                        SessionToolAttachment {
+                            media_type: mime_type.clone(),
+                            data_base64: BASE64.encode(data),
+                        }
+                    }
+                })
+                .collect(),
+        }),
+        // Hidden model reasoning is never observable.
+        LoggedItem::Reasoning { .. } => None,
+    }
+}
+
+fn system_entry(
+    item: &SystemItem,
+    entry_id: String,
+    timestamp: u64,
+    provenance: SessionEntryProvenance,
+    derived_from: Vec<String>,
+) -> SessionSnapshotEntry {
+    let mut data = serde_json::to_value(item).ok();
+    if let Some(serde_json::Value::Object(object)) = data.as_mut() {
+        object.remove("prompt_provenance");
+    }
+    let item_kind = data
+        .as_ref()
+        .and_then(|value| value.get("kind"))
+        .and_then(serde_json::Value::as_str)
+        .unwrap_or("system_item")
+        .to_owned();
+    SessionSnapshotEntry {
+        entry_id,
+        timestamp,
+        provenance,
+        derived_from,
+        data: SessionSnapshotEntryData::SystemItem {
+            item_kind,
+            content: item.history_text(),
+            data,
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use agen::llm_client::RequestConfig;
+
+    use super::*;
+    use crate::{
+        LoggedHistoryDerivation, LoggedSessionHistoryEntryId, LoggedSessionHistoryMetadata,
+        LoggedWorkerSubject,
+    };
+
+    #[test]
+    fn current_projection_is_stable_and_hides_reasoning_and_system_prompts() {
+        let session_id = crate::new_session_id();
+        let log = vec![LogEntry::AnnotatedSegmentStart {
+            ts: 1,
+            session_id,
+            system_prompt: None,
+            config: RequestConfig::default(),
+            history: vec![
+                LoggedItem::Message {
+                    role: LoggedRole::System,
+                    content: vec![LoggedContentPart::Text {
+                        text: "secret prompt".into(),
+                    }],
+                },
+                LoggedItem::Reasoning {
+                    text: "secret reasoning".into(),
+                    summary: Vec::new(),
+                    encrypted_content: None,
+                    signature: None,
+                },
+                LoggedItem::Message {
+                    role: LoggedRole::Assistant,
+                    content: vec![LoggedContentPart::Text {
+                        text: "visible".into(),
+                    }],
+                },
+            ]
+            .into_iter()
+            .map(|item| LoggedHistoryEntry {
+                item,
+                metadata: LoggedSessionHistoryMetadata {
+                    entry_id: LoggedSessionHistoryEntryId::new(),
+                    origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+                    derivation: None,
+                },
+            })
+            .collect(),
+            forked_from: None,
+            compacted_from: None,
+        }];
+
+        let first = project_session_snapshot(session_id, &log);
+        let second = project_session_snapshot(session_id, &log);
+        assert_eq!(first, second);
+        assert_eq!(first.entries.len(), 1);
+        assert_eq!(first.entries[0].timestamp, 1);
+        assert_eq!(
+            first.entries[0].provenance,
+            SessionEntryProvenance::LegacyUnknown
+        );
+        let json = serde_json::to_string(&first).unwrap();
+        assert!(!json.contains("secret prompt"));
+        assert!(!json.contains("secret reasoning"));
+        assert!(json.contains("visible"));
+    }
+
+    #[test]
+    fn compacted_checkpoint_restores_uploaded_file_segments() {
+        let session_id = crate::new_session_id();
+        let user_entry_id = LoggedSessionHistoryEntryId::new();
+        let file = protocol::UploadedFileRef {
+            artifact_id: "019ca7c8-57b6-7f05-8edf-524147aba7b3".into(),
+            file_name: "notes.md".into(),
+            media_type: "text/markdown".into(),
+            created_at_ms: 7,
+            availability: protocol::UploadedFileAvailability::Available,
+            byte_len: 12,
+            sha256: "a".repeat(64),
+            source_entry_id: Some(user_entry_id.0.clone()),
+        };
+        let segment = Segment::UploadedFile { file };
+        let log = vec![
+            LogEntry::AnnotatedSegmentStart {
+                ts: 10,
+                session_id,
+                system_prompt: None,
+                config: RequestConfig::default(),
+                history: vec![LoggedHistoryEntry {
+                    item: LoggedItem::Message {
+                        role: LoggedRole::User,
+                        content: vec![LoggedContentPart::Text {
+                            text: "[Attached file: notes.md]".into(),
+                        }],
+                    },
+                    metadata: LoggedSessionHistoryMetadata {
+                        entry_id: user_entry_id,
+                        origin: LoggedSessionHistoryOrigin::HumanInput {
+                            account_id: "account-1".into(),
+                        },
+                        derivation: None,
+                    },
+                }],
+                forked_from: None,
+                compacted_from: Some(crate::SegmentOrigin {
+                    segment_id: crate::new_segment_id(),
+                    at_turn_index: 1,
+                }),
+            },
+            LogEntry::InputSegmentsCheckpoint {
+                ts: 10,
+                user_segments: vec![vec![segment.clone()]],
+            },
+        ];
+
+        let snapshot = project_current_session_snapshot(&log);
+        assert_eq!(
+            snapshot.entries[0].data,
+            SessionSnapshotEntryData::UserInput {
+                segments: vec![segment]
+            }
+        );
+    }
+
+    #[test]
+    fn annotated_user_input_attaches_segments_to_first_user_role_entry_for_any_origin() {
+        let session_id = crate::new_session_id();
+        let segments = vec![Segment::Text {
+            content: "normal submit".into(),
+        }];
+
+        for origin in [
+            LoggedSessionHistoryOrigin::LegacyUnknown,
+            LoggedSessionHistoryOrigin::FlowInstruction {
+                selector: "builtin:coder-review".into(),
+                definition_id: "flow-definition".into(),
+                definition_revision: 7,
+                instance_id: "flow-instance".into(),
+                state_id: "implement".into(),
+            },
+        ] {
+            let user_entry_id = LoggedSessionHistoryEntryId::new();
+            let source_entry_id = LoggedSessionHistoryEntryId::new();
+            let log = vec![
+                LogEntry::AnnotatedSegmentStart {
+                    ts: 1,
+                    session_id,
+                    system_prompt: None,
+                    config: RequestConfig::default(),
+                    history: Vec::new(),
+                    forked_from: None,
+                    compacted_from: None,
+                },
+                LogEntry::AnnotatedUserInput {
+                    ts: 2,
+                    segments: segments.clone(),
+                    history: vec![
+                        LoggedHistoryEntry {
+                            item: LoggedItem::Message {
+                                role: LoggedRole::System,
+                                content: vec![LoggedContentPart::Text {
+                                    text: "flow instruction".into(),
+                                }],
+                            },
+                            metadata: LoggedSessionHistoryMetadata {
+                                entry_id: LoggedSessionHistoryEntryId::new(),
+                                origin: LoggedSessionHistoryOrigin::FlowInstruction {
+                                    selector: "builtin:coder-review".into(),
+                                    definition_id: "flow-definition".into(),
+                                    definition_revision: 7,
+                                    instance_id: "flow-instance".into(),
+                                    state_id: "implement".into(),
+                                },
+                                derivation: None,
+                            },
+                        },
+                        LoggedHistoryEntry {
+                            item: LoggedItem::Message {
+                                role: LoggedRole::User,
+                                content: vec![LoggedContentPart::Text {
+                                    text: "normal submit".into(),
+                                }],
+                            },
+                            metadata: LoggedSessionHistoryMetadata {
+                                entry_id: user_entry_id.clone(),
+                                origin: origin.clone(),
+                                derivation: Some(LoggedHistoryDerivation {
+                                    sources: vec![source_entry_id.clone()],
+                                }),
+                            },
+                        },
+                    ],
+                    extensions: Vec::new(),
+                },
+            ];
+
+            let snapshot = project_current_session_snapshot(&log);
+            assert_eq!(snapshot.entries.len(), 1);
+            assert_eq!(snapshot.entries[0].entry_id, user_entry_id.0);
+            assert_eq!(snapshot.entries[0].provenance, provenance(&origin));
+            assert_eq!(snapshot.entries[0].derived_from, vec![source_entry_id.0]);
+            assert_eq!(
+                snapshot.entries[0].data,
+                SessionSnapshotEntryData::UserInput {
+                    segments: segments.clone(),
+                }
+            );
+        }
+    }
+
+    #[test]
+    fn annotated_projection_preserves_identity_and_provenance() {
+        let session_id = crate::new_session_id();
+        let metadata = LoggedSessionHistoryMetadata {
+            entry_id: LoggedSessionHistoryEntryId::new(),
+            origin: LoggedSessionHistoryOrigin::ModelOutput {
+                worker: LoggedWorkerSubject {
+                    workspace_id: None,
+                    runtime_id: None,
+                    worker_id: "worker".into(),
+                },
+            },
+            derivation: None,
+        };
+        let expected_id = metadata.entry_id.0.clone();
+        let log = vec![LogEntry::AnnotatedSegmentStart {
+            ts: 1,
+            session_id,
+            system_prompt: None,
+            config: RequestConfig::default(),
+            history: vec![LoggedHistoryEntry {
+                item: LoggedItem::Message {
+                    role: LoggedRole::Assistant,
+                    content: vec![LoggedContentPart::Text { text: "ok".into() }],
+                },
+                metadata,
+            }],
+            forked_from: None,
+            compacted_from: None,
+        }];
+
+        let snapshot = project_session_snapshot(session_id, &log);
+        assert_eq!(snapshot.entries[0].entry_id, expected_id);
+        assert_eq!(
+            snapshot.entries[0].provenance,
+            SessionEntryProvenance::ModelOutput
+        );
+    }
+}
@@ -4,11 +4,9 @@
 //! The caller (typically Worker) holds the Engine directly and calls these
 //! functions after state-mutating operations.

-use crate::logged_item::{LoggedItem, to_logged};
 use crate::segment_log::{self, LogEntry, SegmentOrigin};
 use crate::store::{Store, StoreError};
-use crate::system_item::SystemItem;
-use crate::{SegmentId, SessionId};
+use crate::{LoggedHistoryEntry, LoggedSystemHistoryEntry, SegmentId, SessionId};
 use agen::EngineResult;
 use agen::llm_client::RequestConfig;
 use agen::llm_client::types::Item;
@@ -18,7 +16,34 @@ use protocol::Segment;
 pub struct SegmentStartState<'a> {
    pub system_prompt: Option<&'a str>,
    pub config: &'a RequestConfig,
-    pub history: &'a [Item],
+    pub history: Vec<LoggedHistoryEntry>,
+    pub user_segments: Vec<Vec<Segment>>,
+}
+
+fn seed_entries(
+    ts: u64,
+    session_id: SessionId,
+    state: SegmentStartState<'_>,
+    forked_from: Option<SegmentOrigin>,
+    compacted_from: Option<SegmentOrigin>,
+) -> Vec<LogEntry> {
+    let entry = LogEntry::AnnotatedSegmentStart {
+        ts,
+        session_id,
+        system_prompt: state.system_prompt.map(String::from),
+        config: state.config.clone(),
+        history: state.history,
+        forked_from,
+        compacted_from,
+    };
+    let mut entries = vec![entry];
+    if !state.user_segments.is_empty() {
+        entries.push(LogEntry::InputSegmentsCheckpoint {
+            ts,
+            user_segments: state.user_segments,
+        });
+    }
+    entries
 }

 /// Create a new session + initial segment, writing the initial
@@ -44,16 +69,8 @@ pub fn create_segment_with_ids(
    segment_id: SegmentId,
    state: SegmentStartState<'_>,
 ) -> Result<(), StoreError> {
-    let entry = LogEntry::SegmentStart {
-        ts: segment_log::now_millis(),
-        session_id,
-        system_prompt: state.system_prompt.map(String::from),
-        config: state.config.clone(),
-        history: to_logged(state.history),
-        forked_from: None,
-        compacted_from: None,
-    };
-    store.append(session_id, segment_id, &entry)
+    let entries = seed_entries(segment_log::now_millis(), session_id, state, None, None);
+    store.create_segment(session_id, segment_id, &entries)
 }

 /// Create a compacted segment from an existing one. Inherits the source's
@@ -70,19 +87,17 @@ pub fn create_compacted_segment(
    source_turn_count: usize,
 ) -> Result<SegmentId, StoreError> {
    let segment_id = crate::new_segment_id();
-    let entry = LogEntry::SegmentStart {
-        ts: segment_log::now_millis(),
-        session_id: source_session_id,
-        system_prompt: state.system_prompt.map(String::from),
-        config: state.config.clone(),
-        history: to_logged(state.history),
-        forked_from: None,
-        compacted_from: Some(SegmentOrigin {
+    let entries = seed_entries(
+        segment_log::now_millis(),
+        source_session_id,
+        state,
+        None,
+        Some(SegmentOrigin {
            segment_id: source_segment_id,
            at_turn_index: source_turn_count,
        }),
-    };
-    store.append(source_session_id, segment_id, &entry)?;
+    );
+    store.create_segment(source_session_id, segment_id, &entries)?;
    Ok(segment_id)
 }

@@ -154,21 +169,19 @@ pub fn ensure_head_or_fork(
    }
    let source_segment_id = *segment_id;
    let fork_id = crate::new_segment_id();
-    let entry = LogEntry::SegmentStart {
-        ts: segment_log::now_millis(),
+    let entries = seed_entries(
+        segment_log::now_millis(),
        session_id,
-        system_prompt: state.system_prompt.map(String::from),
-        config: state.config.clone(),
-        history: to_logged(state.history),
-        forked_from: Some(SegmentOrigin {
+        state,
+        Some(SegmentOrigin {
            segment_id: source_segment_id,
            at_turn_index,
        }),
-        compacted_from: None,
-    };
-    store.create_segment(session_id, fork_id, &[entry])?;
+        None,
+    );
+    store.create_segment(session_id, fork_id, &entries)?;
    *segment_id = fork_id;
-    *entries_written = 1;
+    *entries_written = entries.len();
    Ok(())
 }

@@ -183,8 +196,9 @@ pub fn save_user_input(
    session_id: SessionId,
    segment_id: SegmentId,
    segments: Vec<Segment>,
+    history: Vec<LoggedHistoryEntry>,
 ) -> Result<(), StoreError> {
-    save_user_input_with_extensions(store, session_id, segment_id, segments, Vec::new())
+    save_user_input_with_extensions(store, session_id, segment_id, segments, history, Vec::new())
 }

 /// Atomically persist one typed user submission and Runtime-owned session
@@ -194,15 +208,17 @@ pub fn save_user_input_with_extensions(
    session_id: SessionId,
    segment_id: SegmentId,
    segments: Vec<Segment>,
+    history: Vec<LoggedHistoryEntry>,
    extensions: Vec<segment_log::SessionExtension>,
 ) -> Result<(), StoreError> {
    append_entry(
        store,
        session_id,
        segment_id,
-        LogEntry::UserInput {
+        LogEntry::AnnotatedUserInput {
            ts: segment_log::now_millis(),
            segments,
+            history,
            extensions,
        },
    )
@@ -220,64 +236,57 @@ pub fn save_delta(
    store: &impl Store,
    session_id: SessionId,
    segment_id: SegmentId,
-    new_items: &[Item],
+    new_items: &[LoggedHistoryEntry],
 ) -> Result<(), StoreError> {
    if new_items.is_empty() {
        return Ok(());
    }

    let ts = segment_log::now_millis();
-    for item in new_items {
+    for entry in new_items {
+        let item = Item::from(entry.item.clone());
        if item.is_user_message() {
            // Already persisted by save_user_input at submit time.
            continue;
        }
-        let entry = classify_history_item(item, ts);
+        let entry = classify_logged_history_entry(entry.clone(), ts);
        append_entry(store, session_id, segment_id, entry)?;
    }
    Ok(())
 }

-/// Map one history item to its singular `LogEntry` form. Used by the
-/// fallback `save_delta` path and the controller's worker-callback
-/// classifier so write classification lives in one place.
-pub fn classify_history_item(item: &Item, ts: u64) -> LogEntry {
+/// Map one annotated history entry to its singular `LogEntry` form. Used by
+/// the fallback `save_delta` path and the controller's worker-callback
+/// classifier so write classification lives in one place without discarding
+/// identity or provenance.
+/// Map one already-annotated history entry to its singular canonical record
+/// without changing its identity or provenance.
+pub fn classify_logged_history_entry(entry: LoggedHistoryEntry, ts: u64) -> LogEntry {
+    let item = Item::from(entry.item.clone());
    if item.is_tool_result() {
-        LogEntry::ToolResult {
-            ts,
-            item: LoggedItem::from(item),
-        }
-    } else if item.is_assistant_message() || item.is_tool_call() || item.is_reasoning() {
-        LogEntry::AssistantItem {
-            ts,
-            item: LoggedItem::from(item),
-        }
+        LogEntry::AnnotatedToolResult { ts, entry }
    } else {
-        // Defensive: anything else (future Item kinds) routes through
-        // AssistantItem rather than getting silently dropped.
-        LogEntry::AssistantItem {
-            ts,
-            item: LoggedItem::from(item),
-        }
+        // Assistant messages, tool calls, reasoning, and future non-user
+        // items all use the assistant-side canonical record.
+        LogEntry::AnnotatedAssistantItem { ts, entry }
    }
 }

-/// Append a single typed system item as `LogEntry::SystemItem`. Helper
-/// for the Worker-side interceptor commit path; mirrors the per-item
-/// commit shape used for assistant / tool result entries.
+/// Append one typed system item and its history metadata as a canonical
+/// `LogEntry::AnnotatedSystemItem`.
 pub fn append_system_item(
    store: &impl Store,
    session_id: SessionId,
    segment_id: SegmentId,
-    item: SystemItem,
+    entry: LoggedSystemHistoryEntry,
 ) -> Result<(), StoreError> {
    append_entry(
        store,
        session_id,
        segment_id,
-        LogEntry::SystemItem {
+        LogEntry::AnnotatedSystemItem {
            ts: segment_log::now_millis(),
-            item,
+            entry,
        },
    )
 }
@@ -307,6 +316,7 @@ pub fn save_run_completed(
    segment_id: SegmentId,
    result: EngineResult,
    interrupted: bool,
+    active_run_turn_count: Option<usize>,
 ) -> Result<(), StoreError> {
    append_entry(
        store,
@@ -316,6 +326,7 @@ pub fn save_run_completed(
            ts: segment_log::now_millis(),
            interrupted,
            result,
+            active_run_turn_count,
        },
    )
 }
@@ -424,20 +435,14 @@ pub fn save_config_changed(
 /// [`fork_at`] or [`ensure_head_or_fork`] instead.
 pub fn fork(
    store: &impl Store,
+    source_session_id: SessionId,
    state: SegmentStartState<'_>,
 ) -> Result<(SessionId, SegmentId), StoreError> {
    let session_id = crate::new_session_id();
    let fork_id = crate::new_segment_id();
-    let entry = LogEntry::SegmentStart {
-        ts: segment_log::now_millis(),
-        session_id,
-        system_prompt: state.system_prompt.map(String::from),
-        config: state.config.clone(),
-        history: to_logged(state.history),
-        forked_from: None,
-        compacted_from: None,
-    };
-    store.create_segment(session_id, fork_id, &[entry])?;
+    let entries = seed_entries(segment_log::now_millis(), session_id, state, None, None);
+    store.create_segment(session_id, fork_id, &entries)?;
+    store.copy_committed_uploaded_files(source_session_id, session_id)?;
    Ok((session_id, fork_id))
 }

@@ -464,11 +469,18 @@ pub fn fork_at(
 ) -> Result<SegmentId, StoreError> {
    let entries = store.read_all(source_session_id, source_id)?;
    let cut = if at_turn_index == 0 {
-        // Branch directly after the SegmentStart (or whatever opens the
-        // segment), before any turn completes.
+        // Branch from the seeded state before any new turn completes. A typed
+        // input checkpoint immediately following SegmentStart is part of that
+        // seed and must stay atomic with its annotated history.
        entries
            .iter()
-            .position(|e| !matches!(e, LogEntry::SegmentStart { .. }))
+            .position(|entry| {
+                !matches!(
+                    entry,
+                    LogEntry::AnnotatedSegmentStart { .. }
+                        | LogEntry::InputSegmentsCheckpoint { .. }
+                )
+            })
            .unwrap_or(entries.len())
    } else {
        entries
@@ -480,19 +492,27 @@ pub fn fork_at(
    let state = segment_log::collect_state(&entries[..cut]);

    let fork_id = crate::new_segment_id();
-    let entry = LogEntry::SegmentStart {
-        ts: segment_log::now_millis(),
+    let ts = segment_log::now_millis();
+    let entry = LogEntry::AnnotatedSegmentStart {
+        ts,
        session_id: source_session_id,
        system_prompt: state.system_prompt,
        config: state.config,
-        history: to_logged(&state.history),
+        history: state.annotated_history,
        forked_from: Some(SegmentOrigin {
            segment_id: source_id,
            at_turn_index,
        }),
        compacted_from: None,
    };
-    store.create_segment(source_session_id, fork_id, &[entry])?;
+    let mut fork_entries = vec![entry];
+    if !state.user_segments.is_empty() {
+        fork_entries.push(LogEntry::InputSegmentsCheckpoint {
+            ts,
+            user_segments: state.user_segments,
+        });
+    }
+    store.create_segment(source_session_id, fork_id, &fork_entries)?;
    Ok(fork_id)
 }

@@ -14,8 +14,8 @@ use agen::{EngineResult, UsageRecord};
 use protocol::{InvokeKind, Segment};
 use serde::{Deserialize, Serialize};

+use crate::history::{LoggedHistoryEntry, LoggedSystemHistoryEntry};
 use crate::logged_item::LoggedItem;
-use crate::system_item::SystemItem;

 /// A single segment log entry, serialized as one JSONL line.
 ///
@@ -49,27 +49,28 @@ impl SessionExtension {
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(tag = "kind", rename_all = "snake_case")]
 pub enum LogEntry {
-    /// Segment start. Always the first entry in a segment log.
-    /// For forked segments, `history` contains the seed state from the parent.
-    SegmentStart {
+    /// Canonical segment seed. Retained entries keep their stable logical
+    /// identity and origin across fork/compaction/restore.
+    AnnotatedSegmentStart {
        ts: u64,
-        /// Session this segment belongs to. Compaction / fork inherits
-        /// the source segment's session_id; only fresh "new conversation"
-        /// segments mint a new session_id.
        session_id: crate::SessionId,
        system_prompt: Option<String>,
        config: RequestConfig,
-        history: Vec<LoggedItem>,
-        /// Origin: forked from a sibling segment at a specific turn boundary.
-        /// The referenced segment is guaranteed to share `session_id`.
+        history: Vec<LoggedHistoryEntry>,
        #[serde(default, skip_serializing_if = "Option::is_none")]
        forked_from: Option<SegmentOrigin>,
-        /// Origin: compacted from a sibling segment at a specific turn boundary.
-        /// The referenced segment is guaranteed to share `session_id`.
        #[serde(default, skip_serializing_if = "Option::is_none")]
        compacted_from: Option<SegmentOrigin>,
    },

+    /// Typed user-segment projection accompanying a compacted or forked
+    /// SegmentStart history snapshot. This keeps attachment identity and
+    /// metadata aligned with retained user entries without embedding bodies.
+    InputSegmentsCheckpoint {
+        ts: u64,
+        user_segments: Vec<Vec<Segment>>,
+    },
+
    /// IDLE → active marker. Records the start of a new self-driving
    /// cycle (Invoke range). The range extends implicitly until the
    /// next `Invoke` entry; this entry carries the trigger only — the
@@ -90,46 +91,43 @@ pub enum LogEntry {
    /// restore conservatively instead of re-running a dangling tool call.
    Invoke { ts: u64, trigger: InvokeKind },

-    /// User input accepted at submit time. Carries the original typed
-    /// `Vec<Segment>` so clients can re-render typed atoms (paste chips,
-    /// file refs) on segment restore.
-    /// Replay flattens these into a `Item::user_message` for the worker
-    /// history; the worker layer never sees segments directly.
-    UserInput {
+    /// Canonical user submission with its exact model-visible entries. Typed
+    /// Flow instructions and caller-attributed input remain separate entries.
+    AnnotatedUserInput {
        ts: u64,
        segments: Vec<Segment>,
-        /// Typed durable state committed atomically with this input record.
-        /// Runtime-owned Flow invocation uses this to avoid a Backend-instance
-        /// commit that can get ahead of Worker history.
        #[serde(default, skip_serializing_if = "Vec::is_empty")]
        extensions: Vec<SessionExtension>,
+        history: Vec<LoggedHistoryEntry>,
    },

-    /// One assistant-side item appended to history — assistant message,
-    /// reasoning, or tool call. Singular: one entry per history item so
-    /// the wire-side `Event::*` lane and on-disk LogEntry stay 1:1.
-    AssistantItem { ts: u64, item: LoggedItem },
+    /// Canonical model output and metadata committed as one journal record.
+    AnnotatedAssistantItem { ts: u64, entry: LoggedHistoryEntry },

-    /// One tool-execution result appended to history.
-    ToolResult { ts: u64, item: LoggedItem },
+    /// Canonical tool output and metadata committed as one journal record.
+    AnnotatedToolResult { ts: u64, entry: LoggedHistoryEntry },

-    /// One typed agent-injected system item: notification, child-Worker
-    /// lifecycle event, `@<path>` / `/<slug>` resolution payload. Each
-    /// `SystemItem` carries kind metadata that the LLM
-    /// itself never sees (the LLM gets `Item::system_message` with the
-    /// item's denormalised `body`), but live clients and replay paths
-    /// dispatch on `kind` for typed rendering.
-    SystemItem { ts: u64, item: SystemItem },
+    /// Canonical typed system event and model-visible metadata committed
+    /// together.
+    AnnotatedSystemItem {
+        ts: u64,
+        entry: LoggedSystemHistoryEntry,
+    },

    /// Turn boundary. Records the turn count after increment.
    TurnEnd { ts: u64, turn_count: usize },

    /// `run()` / `resume()` が `EngineResult` で正常終了した。
-    /// Audit-only metadata: replay は `interrupted` のみ反映する。
+    /// Replay restores both interruption state and any resumable logical-run
+    /// turn budget.
    RunCompleted {
        ts: u64,
        interrupted: bool,
        result: EngineResult,
+        /// AgentTurns consumed by a paused/yielded logical run. Terminal
+        /// outcomes persist `None`.
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        active_run_turn_count: Option<usize>,
    },

    /// `run()` / `resume()` が `EngineError` で終了した。
@@ -141,6 +139,15 @@ pub enum LogEntry {
        message: String,
    },

+    /// Restores an active logical-run budget at a segment boundary, notably
+    /// after compaction replaced the segment that held the original Invoke and
+    /// RunCompleted entries.
+    ActiveRunCheckpoint {
+        ts: u64,
+        active_turn_count: usize,
+        total_turn_count: usize,
+    },
+
    /// A paused interrupted turn was explicitly abandoned without calling
    /// `run()` or `resume()` again. Replay clears the interrupted marker so
    /// the restored Worker is idle and future user input starts a normal new turn.
@@ -208,7 +215,13 @@ pub struct RestoredState {
    pub system_prompt: Option<String>,
    pub config: RequestConfig,
    pub history: Vec<Item>,
+    /// Canonical persisted history with stable identity and provenance. This is
+    /// the authority for rewrites, forks, and annotated restore; `history` is
+    /// retained as the model-facing item projection.
+    pub annotated_history: Vec<LoggedHistoryEntry>,
    pub turn_count: usize,
+    /// AgentTurns consumed by the active paused/yielded logical run.
+    pub active_run_turn_count: Option<usize>,
    pub last_run_interrupted: bool,
    /// Number of entries replayed. `0` means the segment log was empty.
    /// Writers track their own append count via the same counter so
@@ -222,7 +235,7 @@ pub struct RestoredState {
    /// session-store は domain を不透明扱いし、各ドメインが自前で fold する。
    pub extensions: Vec<(String, serde_json::Value)>,
    /// User submissions in original typed form, in submit order.
-    /// One entry per `LogEntry::UserInput`; the K-th entry corresponds to
+    /// One entry per `LogEntry::AnnotatedUserInput`; the K-th entry corresponds to
    /// the K-th `Item::user_message` derived during replay (modulo
    /// pre-compaction history seeded via `SegmentStart.history`, whose
    /// original segments are not preserved). Used by clients to re-render
@@ -237,7 +250,9 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
        system_prompt: None,
        config: RequestConfig::default(),
        history: Vec::new(),
+        annotated_history: Vec::new(),
        turn_count: 0,
+        active_run_turn_count: None,
        last_run_interrupted: false,
        entries_count: 0,
        usage_history: Vec::new(),
@@ -249,7 +264,7 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
        state.entries_count += 1;

        match entry {
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                session_id,
                system_prompt,
                config,
@@ -259,20 +274,32 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
                state.session_id = Some(*session_id);
                state.system_prompt = system_prompt.clone();
                state.config = config.clone();
-                state.history = history.iter().cloned().map(Item::from).collect();
+                state.annotated_history = history.clone();
+                state.history = history
+                    .iter()
+                    .cloned()
+                    .map(|entry| Item::from(entry.item))
+                    .collect();
+            }
+            LogEntry::InputSegmentsCheckpoint { user_segments, .. } => {
+                state.user_segments = user_segments.clone();
            }
            LogEntry::Invoke { .. } => {
                // A terminal run record below clears or refines this. If the
                // log ends first, restore must treat the turn as interrupted.
                state.last_run_interrupted = true;
+                state.active_run_turn_count = Some(0);
            }
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                segments,
                extensions,
+                history,
                ..
            } => {
-                let text = Segment::flatten_to_text(segments);
-                state.history.push(Item::user_message(text));
+                state.annotated_history.extend(history.iter().cloned());
+                state
+                    .history
+                    .extend(history.iter().cloned().map(|entry| Item::from(entry.item)));
                state.user_segments.push(segments.clone());
                state.extensions.extend(
                    extensions
@@ -280,26 +307,57 @@ pub fn collect_state(entries: &[LogEntry]) -> RestoredState {
                        .map(|extension| (extension.domain.clone(), extension.payload.clone())),
                );
            }
-            LogEntry::AssistantItem { item, .. } => {
-                state.history.push(Item::from(item.clone()));
+            LogEntry::AnnotatedAssistantItem { entry, .. }
+            | LogEntry::AnnotatedToolResult { entry, .. } => {
+                state.annotated_history.push(entry.clone());
+                state.history.push(Item::from(entry.item.clone()));
            }
-            LogEntry::ToolResult { item, .. } => {
-                state.history.push(Item::from(item.clone()));
-            }
-            LogEntry::SystemItem { item, .. } => {
-                state.history.push(item.to_history_item());
+            LogEntry::AnnotatedSystemItem { entry, .. } => {
+                state.annotated_history.push(LoggedHistoryEntry {
+                    item: LoggedItem::from(entry.item.to_history_item()),
+                    metadata: entry.metadata.clone(),
+                });
+                state.history.push(entry.item.to_history_item());
            }
            LogEntry::TurnEnd { turn_count, .. } => {
+                if let Some(active_turn_count) = &mut state.active_run_turn_count {
+                    *active_turn_count += turn_count.saturating_sub(state.turn_count);
+                }
                state.turn_count = *turn_count;
            }
-            LogEntry::RunCompleted { interrupted, .. } => {
+            LogEntry::RunCompleted {
+                interrupted,
+                result,
+                active_run_turn_count,
+                ..
+            } => {
                state.last_run_interrupted = *interrupted;
+                if *interrupted && matches!(result, EngineResult::Paused | EngineResult::Yielded) {
+                    // Legacy entries omit the explicit field; retain the
+                    // Invoke/TurnEnd-derived count in that case.
+                    if let Some(turn_count) = active_run_turn_count {
+                        state.active_run_turn_count = Some(*turn_count);
+                    }
+                } else {
+                    state.active_run_turn_count = None;
+                }
            }
            LogEntry::RunErrored { interrupted, .. } => {
                state.last_run_interrupted = *interrupted;
+                state.active_run_turn_count = None;
+            }
+            LogEntry::ActiveRunCheckpoint {
+                active_turn_count,
+                total_turn_count,
+                ..
+            } => {
+                state.active_run_turn_count = Some(*active_turn_count);
+                state.turn_count = *total_turn_count;
+                state.last_run_interrupted = true;
            }
            LogEntry::PausedTurnAbandoned { .. } => {
                state.last_run_interrupted = false;
+                state.active_run_turn_count = None;
            }
            LogEntry::ConfigChanged { config, .. } => {
                state.config = config.clone();
@@ -342,6 +400,20 @@ pub fn now_millis() -> u64 {
 #[cfg(test)]
 mod tests {
    use super::*;
+    use crate::{
+        LoggedSessionHistoryEntryId, LoggedSessionHistoryMetadata, LoggedSessionHistoryOrigin,
+    };
+
+    fn annotated(item: Item) -> LoggedHistoryEntry {
+        LoggedHistoryEntry {
+            item: LoggedItem::from(item),
+            metadata: LoggedSessionHistoryMetadata {
+                entry_id: LoggedSessionHistoryEntryId::new(),
+                origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+                derivation: None,
+            },
+        }
+    }

    #[test]
    fn replay_empty() {
@@ -353,12 +425,12 @@ mod tests {

    #[test]
    fn replay_segment_start_sets_initial_state() {
-        let state = collect_state(&[LogEntry::SegmentStart {
+        let state = collect_state(&[LogEntry::AnnotatedSegmentStart {
            ts: 1000,
            session_id: uuid::Uuid::nil(),
            system_prompt: Some("You are helpful.".into()),
            config: RequestConfig::default().with_max_tokens(1024),
-            history: vec![Item::user_message("seed").into()],
+            history: vec![annotated(Item::user_message("seed"))],
            forked_from: None,
            compacted_from: None,
        }]);
@@ -371,7 +443,7 @@ mod tests {
    #[test]
    fn replay_full_turn() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -380,14 +452,15 @@ mod tests {
                forked_from: None,
                compacted_from: None,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 2000,
                extensions: vec![],
                segments: vec![Segment::text("Hello")],
+                history: vec![annotated(Item::user_message("Hello"))],
            },
-            LogEntry::AssistantItem {
+            LogEntry::AnnotatedAssistantItem {
                ts: 3000,
-                item: Item::assistant_message("Hi!").into(),
+                entry: annotated(Item::assistant_message("Hi!")),
            },
            LogEntry::TurnEnd {
                ts: 3100,
@@ -397,6 +470,7 @@ mod tests {
                ts: 3200,
                interrupted: false,
                result: EngineResult::Finished,
+                active_run_turn_count: None,
            },
        ]);
        assert_eq!(state.history.len(), 2);
@@ -407,7 +481,7 @@ mod tests {
    #[test]
    fn replay_incomplete_invoke_is_interrupted() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -420,14 +494,15 @@ mod tests {
                ts: 2000,
                trigger: InvokeKind::UserSend,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 2001,
                extensions: vec![],
                segments: vec![Segment::text("run a tool")],
+                history: vec![annotated(Item::user_message("run a tool"))],
            },
-            LogEntry::AssistantItem {
+            LogEntry::AnnotatedAssistantItem {
                ts: 3000,
-                item: Item::tool_call("call_1", "side_effect", "{}").into(),
+                entry: annotated(Item::tool_call("call_1", "side_effect", "{}")),
            },
        ]);

@@ -437,7 +512,7 @@ mod tests {
    #[test]
    fn replay_with_tool_calls() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -446,22 +521,27 @@ mod tests {
                forked_from: None,
                compacted_from: None,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 2000,
                extensions: vec![],
                segments: vec![Segment::text("Check weather")],
+                history: vec![annotated(Item::user_message("Check weather"))],
            },
-            LogEntry::AssistantItem {
+            LogEntry::AnnotatedAssistantItem {
                ts: 3000,
-                item: Item::tool_call("call_1", "get_weather", r#"{"city":"Tokyo"}"#).into(),
+                entry: annotated(Item::tool_call(
+                    "call_1",
+                    "get_weather",
+                    r#"{"city":"Tokyo"}"#,
+                )),
            },
-            LogEntry::ToolResult {
+            LogEntry::AnnotatedToolResult {
                ts: 3500,
-                item: Item::tool_result("call_1", "Sunny, 25C").into(),
+                entry: annotated(Item::tool_result("call_1", "Sunny, 25C")),
            },
-            LogEntry::AssistantItem {
+            LogEntry::AnnotatedAssistantItem {
                ts: 4000,
-                item: Item::assistant_message("It's sunny in Tokyo!").into(),
+                entry: annotated(Item::assistant_message("It's sunny in Tokyo!")),
            },
            LogEntry::TurnEnd {
                ts: 4100,
@@ -475,9 +555,9 @@ mod tests {

    #[test]
    fn replay_restores_durable_tool_image_detail() {
-        let entry = LogEntry::ToolResult {
+        let entry = LogEntry::AnnotatedToolResult {
            ts: 3500,
-            item: Item::tool_result_item_with_attachments(
+            entry: annotated(Item::tool_result_item_with_attachments(
                "call_image",
                "attached",
                None,
@@ -485,8 +565,7 @@ mod tests {
                vec![agen::tool::Attachment::Image(
                    agen::tool::ImageAttachment::new("image/png", b"durable-image".to_vec()),
                )],
-            )
-            .into(),
+            )),
        };
        let persisted = serde_json::to_string(&entry).unwrap();
        let restored_entry: LogEntry = serde_json::from_str(&persisted).unwrap();
@@ -506,7 +585,7 @@ mod tests {
    #[test]
    fn replay_config_changed() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -526,7 +605,7 @@ mod tests {
    #[test]
    fn replay_llm_usage_appends_to_usage_history() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -535,10 +614,11 @@ mod tests {
                forked_from: None,
                compacted_from: None,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 2000,
                extensions: vec![],
                segments: vec![Segment::text("hi")],
+                history: vec![annotated(Item::user_message("hi"))],
            },
            LogEntry::LlmUsage {
                ts: 2100,
@@ -548,9 +628,9 @@ mod tests {
                cache_write_tokens: 0,
                output_tokens: 10,
            },
-            LogEntry::AssistantItem {
+            LogEntry::AnnotatedAssistantItem {
                ts: 2200,
-                item: Item::assistant_message("yo").into(),
+                entry: annotated(Item::assistant_message("yo")),
            },
            LogEntry::LlmUsage {
                ts: 3100,
@@ -574,7 +654,7 @@ mod tests {
    #[test]
    fn replay_without_llm_usage_keeps_usage_history_empty() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -583,10 +663,11 @@ mod tests {
                forked_from: None,
                compacted_from: None,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 2000,
                extensions: vec![],
                segments: vec![Segment::text("hi")],
+                history: vec![annotated(Item::user_message("hi"))],
            },
        ]);
        assert!(state.usage_history.is_empty());
@@ -647,7 +728,7 @@ mod tests {
    #[test]
    fn replay_invoke_marker_only_mutates_interrupted_state() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 0,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -660,10 +741,11 @@ mod tests {
                ts: 100,
                trigger: InvokeKind::UserSend,
            },
-            LogEntry::UserInput {
+            LogEntry::AnnotatedUserInput {
                ts: 101,
                extensions: vec![],
                segments: vec![Segment::text("hi")],
+                history: vec![annotated(Item::user_message("hi"))],
            },
            LogEntry::TurnEnd {
                ts: 200,
@@ -682,7 +764,7 @@ mod tests {
    #[test]
    fn replay_paused_turn_abandoned_clears_interrupted_marker() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 0,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -695,10 +777,93 @@ mod tests {
                ts: 100,
                interrupted: true,
                result: EngineResult::Paused,
+                active_run_turn_count: Some(1),
            },
            LogEntry::PausedTurnAbandoned { ts: 200 },
        ]);
        assert!(!state.last_run_interrupted);
+        assert_eq!(state.active_run_turn_count, None);
+    }
+
+    #[test]
+    fn replay_restores_active_run_budget_across_compaction_checkpoint() {
+        let state = collect_state(&[
+            LogEntry::AnnotatedSegmentStart {
+                ts: 0,
+                session_id: uuid::Uuid::nil(),
+                system_prompt: None,
+                config: RequestConfig::default(),
+                history: vec![],
+                forked_from: None,
+                compacted_from: None,
+            },
+            LogEntry::ActiveRunCheckpoint {
+                ts: 100,
+                active_turn_count: 3,
+                total_turn_count: 9,
+            },
+        ]);
+
+        assert_eq!(state.turn_count, 9);
+        assert_eq!(state.active_run_turn_count, Some(3));
+        assert!(state.last_run_interrupted);
+    }
+
+    #[test]
+    fn legacy_interrupted_run_derives_budget_from_invoke_and_turn_end() {
+        let entry: LogEntry = serde_json::from_value(serde_json::json!({
+            "kind": "run_completed",
+            "ts": 300,
+            "interrupted": true,
+            "result": "paused"
+        }))
+        .expect("legacy run-completed entry");
+        let state = collect_state(&[
+            LogEntry::AnnotatedSegmentStart {
+                ts: 0,
+                session_id: uuid::Uuid::nil(),
+                system_prompt: None,
+                config: RequestConfig::default(),
+                history: vec![],
+                forked_from: None,
+                compacted_from: None,
+            },
+            LogEntry::Invoke {
+                ts: 100,
+                trigger: InvokeKind::UserSend,
+            },
+            LogEntry::TurnEnd {
+                ts: 200,
+                turn_count: 2,
+            },
+            entry,
+        ]);
+
+        assert_eq!(state.active_run_turn_count, Some(2));
+        assert!(state.last_run_interrupted);
+    }
+
+    #[test]
+    fn non_resumable_interruption_clears_the_active_run_budget() {
+        let state = collect_state(&[
+            LogEntry::Invoke {
+                ts: 100,
+                trigger: InvokeKind::UserSend,
+            },
+            LogEntry::TurnEnd {
+                ts: 200,
+                turn_count: 2,
+            },
+            LogEntry::RunCompleted {
+                ts: 300,
+                interrupted: true,
+                result: EngineResult::LimitReached,
+                active_run_turn_count: None,
+            },
+        ]);
+
+        assert!(state.last_run_interrupted);
+        assert_eq!(state.active_run_turn_count, None);
    }

    #[test]
@@ -717,7 +882,7 @@ mod tests {
    #[test]
    fn replay_extension_collects_domain_payload_pairs() {
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1000,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -776,9 +941,12 @@ mod tests {
    #[test]
    fn user_input_extensions_restore_with_the_same_committed_input() {
        let segments = vec![Segment::text("Flow instructions"), Segment::text("Ticket")];
-        let entry = LogEntry::UserInput {
+        let entry = LogEntry::AnnotatedUserInput {
            ts: 9999,
            segments: segments.clone(),
+            history: vec![annotated(Item::user_message(Segment::flatten_to_text(
+                &segments,
+            )))],
            extensions: vec![SessionExtension::new(
                "flow.runtime.v1",
                serde_json::json!({ "state": "implement", "revision": 0 }),
@@ -793,7 +961,7 @@ mod tests {
        assert_eq!(state.extensions[0].1["state"], "implement");
    }

-    /// Mixed segments survive a JSON round-trip through `LogEntry::UserInput`,
+    /// Mixed segments survive a JSON round-trip through `LogEntry::AnnotatedUserInput`,
    /// and `collect_state` derives `Item::user_message` from the flattened
    /// text while preserving the original segments separately. This covers
    /// the segments → flatten → Item replay path from the ticket.
@@ -813,16 +981,19 @@ mod tests {
                path: "src/main.rs".into(),
            },
        ];
-        let entry = LogEntry::UserInput {
+        let entry = LogEntry::AnnotatedUserInput {
            ts: 4242,
            extensions: vec![],
            segments: segments.clone(),
+            history: vec![annotated(Item::user_message(Segment::flatten_to_text(
+                &segments,
+            )))],
        };
        // JSON round-trip preserves the variant byte-for-byte.
        let json = serde_json::to_string(&entry).unwrap();
        let parsed: LogEntry = serde_json::from_str(&json).unwrap();
        let state = collect_state(&[
-            LogEntry::SegmentStart {
+            LogEntry::AnnotatedSegmentStart {
                ts: 1,
                session_id: uuid::Uuid::nil(),
                system_prompt: None,
@@ -13,7 +13,10 @@

 use crate::event_trace::TraceEntry;
 use crate::segment_log::LogEntry;
-use crate::{SegmentId, SessionId};
+use crate::{
+    PasteArtifactLimits, SegmentId, SessionId, UploadedFileLimits, UploadedFileUploadContext,
+};
+use protocol::{PasteArtifactRef, UploadedFileRef};

 /// Errors from the persistence store.
 #[derive(Debug, thiserror::Error)]
@@ -29,6 +32,42 @@ pub enum StoreError {

    #[error("log corrupted at line {line}: {message}")]
    Corrupt { line: usize, message: String },
+
+    #[error("paste artifact storage is unavailable")]
+    PasteArtifactUnsupported,
+
+    #[error("paste artifact not found: {0}")]
+    PasteArtifactNotFound(String),
+
+    #[error("paste artifact integrity check failed: {0}")]
+    PasteArtifactIntegrity(String),
+
+    #[error("paste artifact size limit exceeded: {0}")]
+    PasteArtifactLimit(String),
+
+    #[error("uploaded file is too large")]
+    ArtifactTooLarge,
+
+    #[error("session artifact aggregate quota exceeded")]
+    ArtifactQuotaExceeded,
+
+    #[error("uploaded file reference integrity check failed")]
+    ArtifactIntegrityMismatch,
+
+    #[error("uploaded file name is invalid")]
+    InvalidUploadedFileName,
+
+    #[error("uploaded file media type is invalid")]
+    InvalidUploadedFileMediaType,
+
+    #[error("uploaded file is already committed to session history")]
+    ArtifactAlreadyCommitted,
+
+    #[error("artifact id is invalid")]
+    InvalidArtifactId,
+
+    #[error("artifact timestamp is invalid")]
+    InvalidTimestamp,
 }

 /// Sync persistence backend for segment logs.
@@ -117,6 +156,97 @@ pub trait Store: Send + Sync {
        segment_id: SegmentId,
    ) -> Result<usize, StoreError>;

+    /// Store a large paste before its reference is committed to history.
+    fn write_paste_artifact(
+        &self,
+        _session_id: SessionId,
+        _source_entry_id: &str,
+        _content: &str,
+        _limits: PasteArtifactLimits,
+    ) -> Result<PasteArtifactRef, StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    /// Read and verify one artifact owned by `session_id`.
+    fn read_paste_artifact(
+        &self,
+        _session_id: SessionId,
+        _artifact_id: &str,
+    ) -> Result<(PasteArtifactRef, String), StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    /// Persist a client-local file before a submission references it.
+    fn write_uploaded_file(
+        &self,
+        _session_id: SessionId,
+        _file_name: &str,
+        _media_type: &str,
+        _content: &[u8],
+        _limits: UploadedFileLimits,
+    ) -> Result<UploadedFileRef, StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    fn write_uploaded_file_with_context(
+        &self,
+        session_id: SessionId,
+        file_name: &str,
+        media_type: &str,
+        content: &[u8],
+        _context: &UploadedFileUploadContext,
+        limits: UploadedFileLimits,
+    ) -> Result<UploadedFileRef, StoreError> {
+        self.write_uploaded_file(session_id, file_name, media_type, content, limits)
+    }
+
+    /// Read and integrity-check an uploaded file owned by `session_id`.
+    fn read_uploaded_file(
+        &self,
+        _session_id: SessionId,
+        _reference: &UploadedFileRef,
+    ) -> Result<Vec<u8>, StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    fn read_uploaded_file_by_id(
+        &self,
+        _session_id: SessionId,
+        _artifact_id: &str,
+    ) -> Result<(UploadedFileRef, Vec<u8>), StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    fn bind_uploaded_file(
+        &self,
+        _session_id: SessionId,
+        _reference: &UploadedFileRef,
+        _source_entry_id: &str,
+    ) -> Result<UploadedFileRef, StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    /// Delete an uncommitted uploaded file owned by `session_id`.
+    fn delete_uploaded_file(
+        &self,
+        _session_id: SessionId,
+        _artifact_id: &str,
+    ) -> Result<bool, StoreError> {
+        Err(StoreError::PasteArtifactUnsupported)
+    }
+
+    fn delete_uncommitted_uploaded_files(&self, _session_id: SessionId) -> Result<u64, StoreError> {
+        Ok(0)
+    }
+
+    fn copy_committed_uploaded_files(
+        &self,
+        _source_session_id: SessionId,
+        _target_session_id: SessionId,
+    ) -> Result<u64, StoreError> {
+        Ok(0)
+    }
+
    /// Append a trace entry to the debug event trace file.
    fn append_trace(
        &self,
@@ -8,7 +8,7 @@
 //! `kind` instead of parsing text prefixes like `[Notification] …` or
 //! `[File: …]`.
 //!
-//! Persisted as the payload of [`crate::LogEntry::SystemItem`] (one
+//! Persisted as the payload of [`crate::LogEntry::AnnotatedSystemItem`] (one
 //! entry per item), and broadcast live as the payload of
 //! `Event::SystemItem` on the wire.
 //!
@@ -0,0 +1,534 @@
+use std::{
+    fs,
+    path::Path,
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+use base64::{Engine as _, engine::general_purpose::STANDARD as BASE64};
+use fs4::fs_std::FileExt;
+use protocol::{UploadedFileAvailability, UploadedFileRef};
+use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
+use unicode_normalization::UnicodeNormalization;
+use unicode_properties::general_category::{GeneralCategory, UnicodeGeneralCategory};
+use unicode_security::{confusable_detection::skeleton, mixed_script::MixedScript};
+use uuid::Uuid;
+
+use crate::StoreError;
+
+type Result<T> = std::result::Result<T, StoreError>;
+
+pub const DEFAULT_MAX_UPLOADED_FILE_BYTES: u64 = 10 * 1024 * 1024;
+pub const DEFAULT_MAX_SESSION_ARTIFACT_BYTES: u64 = 32 * 1024 * 1024;
+pub const DEFAULT_MAX_FILES_PER_SUBMISSION: usize = 8;
+pub const DEFAULT_MAX_SESSION_UPLOADED_FILES: u64 = 256;
+const MAX_FILE_NAME_CHARS: usize = 255;
+const MAX_MEDIA_TYPE_BYTES: usize = 127;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct UploadedFileLimits {
+    pub max_file_bytes: u64,
+    pub max_session_bytes: u64,
+}
+
+impl Default for UploadedFileLimits {
+    fn default() -> Self {
+        Self {
+            max_file_bytes: DEFAULT_MAX_UPLOADED_FILE_BYTES,
+            max_session_bytes: DEFAULT_MAX_SESSION_ARTIFACT_BYTES,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct UploadedFileUploadContext {
+    pub upload_id: String,
+    pub principal_id: String,
+    pub workspace_id: String,
+    pub runtime_id: String,
+    pub worker_id: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct StoredUploadedFile {
+    file_name: String,
+    media_type: String,
+    created_at_ms: u64,
+    byte_len: u64,
+    sha256: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    source_entry_id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    upload_context: Option<UploadedFileUploadContext>,
+    content_base64: String,
+}
+
+pub(crate) fn validate_file_name(file_name: &str) -> Result<()> {
+    let normalized: String = file_name.nfkc().collect();
+    let has_unsafe_component = file_name
+        .split('.')
+        .filter(|part| !part.is_empty())
+        .any(|part| {
+            let confusable_skeleton: String = skeleton(part).collect();
+            let ascii_confusable = part.chars().any(|ch| !ch.is_ascii())
+                && confusable_skeleton.is_ascii()
+                && !confusable_skeleton.eq_ignore_ascii_case(part);
+            !part.is_single_script() || ascii_confusable
+        });
+
+    if file_name.is_empty()
+        || file_name.chars().count() > MAX_FILE_NAME_CHARS
+        || file_name == "."
+        || file_name == ".."
+        || normalized != file_name
+        || has_unsafe_component
+        || file_name.chars().any(|ch| {
+            ch.is_control()
+                || ch.general_category() == GeneralCategory::Format
+                || matches!(ch, '/' | '\\')
+        })
+    {
+        return Err(StoreError::InvalidUploadedFileName);
+    }
+    Ok(())
+}
+
+pub(crate) fn validate_media_type(media_type: &str) -> Result<()> {
+    let valid = !media_type.is_empty()
+        && media_type.len() <= MAX_MEDIA_TYPE_BYTES
+        && media_type.is_ascii()
+        && !media_type
+            .bytes()
+            .any(|byte| byte.is_ascii_control() || byte == b' ')
+        && media_type.split_once('/').is_some_and(|(kind, subtype)| {
+            !kind.is_empty()
+                && !subtype.is_empty()
+                && kind.bytes().chain(subtype.bytes()).all(|byte| {
+                    byte.is_ascii_alphanumeric()
+                        || matches!(
+                            byte,
+                            b'!' | b'#' | b'$' | b'&' | b'^' | b'_' | b'.' | b'+' | b'-'
+                        )
+                })
+        });
+    let allowed = media_type.starts_with("text/")
+        || matches!(
+            media_type,
+            "application/json"
+                | "application/pdf"
+                | "image/png"
+                | "image/jpeg"
+                | "image/gif"
+                | "image/webp"
+        );
+    if !valid || !allowed {
+        return Err(StoreError::InvalidUploadedFileMediaType);
+    }
+    Ok(())
+}
+
+fn normalized_file_name(file_name: &str) -> String {
+    file_name.nfkc().flat_map(char::to_lowercase).collect()
+}
+
+fn validate_content(media_type: &str, content: &[u8]) -> Result<()> {
+    if content.is_empty() {
+        return Err(StoreError::InvalidUploadedFileMediaType);
+    }
+    let matches_declared_type = if media_type.starts_with("text/") {
+        std::str::from_utf8(content).is_ok()
+    } else {
+        match media_type {
+            "application/json" => serde_json::from_slice::<serde_json::Value>(content).is_ok(),
+            "application/pdf" => content.starts_with(b"%PDF-"),
+            "image/png" => content.starts_with(b"\x89PNG\r\n\x1a\n"),
+            "image/jpeg" => content.starts_with(&[0xff, 0xd8, 0xff]),
+            "image/gif" => content.starts_with(b"GIF87a") || content.starts_with(b"GIF89a"),
+            "image/webp" => {
+                content.len() >= 12 && content.starts_with(b"RIFF") && &content[8..12] == b"WEBP"
+            }
+            _ => false,
+        }
+    };
+    if !matches_declared_type {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    Ok(())
+}
+
+fn record_path(dir: &Path, artifact_id: &str) -> Result<std::path::PathBuf> {
+    let id = Uuid::parse_str(artifact_id).map_err(|_| StoreError::InvalidArtifactId)?;
+    Ok(dir.join(format!("{id}.file.json")))
+}
+
+fn now_ms() -> Result<u64> {
+    let value = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_err(|_| StoreError::InvalidTimestamp)?
+        .as_millis();
+    u64::try_from(value).map_err(|_| StoreError::InvalidTimestamp)
+}
+
+fn digest(bytes: &[u8]) -> String {
+    Sha256::digest(bytes)
+        .iter()
+        .map(|byte| format!("{byte:02x}"))
+        .collect()
+}
+
+pub(crate) fn stored_uploaded_file_usage(dir: &Path) -> Result<(u64, u64)> {
+    if !dir.exists() {
+        return Ok((0, 0));
+    }
+    let mut bytes = 0_u64;
+    let mut count = 0_u64;
+    for entry in fs::read_dir(dir)? {
+        let entry = entry?;
+        let path = entry.path();
+        if !entry.file_type()?.is_file()
+            || !path
+                .file_name()
+                .and_then(|name| name.to_str())
+                .is_some_and(|name| name.ends_with(".file.json"))
+        {
+            continue;
+        }
+        let stored: StoredUploadedFile = serde_json::from_slice(&fs::read(&path)?)?;
+        bytes = bytes
+            .checked_add(stored.byte_len)
+            .ok_or(StoreError::ArtifactQuotaExceeded)?;
+        count = count
+            .checked_add(1)
+            .ok_or(StoreError::ArtifactQuotaExceeded)?;
+    }
+    Ok((bytes, count))
+}
+
+pub(crate) fn write_uploaded_file(
+    dir: &Path,
+    file_name: &str,
+    media_type: &str,
+    content: &[u8],
+    context: Option<&UploadedFileUploadContext>,
+    limits: UploadedFileLimits,
+) -> Result<UploadedFileRef> {
+    validate_file_name(file_name)?;
+    validate_media_type(media_type)?;
+    validate_content(media_type, content)?;
+    let byte_len = u64::try_from(content.len()).map_err(|_| StoreError::ArtifactTooLarge)?;
+    let sha256 = digest(content);
+    if byte_len > limits.max_file_bytes {
+        return Err(StoreError::ArtifactTooLarge);
+    }
+
+    fs::create_dir_all(dir)?;
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let (paste_bytes, _) = crate::paste_artifact::stored_paste_usage(dir)?;
+    let (file_bytes, file_count) = stored_uploaded_file_usage(dir)?;
+    let normalized_name = normalized_file_name(file_name);
+    for entry in fs::read_dir(dir)? {
+        let path = entry?.path();
+        if !path
+            .file_name()
+            .and_then(|name| name.to_str())
+            .is_some_and(|name| name.ends_with(".file.json"))
+        {
+            continue;
+        }
+        let stored: StoredUploadedFile = serde_json::from_slice(&fs::read(&path)?)?;
+        let same_context = context.is_some() && stored.upload_context.as_ref() == context;
+        let same_uncommitted_name = stored.source_entry_id.is_none()
+            && normalized_file_name(&stored.file_name) == normalized_name;
+        if same_context || same_uncommitted_name {
+            if stored.file_name == file_name
+                && stored.media_type == media_type
+                && stored.byte_len == byte_len
+                && stored.sha256 == sha256
+                && stored.upload_context.as_ref() == context
+            {
+                let artifact_id = path
+                    .file_name()
+                    .and_then(|name| name.to_str())
+                    .and_then(|name| name.strip_suffix(".file.json"))
+                    .ok_or(StoreError::InvalidArtifactId)?
+                    .to_string();
+                return Ok(UploadedFileRef {
+                    artifact_id,
+                    file_name: stored.file_name,
+                    media_type: stored.media_type,
+                    created_at_ms: stored.created_at_ms,
+                    availability: UploadedFileAvailability::Available,
+                    byte_len: stored.byte_len,
+                    sha256: stored.sha256,
+                    source_entry_id: None,
+                });
+            }
+            return Err(StoreError::InvalidUploadedFileName);
+        }
+    }
+    if file_count >= DEFAULT_MAX_SESSION_UPLOADED_FILES {
+        return Err(StoreError::ArtifactQuotaExceeded);
+    }
+    if paste_bytes
+        .checked_add(file_bytes)
+        .and_then(|total| total.checked_add(byte_len))
+        .is_none_or(|total| total > limits.max_session_bytes)
+    {
+        return Err(StoreError::ArtifactQuotaExceeded);
+    }
+
+    let artifact_id = Uuid::now_v7().to_string();
+    let created_at_ms = now_ms()?;
+    let stored = StoredUploadedFile {
+        file_name: file_name.to_owned(),
+        media_type: media_type.to_owned(),
+        created_at_ms,
+        byte_len,
+        sha256: sha256.clone(),
+        source_entry_id: None,
+        upload_context: context.cloned(),
+        content_base64: BASE64.encode(content),
+    };
+    let path = record_path(dir, &artifact_id)?;
+    let temp = dir.join(format!(".{artifact_id}.file.tmp"));
+    fs::write(&temp, serde_json::to_vec(&stored)?)?;
+    fs::rename(&temp, &path)?;
+
+    Ok(UploadedFileRef {
+        artifact_id,
+        file_name: file_name.to_owned(),
+        media_type: media_type.to_owned(),
+        created_at_ms,
+        availability: UploadedFileAvailability::Available,
+        byte_len,
+        sha256,
+        source_entry_id: None,
+    })
+}
+
+pub(crate) fn read_uploaded_file_by_id(
+    dir: &Path,
+    artifact_id: &str,
+) -> Result<(UploadedFileRef, Vec<u8>)> {
+    let stored: StoredUploadedFile =
+        serde_json::from_slice(&fs::read(record_path(dir, artifact_id)?)?)?;
+    let content = BASE64
+        .decode(&stored.content_base64)
+        .map_err(|_| StoreError::ArtifactIntegrityMismatch)?;
+    if u64::try_from(content.len()).ok() != Some(stored.byte_len)
+        || digest(&content) != stored.sha256
+    {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    let reference = UploadedFileRef {
+        artifact_id: artifact_id.to_owned(),
+        file_name: stored.file_name,
+        media_type: stored.media_type,
+        created_at_ms: stored.created_at_ms,
+        availability: UploadedFileAvailability::Available,
+        byte_len: stored.byte_len,
+        sha256: stored.sha256,
+        source_entry_id: stored.source_entry_id,
+    };
+    Ok((reference, content))
+}
+
+pub(crate) fn read_uploaded_file(dir: &Path, reference: &UploadedFileRef) -> Result<Vec<u8>> {
+    let (stored_reference, content) = read_uploaded_file_by_id(dir, &reference.artifact_id)?;
+    if stored_reference.file_name != reference.file_name
+        || stored_reference.media_type != reference.media_type
+        || stored_reference.created_at_ms != reference.created_at_ms
+        || stored_reference.byte_len != reference.byte_len
+        || stored_reference.sha256 != reference.sha256
+        || stored_reference.source_entry_id != reference.source_entry_id
+    {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    Ok(content)
+}
+
+pub(crate) fn clear_uploaded_file_binding(
+    dir: &Path,
+    artifact_id: &str,
+    expected_source_entry_id: &str,
+) -> Result<()> {
+    fs::create_dir_all(dir)?;
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let path = record_path(dir, artifact_id)?;
+    let mut stored: StoredUploadedFile = serde_json::from_slice(&fs::read(&path)?)?;
+    if stored.source_entry_id.as_deref() != Some(expected_source_entry_id) {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    stored.source_entry_id = None;
+    let temp = dir.join(format!(".{artifact_id}.file.unbind.tmp"));
+    fs::write(&temp, serde_json::to_vec(&stored)?)?;
+    fs::rename(temp, path)?;
+    Ok(())
+}
+
+pub(crate) fn bind_uploaded_file(
+    dir: &Path,
+    reference: &UploadedFileRef,
+    source_entry_id: &str,
+) -> Result<UploadedFileRef> {
+    if source_entry_id.is_empty() || reference.source_entry_id.is_some() {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let (stored_reference, _) = read_uploaded_file_by_id(dir, &reference.artifact_id)?;
+    if stored_reference.file_name != reference.file_name
+        || stored_reference.media_type != reference.media_type
+        || stored_reference.created_at_ms != reference.created_at_ms
+        || stored_reference.byte_len != reference.byte_len
+        || stored_reference.sha256 != reference.sha256
+    {
+        return Err(StoreError::ArtifactIntegrityMismatch);
+    }
+    let path = record_path(dir, &reference.artifact_id)?;
+    let mut stored: StoredUploadedFile = serde_json::from_slice(&fs::read(&path)?)?;
+    if stored.source_entry_id.is_some() {
+        return Err(StoreError::ArtifactAlreadyCommitted);
+    }
+    stored.source_entry_id = Some(source_entry_id.to_owned());
+    let temp = dir.join(format!(".{}.file.bind.tmp", reference.artifact_id));
+    fs::write(&temp, serde_json::to_vec(&stored)?)?;
+    fs::rename(&temp, path)?;
+    let mut bound = reference.clone();
+    bound.source_entry_id = Some(source_entry_id.to_owned());
+    Ok(bound)
+}
+
+pub(crate) fn list_uploaded_file_refs(dir: &Path) -> Result<Vec<UploadedFileRef>> {
+    if !dir.exists() {
+        return Ok(Vec::new());
+    }
+    let mut refs = Vec::new();
+    for entry in fs::read_dir(dir)? {
+        let path = entry?.path();
+        let Some(artifact_id) = path
+            .file_name()
+            .and_then(|name| name.to_str())
+            .and_then(|name| name.strip_suffix(".file.json"))
+        else {
+            continue;
+        };
+        refs.push(read_uploaded_file_by_id(dir, artifact_id)?.0);
+    }
+    Ok(refs)
+}
+
+pub(crate) fn copy_committed_uploaded_files(source_dir: &Path, target_dir: &Path) -> Result<u64> {
+    if !source_dir.exists() {
+        return Ok(0);
+    }
+    fs::create_dir_all(target_dir)?;
+    let target_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(target_dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&target_lock)?;
+    let mut copied = 0_u64;
+    for entry in fs::read_dir(source_dir)? {
+        let entry = entry?;
+        let path = entry.path();
+        let Some(name) = path.file_name().and_then(|name| name.to_str()) else {
+            continue;
+        };
+        if !name.ends_with(".file.json") {
+            continue;
+        }
+        let bytes = fs::read(&path)?;
+        let stored: StoredUploadedFile = serde_json::from_slice(&bytes)?;
+        if stored.source_entry_id.is_none() {
+            continue;
+        }
+        let target = target_dir.join(name);
+        if target.exists() {
+            let existing: StoredUploadedFile = serde_json::from_slice(&fs::read(&target)?)?;
+            if existing.sha256 != stored.sha256
+                || existing.file_name != stored.file_name
+                || existing.source_entry_id != stored.source_entry_id
+            {
+                return Err(StoreError::ArtifactIntegrityMismatch);
+            }
+            continue;
+        }
+        let temp = target_dir.join(format!(".{name}.copy.tmp"));
+        fs::write(&temp, &bytes)?;
+        fs::rename(temp, target)?;
+        copied = copied
+            .checked_add(1)
+            .ok_or(StoreError::ArtifactQuotaExceeded)?;
+    }
+    Ok(copied)
+}
+
+pub(crate) fn delete_uncommitted_uploaded_files(dir: &Path) -> Result<u64> {
+    fs::create_dir_all(dir)?;
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let mut removed = 0_u64;
+    for entry in fs::read_dir(dir)? {
+        let entry = entry?;
+        let path = entry.path();
+        if !path
+            .file_name()
+            .and_then(|name| name.to_str())
+            .is_some_and(|name| name.ends_with(".file.json"))
+        {
+            continue;
+        }
+        let stored: StoredUploadedFile = serde_json::from_slice(&fs::read(&path)?)?;
+        if stored.source_entry_id.is_none() {
+            fs::remove_file(path)?;
+            removed = removed
+                .checked_add(1)
+                .ok_or(StoreError::ArtifactQuotaExceeded)?;
+        }
+    }
+    Ok(removed)
+}
+
+pub(crate) fn delete_uploaded_file(dir: &Path, artifact_id: &str) -> Result<bool> {
+    fs::create_dir_all(dir)?;
+    let aggregate_lock = fs::OpenOptions::new()
+        .create(true)
+        .read(true)
+        .write(true)
+        .open(dir.join(".aggregate.lock"))?;
+    FileExt::lock_exclusive(&aggregate_lock)?;
+    let path = record_path(dir, artifact_id)?;
+    let stored = match fs::read(&path) {
+        Ok(bytes) => serde_json::from_slice::<StoredUploadedFile>(&bytes)?,
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => return Ok(false),
+        Err(error) => return Err(error.into()),
+    };
+    if stored.source_entry_id.is_some() {
+        return Err(StoreError::ArtifactAlreadyCommitted);
+    }
+    match fs::remove_file(path) {
+        Ok(()) => Ok(true),
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => Ok(false),
+        Err(error) => Err(error.into()),
+    }
+}
@@ -608,6 +608,24 @@ where
    ) -> Result<usize, crate::StoreError> {
        self.session_store.read_entry_count(session_id, segment_id)
    }
+    fn write_paste_artifact(
+        &self,
+        session_id: SessionId,
+        source_entry_id: &str,
+        content: &str,
+        limits: crate::PasteArtifactLimits,
+    ) -> Result<protocol::PasteArtifactRef, crate::StoreError> {
+        self.session_store
+            .write_paste_artifact(session_id, source_entry_id, content, limits)
+    }
+    fn read_paste_artifact(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<(protocol::PasteArtifactRef, String), crate::StoreError> {
+        self.session_store
+            .read_paste_artifact(session_id, artifact_id)
+    }
    fn append_trace(
        &self,
        session_id: SessionId,
@@ -10,9 +10,11 @@
 //! every later operation must use that same ID.

 use crate::event_trace::TraceEntry;
+use crate::paste_artifact::{read_from_dir, write_to_dir};
 use crate::segment_log::LogEntry;
 use crate::store::{Store, StoreError};
-use crate::{SegmentId, SessionId};
+use crate::{PasteArtifactLimits, SegmentId, SessionId};
+use protocol::PasteArtifactRef;
 use serde::{Deserialize, Serialize};
 use std::fs::{self, File, OpenOptions};
 use std::io::{Read, Seek, SeekFrom, Write};
@@ -20,9 +22,12 @@ use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex};
 use std::time::SystemTime;

-const SESSION_SCHEMA_VERSION: u32 = 1;
+const SESSION_SCHEMA_VERSION: u32 = 3;
+const PREVIOUS_SESSION_SCHEMA_VERSION: u32 = 2;
+const LEGACY_SESSION_SCHEMA_VERSION: u32 = 1;
 const SESSION_FILE: &str = "session.json";
 const SEGMENTS_DIR: &str = "segments";
+const PASTE_ARTIFACTS_DIR: &str = "artifacts/paste";

 #[derive(Clone)]
 pub struct WorkerSessionStore {
@@ -44,16 +49,29 @@ impl WorkerSessionStore {
        fs::create_dir_all(root.join(SEGMENTS_DIR))?;
        let session_id = match fs::read(root.join(SESSION_FILE)) {
            Ok(bytes) => {
-                let manifest: SessionManifest = serde_json::from_slice(&bytes)?;
-                if manifest.schema_version != SESSION_SCHEMA_VERSION {
+                let mut manifest: SessionManifest = serde_json::from_slice(&bytes)?;
+                match manifest.schema_version {
+                    SESSION_SCHEMA_VERSION => {
+                        validate_canonical_segment_logs(&root)?;
+                    }
+                    PREVIOUS_SESSION_SCHEMA_VERSION | LEGACY_SESSION_SCHEMA_VERSION => {
+                        migrate_segment_logs_to_v3(
+                            &root,
+                            manifest.session_id,
+                            manifest.schema_version,
+                        )?;
+                        manifest.schema_version = SESSION_SCHEMA_VERSION;
+                        atomic_write_json(&root.join(SESSION_FILE), &manifest)?;
+                    }
+                    version => {
                        return Err(StoreError::Corrupt {
                            line: 0,
                            message: format!(
-                            "unsupported Worker Session schema version {}, expected {}",
-                            manifest.schema_version, SESSION_SCHEMA_VERSION
+                                "unsupported Worker Session schema version {version}, expected {SESSION_SCHEMA_VERSION}"
                            ),
                        });
                    }
+                }
                Some(manifest.session_id)
            }
            Err(error) if error.kind() == std::io::ErrorKind::NotFound => None,
@@ -136,6 +154,41 @@ impl WorkerSessionStore {
            .join(format!("{segment_id}.trace.jsonl"))
    }

+    fn append_log_entry(&self, path: &Path, entry: &LogEntry) -> Result<(), StoreError> {
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("Worker Session append lock was poisoned"))?;
+        let mut file = OpenOptions::new()
+            .create(true)
+            .read(true)
+            .write(true)
+            .append(true)
+            .open(path)?;
+        let committed_len = truncate_uncommitted_tail(&mut file)?;
+        file.seek(SeekFrom::Start(0))?;
+        let mut existing = Vec::new();
+        file.read_to_end(&mut existing)?;
+        parse_jsonl::<LogEntry>(&existing)?;
+        let line = serde_json::to_string(entry)?;
+        let mut record = Vec::with_capacity(line.len() + 1);
+        record.extend_from_slice(line.as_bytes());
+        record.push(b'\n');
+        if let Err(write_error) = file.write_all(&record) {
+            return match file.set_len(committed_len) {
+                Ok(()) => Err(write_error.into()),
+                Err(rollback_error) => Err(std::io::Error::new(
+                    rollback_error.kind(),
+                    format!(
+                        "session append failed ({write_error}) and rollback failed: {rollback_error}"
+                    ),
+                )
+                .into()),
+            };
+        }
+        Ok(())
+    }
+
    fn append_line(&self, path: &Path, line: &str) -> Result<(), StoreError> {
        let _guard = self
            .append_lock
@@ -175,7 +228,7 @@ impl Store for WorkerSessionStore {
        entry: &LogEntry,
    ) -> Result<(), StoreError> {
        self.ensure_session(session_id, true)?;
-        self.append_line(&self.log_path(segment_id), &serde_json::to_string(entry)?)
+        self.append_log_entry(&self.log_path(segment_id), entry)
    }

    fn read_all(
@@ -267,6 +320,35 @@ impl Store for WorkerSessionStore {
            .count())
    }

+    fn write_paste_artifact(
+        &self,
+        session_id: SessionId,
+        source_entry_id: &str,
+        content: &str,
+        limits: PasteArtifactLimits,
+    ) -> Result<PasteArtifactRef, StoreError> {
+        self.ensure_session(session_id, true)?;
+        let _guard = self
+            .append_lock
+            .lock()
+            .map_err(|_| std::io::Error::other("Worker Session append lock was poisoned"))?;
+        write_to_dir(
+            &self.root.join(PASTE_ARTIFACTS_DIR),
+            source_entry_id,
+            content,
+            limits,
+        )
+    }
+
+    fn read_paste_artifact(
+        &self,
+        session_id: SessionId,
+        artifact_id: &str,
+    ) -> Result<(PasteArtifactRef, String), StoreError> {
+        self.ensure_session(session_id, false)?;
+        read_from_dir(&self.root.join(PASTE_ARTIFACTS_DIR), artifact_id)
+    }
+
    fn append_trace(
        &self,
        session_id: SessionId,
@@ -278,6 +360,138 @@ impl Store for WorkerSessionStore {
    }
 }

+fn segment_log_paths(root: &Path) -> Result<Vec<(SegmentId, PathBuf)>, StoreError> {
+    let segments = root.join(SEGMENTS_DIR);
+    if !segments.exists() {
+        return Ok(Vec::new());
+    }
+    let mut paths = Vec::new();
+    for entry in fs::read_dir(&segments)? {
+        let entry = entry?;
+        let path = entry.path();
+        let metadata = fs::symlink_metadata(&path)?;
+        let Some(name) = path.file_name().and_then(|name| name.to_str()) else {
+            return Err(StoreError::Corrupt {
+                line: 0,
+                message: format!("non-UTF-8 Worker Session segment path: {}", path.display()),
+            });
+        };
+        if name.ends_with(".trace.jsonl") || name.starts_with('.') {
+            continue;
+        }
+        if !name.ends_with(".jsonl") {
+            continue;
+        }
+        if !metadata.file_type().is_file() {
+            return Err(StoreError::Corrupt {
+                line: 0,
+                message: format!(
+                    "Worker Session segment is not a regular file: {}",
+                    path.display()
+                ),
+            });
+        }
+        let segment_id =
+            name.trim_end_matches(".jsonl")
+                .parse()
+                .map_err(|_| StoreError::Corrupt {
+                    line: 0,
+                    message: format!("invalid Worker Session segment name: {name}"),
+                })?;
+        paths.push((segment_id, path));
+    }
+    paths.sort_by_key(|(segment_id, _)| *segment_id);
+    Ok(paths)
+}
+
+fn migrate_segment_logs_to_v3(
+    root: &Path,
+    session_id: SessionId,
+    source_schema_version: u32,
+) -> Result<(), StoreError> {
+    struct MigrationPlan {
+        path: PathBuf,
+        source: Vec<u8>,
+        output: Vec<u8>,
+    }
+
+    // Phase 1 is strictly read-only. Every segment must parse and canonicalize
+    // successfully before the first authoritative byte is replaced.
+    let mut plans = Vec::new();
+    for (segment_id, path) in segment_log_paths(root)? {
+        let source = fs::read(&path)?;
+        let canonical = parse_legacy_jsonl(source_schema_version, session_id, segment_id, &source)
+            .map_err(|error| StoreError::Corrupt {
+                line: 0,
+                message: format!(
+                    "cannot migrate Worker Session log {}: {error}",
+                    path.display()
+                ),
+            })?;
+        let mut output = Vec::new();
+        for entry in canonical {
+            serde_json::to_writer(&mut output, &entry)?;
+            output.push(b'\n');
+        }
+        plans.push(MigrationPlan {
+            path,
+            source,
+            output,
+        });
+    }
+
+    // Fence the complete preflight snapshot before starting phase 2. Session
+    // open is the exclusive restore boundary; this additionally fails closed
+    // if an unexpected writer raced the preflight.
+    for plan in &plans {
+        if fs::read(&plan.path)? != plan.source {
+            return Err(StoreError::Corrupt {
+                line: 0,
+                message: format!(
+                    "Worker Session segment changed during migration: {}",
+                    plan.path.display()
+                ),
+            });
+        }
+    }
+
+    for plan in plans {
+        atomic_write_bytes(&plan.path, &plan.output)?;
+    }
+    Ok(())
+}
+
+fn validate_canonical_segment_logs(root: &Path) -> Result<(), StoreError> {
+    for (_, path) in segment_log_paths(root)? {
+        let _: Vec<LogEntry> = parse_jsonl(&fs::read(&path)?)?;
+    }
+    Ok(())
+}
+
+fn parse_legacy_jsonl(
+    schema_version: u32,
+    session_id: SessionId,
+    segment_id: SegmentId,
+    bytes: &[u8],
+) -> Result<Vec<LogEntry>, serde_json::Error> {
+    let text = std::str::from_utf8(bytes).map_err(|error| {
+        serde_json::Error::io(std::io::Error::new(std::io::ErrorKind::InvalidData, error))
+    })?;
+    text.lines()
+        .enumerate()
+        .filter(|(_, line)| !line.trim().is_empty())
+        .map(|(line_index, line)| {
+            crate::legacy_session_log::decode_entry(
+                schema_version,
+                line,
+                session_id,
+                segment_id,
+                line_index,
+            )
+        })
+        .collect()
+}
+
 fn atomic_write_json<T: Serialize>(path: &Path, value: &T) -> Result<(), StoreError> {
    let mut bytes = serde_json::to_vec_pretty(value)?;
    bytes.push(b'\n');
@@ -379,7 +593,21 @@ fn truncate_uncommitted_tail(file: &mut File) -> std::io::Result<u64> {
 #[cfg(test)]
 mod tests {
    use super::*;
-    use crate::{Store, new_segment_id, new_session_id};
+    use crate::{
+        LoggedHistoryEntry, LoggedItem, LoggedSessionHistoryEntryId, LoggedSessionHistoryMetadata,
+        LoggedSessionHistoryOrigin, Store, new_segment_id, new_session_id,
+    };
+
+    fn annotated(item: agen::Item) -> LoggedHistoryEntry {
+        LoggedHistoryEntry {
+            item: LoggedItem::from(item),
+            metadata: LoggedSessionHistoryMetadata {
+                entry_id: LoggedSessionHistoryEntryId::new(),
+                origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+                derivation: None,
+            },
+        }
+    }

    #[test]
    fn canonical_layout_and_single_session_invariant() {
@@ -405,6 +633,367 @@ mod tests {
        assert_eq!(store.list_sessions().unwrap(), vec![session_id]);
    }

+    #[test]
+    fn worker_session_store_keeps_paste_artifacts_inside_retention_root() {
+        let root = tempfile::tempdir().unwrap();
+        let store = WorkerSessionStore::new(root.path().join("session")).unwrap();
+        let session_id = new_session_id();
+        store
+            .create_segment(session_id, new_segment_id(), &[])
+            .unwrap();
+        let content = "large paste body\n終端\n";
+        let reference = store
+            .write_paste_artifact(
+                session_id,
+                "entry-1",
+                content,
+                PasteArtifactLimits::default(),
+            )
+            .unwrap();
+
+        assert!(
+            root.path()
+                .join(format!(
+                    "session/{PASTE_ARTIFACTS_DIR}/{}.json",
+                    reference.artifact_id
+                ))
+                .is_file()
+        );
+        assert_eq!(
+            store
+                .read_paste_artifact(session_id, &reference.artifact_id)
+                .unwrap()
+                .1,
+            content
+        );
+        assert!(matches!(
+            store.read_paste_artifact(new_session_id(), &reference.artifact_id),
+            Err(StoreError::Corrupt { .. })
+        ));
+    }
+
+    #[test]
+    fn schema_v1_logs_are_rewritten_and_promoted_to_v3() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let segment_id = new_segment_id();
+        WorkerSessionStore::new(root.path())
+            .unwrap()
+            .create_segment(session_id, segment_id, &[])
+            .unwrap();
+        let manifest_path = root.path().join(SESSION_FILE);
+        let mut manifest: SessionManifest =
+            serde_json::from_slice(&fs::read(&manifest_path).unwrap()).unwrap();
+        manifest.schema_version = LEGACY_SESSION_SCHEMA_VERSION;
+        atomic_write_json(&manifest_path, &manifest).unwrap();
+
+        let reopened = WorkerSessionStore::new(root.path()).unwrap();
+        assert_eq!(reopened.session_id().unwrap(), Some(session_id));
+        let migrated: SessionManifest =
+            serde_json::from_slice(&fs::read(&manifest_path).unwrap()).unwrap();
+        assert_eq!(migrated.schema_version, SESSION_SCHEMA_VERSION);
+    }
+
+    #[test]
+    fn schema_v1_migration_rejects_corrupt_log_before_v3_manifest_update() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let manifest = SessionManifest {
+            schema_version: LEGACY_SESSION_SCHEMA_VERSION,
+            session_id,
+        };
+        atomic_write_json(&root.path().join(SESSION_FILE), &manifest).unwrap();
+        fs::create_dir_all(root.path().join(SEGMENTS_DIR)).unwrap();
+        fs::write(
+            root.path().join(SEGMENTS_DIR).join("broken.jsonl"),
+            "{not-json}\n",
+        )
+        .unwrap();
+
+        let error = match WorkerSessionStore::new(root.path()) {
+            Ok(_) => panic!("corrupt legacy Session log must reject migration"),
+            Err(error) => error,
+        };
+        assert!(matches!(error, StoreError::Corrupt { .. }));
+        let persisted: SessionManifest =
+            serde_json::from_slice(&fs::read(root.path().join(SESSION_FILE)).unwrap()).unwrap();
+        assert_eq!(persisted.schema_version, LEGACY_SESSION_SCHEMA_VERSION);
+    }
+
+    #[test]
+    fn schema_v2_migration_rewrites_legacy_records_with_stable_unknown_provenance() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let segment_id = new_segment_id();
+        fs::create_dir_all(root.path().join(SEGMENTS_DIR)).unwrap();
+        atomic_write_json(
+            &root.path().join(SESSION_FILE),
+            &SessionManifest {
+                schema_version: PREVIOUS_SESSION_SCHEMA_VERSION,
+                session_id,
+            },
+        )
+        .unwrap();
+        let source = vec![
+            serde_json::json!({
+                "kind": "segment_start",
+                "ts": 1,
+                "session_id": session_id,
+                "system_prompt": null,
+                "config": agen::llm_client::RequestConfig::default(),
+                "history": [LoggedItem::from(agen::Item::assistant_message("prior"))],
+                "forked_from": null,
+                "compacted_from": null
+            }),
+            serde_json::json!({
+                "kind": "user_input",
+                "ts": 2,
+                "segments": [{ "kind": "text", "content": "hello" }],
+                "extensions": []
+            }),
+            serde_json::json!({
+                "kind": "assistant_item",
+                "ts": 3,
+                "item": LoggedItem::from(agen::Item::assistant_message("reply"))
+            }),
+        ];
+        let path = root
+            .path()
+            .join(SEGMENTS_DIR)
+            .join(format!("{segment_id}.jsonl"));
+        let mut bytes = Vec::new();
+        for entry in source {
+            serde_json::to_writer(&mut bytes, &entry).unwrap();
+            bytes.push(b'\n');
+        }
+        fs::write(&path, bytes).unwrap();
+
+        let store = WorkerSessionStore::new(root.path()).unwrap();
+        let first = store.read_all(session_id, segment_id).unwrap();
+        assert!(matches!(first[0], LogEntry::AnnotatedSegmentStart { .. }));
+        assert!(matches!(first[1], LogEntry::AnnotatedUserInput { .. }));
+        assert!(matches!(first[2], LogEntry::AnnotatedAssistantItem { .. }));
+        let first_bytes = fs::read(&path).unwrap();
+        drop(store);
+
+        let reopened = WorkerSessionStore::new(root.path()).unwrap();
+        assert_eq!(fs::read(&path).unwrap(), first_bytes);
+        let snapshot = crate::public_snapshot::project_current_session_snapshot(
+            &reopened.read_all(session_id, segment_id).unwrap(),
+        );
+        assert_eq!(snapshot.entries.len(), 3);
+        assert_eq!(
+            snapshot
+                .entries
+                .iter()
+                .map(|entry| entry.timestamp)
+                .collect::<Vec<_>>(),
+            vec![1, 2, 3]
+        );
+        assert!(snapshot.entries.iter().all(|entry| {
+            entry.provenance == protocol::SessionEntryProvenance::LegacyUnknown
+                && entry.entry_id.len() <= 64
+        }));
+    }
+
+    #[test]
+    fn schema_v2_preflight_keeps_earlier_segments_unchanged_when_later_is_corrupt() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let valid_segment = uuid::Uuid::from_u128(1);
+        let corrupt_segment = uuid::Uuid::from_u128(2);
+        fs::create_dir_all(root.path().join(SEGMENTS_DIR)).unwrap();
+        atomic_write_json(
+            &root.path().join(SESSION_FILE),
+            &SessionManifest {
+                schema_version: PREVIOUS_SESSION_SCHEMA_VERSION,
+                session_id,
+            },
+        )
+        .unwrap();
+        let manifest_before = fs::read(root.path().join(SESSION_FILE)).unwrap();
+
+        let valid_path = root
+            .path()
+            .join(SEGMENTS_DIR)
+            .join(format!("{valid_segment}.jsonl"));
+        let valid_entry = serde_json::json!({
+            "kind": "segment_start",
+            "ts": 1,
+            "session_id": session_id,
+            "system_prompt": null,
+            "config": agen::llm_client::RequestConfig::default(),
+            "history": [LoggedItem::from(agen::Item::assistant_message("prior"))],
+            "forked_from": null,
+            "compacted_from": null
+        });
+        let mut valid_bytes = serde_json::to_vec(&valid_entry).unwrap();
+        valid_bytes.push(b'\n');
+        fs::write(&valid_path, &valid_bytes).unwrap();
+        let corrupt_path = root
+            .path()
+            .join(SEGMENTS_DIR)
+            .join(format!("{corrupt_segment}.jsonl"));
+        fs::write(&corrupt_path, b"{not-json}\n").unwrap();
+        let corrupt_before = fs::read(&corrupt_path).unwrap();
+
+        let error = match WorkerSessionStore::new(root.path()) {
+            Ok(_) => panic!("later corrupt segment must fail migration preflight"),
+            Err(error) => error,
+        };
+        assert!(matches!(error, StoreError::Corrupt { .. }));
+        assert_eq!(fs::read(&valid_path).unwrap(), valid_bytes);
+        assert_eq!(fs::read(&corrupt_path).unwrap(), corrupt_before);
+        assert_eq!(
+            fs::read(root.path().join(SESSION_FILE)).unwrap(),
+            manifest_before
+        );
+    }
+
+    #[test]
+    fn current_jsonl_requires_annotations_across_append_rewrite_and_reopen() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let segment_id = new_segment_id();
+        let store = WorkerSessionStore::new(root.path()).unwrap();
+        store
+            .create_segment(
+                session_id,
+                segment_id,
+                &[LogEntry::AnnotatedSegmentStart {
+                    ts: 1,
+                    session_id,
+                    system_prompt: None,
+                    config: agen::llm_client::RequestConfig::default(),
+                    history: vec![annotated(agen::Item::user_message("seed"))],
+                    forked_from: None,
+                    compacted_from: None,
+                }],
+            )
+            .unwrap();
+        store
+            .append(
+                session_id,
+                segment_id,
+                &LogEntry::AnnotatedAssistantItem {
+                    ts: 2,
+                    entry: annotated(agen::Item::assistant_message("reply")),
+                },
+            )
+            .unwrap();
+
+        let before_rewrite = store.read_all(session_id, segment_id).unwrap();
+        store
+            .create_segment(session_id, segment_id, &before_rewrite)
+            .unwrap();
+        drop(store);
+
+        let reopened = WorkerSessionStore::new(root.path()).unwrap();
+        let restored = reopened.read_all(session_id, segment_id).unwrap();
+        assert_eq!(
+            serde_json::to_value(&restored).unwrap(),
+            serde_json::to_value(&before_rewrite).unwrap()
+        );
+        for entry in &restored {
+            match entry {
+                LogEntry::AnnotatedSegmentStart { history, .. } => assert!(history.iter().all(
+                    |entry| !entry.metadata.entry_id.0.is_empty()
+                        && matches!(
+                            entry.metadata.origin,
+                            LoggedSessionHistoryOrigin::LegacyUnknown
+                        )
+                )),
+                LogEntry::AnnotatedAssistantItem { entry, .. } => {
+                    assert!(!entry.metadata.entry_id.0.is_empty());
+                    assert!(matches!(
+                        entry.metadata.origin,
+                        LoggedSessionHistoryOrigin::LegacyUnknown
+                    ));
+                }
+                _ => {}
+            }
+        }
+
+        let log = fs::read_to_string(reopened.log_path(segment_id)).unwrap();
+        for line in log.lines() {
+            let value: serde_json::Value = serde_json::from_str(line).unwrap();
+            let kind = value["kind"].as_str().unwrap();
+            assert!(
+                !matches!(
+                    kind,
+                    "segment_start"
+                        | "user_input"
+                        | "assistant_item"
+                        | "tool_result"
+                        | "system_item"
+                ),
+                "current-schema JSONL contains legacy history record: {kind}"
+            );
+        }
+    }
+
+    #[test]
+    fn schema_v3_rejects_legacy_records_and_new_writes_are_canonical() {
+        let root = tempfile::tempdir().unwrap();
+        let session_id = new_session_id();
+        let segment_id = new_segment_id();
+        let store = WorkerSessionStore::new(root.path()).unwrap();
+        store
+            .create_segment(
+                session_id,
+                segment_id,
+                &[LogEntry::AnnotatedSegmentStart {
+                    ts: 1,
+                    session_id,
+                    system_prompt: None,
+                    config: agen::llm_client::RequestConfig::default(),
+                    history: vec![annotated(agen::Item::assistant_message("seed"))],
+                    forked_from: None,
+                    compacted_from: None,
+                }],
+            )
+            .unwrap();
+        store
+            .append(
+                session_id,
+                segment_id,
+                &LogEntry::AnnotatedUserInput {
+                    ts: 2,
+                    segments: vec![protocol::Segment::Text {
+                        content: "new".into(),
+                    }],
+                    history: vec![annotated(agen::Item::user_message("new"))],
+                    extensions: Vec::new(),
+                },
+            )
+            .unwrap();
+        let entries = store.read_all(session_id, segment_id).unwrap();
+        assert!(matches!(entries[0], LogEntry::AnnotatedSegmentStart { .. }));
+        assert!(matches!(entries[1], LogEntry::AnnotatedUserInput { .. }));
+        drop(store);
+
+        let path = root
+            .path()
+            .join(SEGMENTS_DIR)
+            .join(format!("{segment_id}.jsonl"));
+        let mut file = OpenOptions::new().append(true).open(path).unwrap();
+        serde_json::to_writer(
+            &mut file,
+            &serde_json::json!({
+                "kind": "system_item",
+                "ts": 3,
+                "item": { "kind": "legacy_ignored", "slug": "legacy" }
+            }),
+        )
+        .unwrap();
+        file.write_all(b"\n").unwrap();
+        let error = match WorkerSessionStore::new(root.path()) {
+            Ok(_) => panic!("schema v3 must reject a legacy history record"),
+            Err(error) => error,
+        };
+        assert!(matches!(error, StoreError::Corrupt { .. }));
+    }
+
    #[test]
    fn reopen_preserves_session_and_segment_ids() {
        let root = tempfile::tempdir().unwrap();
@@ -1,12 +1,25 @@
 use agen::EngineResult;
 use agen::llm_client::types::{Item, RequestConfig};
 use session_store::{
-    FsStore, LogEntry, Store, TraceEntry, collect_state, new_segment_id, new_session_id,
+    FsStore, LogEntry, LoggedHistoryEntry, LoggedItem, LoggedSessionHistoryEntryId,
+    LoggedSessionHistoryMetadata, LoggedSessionHistoryOrigin, Store, TraceEntry, collect_state,
+    new_segment_id, new_session_id,
 };
 use std::io::Write;

+fn annotated(item: Item) -> LoggedHistoryEntry {
+    LoggedHistoryEntry {
+        item: LoggedItem::from(item),
+        metadata: LoggedSessionHistoryMetadata {
+            entry_id: LoggedSessionHistoryEntryId::new(),
+            origin: LoggedSessionHistoryOrigin::LegacyUnknown,
+            derivation: None,
+        },
+    }
+}
+
 fn nil_session_start(ts: u64, session_id: uuid::Uuid) -> LogEntry {
-    LogEntry::SegmentStart {
+    LogEntry::AnnotatedSegmentStart {
        ts,
        session_id,
        system_prompt: None,
@@ -25,7 +38,7 @@ fn round_trip_write_and_read() {
    let segid = new_segment_id();

    let entries = vec![
-        LogEntry::SegmentStart {
+        LogEntry::AnnotatedSegmentStart {
            ts: 1000,
            session_id: sid,
            system_prompt: Some("You are helpful.".into()),
@@ -34,14 +47,15 @@ fn round_trip_write_and_read() {
            forked_from: None,
            compacted_from: None,
        },
-        LogEntry::UserInput {
+        LogEntry::AnnotatedUserInput {
            ts: 2000,
            extensions: vec![],
            segments: vec![protocol::Segment::text("Hello")],
+            history: vec![annotated(Item::user_message("Hello"))],
        },
-        LogEntry::AssistantItem {
+        LogEntry::AnnotatedAssistantItem {
            ts: 3000,
-            item: Item::assistant_message("Hi there!").into(),
+            entry: annotated(Item::assistant_message("Hi there!")),
        },
        LogEntry::TurnEnd {
            ts: 3100,
@@ -51,6 +65,7 @@ fn round_trip_write_and_read() {
            ts: 3200,
            interrupted: false,
            result: EngineResult::Finished,
+            active_run_turn_count: None,
        },
    ];

@@ -78,14 +93,14 @@ fn create_segment_writes_all_entries() {
    let sid = new_session_id();
    let segid = new_segment_id();

-    let entries = [LogEntry::SegmentStart {
+    let entries = [LogEntry::AnnotatedSegmentStart {
        ts: 1000,
        session_id: sid,
        system_prompt: None,
        config: RequestConfig::default(),
        history: vec![
-            Item::user_message("seed").into(),
-            Item::assistant_message("ok").into(),
+            annotated(Item::user_message("seed")),
+            annotated(Item::assistant_message("ok")),
        ],
        forked_from: None,
        compacted_from: None,
@@ -204,7 +219,7 @@ fn read_entry_count_matches_append_tally() {
    let segid = new_segment_id();

    let entries = [
-        LogEntry::SegmentStart {
+        LogEntry::AnnotatedSegmentStart {
            ts: 1000,
            session_id: sid,
            system_prompt: None,
@@ -213,10 +228,11 @@ fn read_entry_count_matches_append_tally() {
            forked_from: None,
            compacted_from: None,
        },
-        LogEntry::UserInput {
+        LogEntry::AnnotatedUserInput {
            ts: 2000,
            extensions: vec![],
            segments: vec![protocol::Segment::text("Hello")],
+            history: vec![annotated(Item::user_message("Hello"))],
        },
    ];

@@ -253,10 +269,11 @@ fn unterminated_utf8_tail_is_ignored_and_replaced_on_append() {
    assert_eq!(store.read_all(sid, segid).unwrap().len(), 1);
    assert_eq!(store.read_entry_count(sid, segid).unwrap(), 1);

-    let next = LogEntry::UserInput {
+    let next = LogEntry::AnnotatedUserInput {
        ts: 2,
        extensions: vec![],
        segments: vec![protocol::Segment::text("recovered")],
+        history: vec![annotated(Item::user_message("recovered"))],
    };
    store.append(sid, segid, &next).unwrap();

@@ -1,20 +1,37 @@
 mod common;

+use std::ops::{Deref, DerefMut};
 use std::sync::Arc;

-use agen::Engine;
 use agen::interceptor::{Interceptor, TurnEndAction};
 use agen::llm_client::event::{Event, ResponseStatus, StatusEvent};
 use agen::llm_client::types::{Item, RequestConfig};
 use agen::tool::{Tool, ToolDefinition, ToolError, ToolMeta, ToolOutput};
+use agen::{Engine, History};
 use async_trait::async_trait;
 use common::MockLlmClient;
+use protocol::{Segment, SessionSnapshotEntryData, UploadedFileAvailability, UploadedFileRef};
 use session_store::{FsStore, LogEntry, SegmentStartState, Store, collect_state};

 // =============================================================================
 // Helpers
 // =============================================================================

+fn annotated(items: &[Item]) -> Vec<session_store::LoggedHistoryEntry> {
+    items
+        .iter()
+        .cloned()
+        .map(|item| session_store::LoggedHistoryEntry {
+            item: session_store::LoggedItem::from(item),
+            metadata: session_store::LoggedSessionHistoryMetadata {
+                entry_id: session_store::LoggedSessionHistoryEntryId::new(),
+                origin: session_store::LoggedSessionHistoryOrigin::LegacyUnknown,
+                derivation: None,
+            },
+        })
+        .collect()
+}
+
 fn simple_text_events() -> Vec<Event> {
    vec![
        Event::text_block_start(0),
@@ -94,15 +111,47 @@ fn make_store() -> (tempfile::TempDir, FsStore) {
    (dir, store)
 }

+struct TestWorker {
+    engine: Engine<MockLlmClient>,
+    history: History,
+}
+
+impl TestWorker {
+    fn new(engine: Engine<MockLlmClient>) -> Self {
+        Self {
+            engine,
+            history: History::new(),
+        }
+    }
+
+    fn history(&self) -> Vec<Item> {
+        self.history.items_cloned()
+    }
+}
+
+impl Deref for TestWorker {
+    type Target = Engine<MockLlmClient>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.engine
+    }
+}
+
+impl DerefMut for TestWorker {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.engine
+    }
+}
+
 /// Run a worker turn and persist via session-store functions.
 /// Takes ownership of the worker (needed for lock/unlock) and returns it.
 async fn run_and_persist(
-    worker: Engine<MockLlmClient>,
+    mut worker: TestWorker,
    store: &FsStore,
    session_id: session_store::SessionId,
    segment_id: session_store::SegmentId,
    input: &str,
-) -> (Engine<MockLlmClient>, agen::EngineResult) {
+) -> (TestWorker, agen::EngineRunExit) {
    // Mirror Worker's run-entry contract: log the user input as segments
    // before the worker pushes its flattened user_message; save_delta
    // skips the resulting user_message item to avoid double-write.
@@ -111,44 +160,65 @@ async fn run_and_persist(
        session_id,
        segment_id,
        vec![protocol::Segment::text(input)],
+        annotated(&[Item::user_message(input)]),
    )
    .unwrap();

-    let history_before = worker.history().len();
+    let history_before = worker.history.len();

-    let mut locked = worker.lock();
-    let result = locked.run(input).await;
-    let worker = locked.unlock();
+    let mut locked = worker.engine.lock(&worker.history);
+    let result = locked.run(&mut worker.history, input).await;
+    worker.engine = locked.unlock();

-    let new_items = &worker.history()[history_before..];
-    session_store::save_delta(store, session_id, segment_id, new_items).unwrap();
+    let projected = worker.history();
+    let new_items = annotated(&projected[history_before..]);
+    session_store::save_delta(store, session_id, segment_id, &new_items).unwrap();
    session_store::save_turn_end(store, session_id, segment_id, worker.turn_count()).unwrap();

    match &result {
-        Ok(r) => {
+        agen::EngineRunExit::Finished
+        | agen::EngineRunExit::Paused
+        | agen::EngineRunExit::Yielded => {
+            let (legacy_result, interrupted) = match &result {
+                agen::EngineRunExit::Finished => (agen::EngineResult::Finished, false),
+                agen::EngineRunExit::Paused => (agen::EngineResult::Paused, true),
+                agen::EngineRunExit::Yielded => (agen::EngineResult::Yielded, true),
+                agen::EngineRunExit::Interrupted(_) => unreachable!(),
+            };
            session_store::save_run_completed(
                store,
                session_id,
                segment_id,
-                r.clone(),
-                worker.last_run_interrupted(),
+                legacy_result,
+                interrupted,
+                worker.active_run_turn_count(),
            )
            .unwrap();
        }
-        Err(e) => {
+        agen::EngineRunExit::Interrupted(agen::StopReason::LimitReached) => {
+            session_store::save_run_completed(
+                store,
+                session_id,
+                segment_id,
+                agen::EngineResult::LimitReached,
+                false,
+                worker.active_run_turn_count(),
+            )
+            .unwrap();
+        }
+        agen::EngineRunExit::Interrupted(reason) => {
            session_store::save_run_errored(
                store,
                session_id,
                segment_id,
-                e.to_string(),
-                worker.last_run_interrupted(),
+                format!("{reason:?}"),
+                true,
            )
            .unwrap();
        }
    }

-    let r = result.unwrap();
-    (worker, r)
+    (worker, result)
 }

 // =============================================================================
@@ -159,14 +229,15 @@ async fn run_and_persist(
 async fn session_run_logs_entries() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(simple_text_events());
-    let worker = Engine::new(client);
+    let worker = TestWorker::new(Engine::new(client));

    let (sid, segid) = session_store::create_segment(
        &store,
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -184,7 +255,10 @@ async fn session_run_logs_entries() {
    );

    // First entry is SegmentStart
-    assert!(matches!(&entries[0], LogEntry::SegmentStart { .. }));
+    assert!(matches!(
+        &entries[0],
+        LogEntry::AnnotatedSegmentStart { .. }
+    ));

    // Has a RunCompleted with Finished
    let has_finished = entries.iter().any(|e| {
@@ -203,7 +277,7 @@ async fn session_run_logs_entries() {
 async fn session_restore_round_trip() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(simple_text_events());
-    let mut worker = Engine::new(client);
+    let mut worker = TestWorker::new(Engine::new(client));
    worker.set_system_prompt("You are helpful.");

    let (sid, segid) = session_store::create_segment(
@@ -211,7 +285,8 @@ async fn session_restore_round_trip() {
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -242,7 +317,7 @@ async fn session_restore_round_trip() {
 async fn session_run_with_tool_call() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::with_responses(tool_call_events());
-    let mut worker = Engine::new(client);
+    let mut worker = TestWorker::new(Engine::new(client));
    worker.register_tool(weather_tool_definition());

    let (sid, segid) = session_store::create_segment(
@@ -250,7 +325,8 @@ async fn session_run_with_tool_call() {
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -261,12 +337,12 @@ async fn session_run_with_tool_call() {

    let has_tool_results = entries
        .iter()
-        .any(|e| matches!(e, LogEntry::ToolResult { .. }));
+        .any(|e| matches!(e, LogEntry::AnnotatedToolResult { .. }));
    assert!(has_tool_results, "should have ToolResult entry");

    let has_assistant = entries
        .iter()
-        .any(|e| matches!(e, LogEntry::AssistantItem { .. }));
+        .any(|e| matches!(e, LogEntry::AnnotatedAssistantItem { .. }));
    assert!(has_assistant, "should have AssistantItem entry");
 }

@@ -276,7 +352,7 @@ async fn session_resume_after_pause() {

    // First run: tool call with pause policy → Paused
    let client = MockLlmClient::with_responses(tool_call_events());
-    let mut worker = Engine::new(client);
+    let mut worker = TestWorker::new(Engine::new(client));
    worker.register_tool(weather_tool_definition());
    worker.set_interceptor(PausePolicy);

@@ -285,13 +361,14 @@ async fn session_resume_after_pause() {
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();

    let (_worker, result) = run_and_persist(worker, &store, sid, segid, "Weather?").await;
-    assert!(matches!(result, agen::EngineResult::Paused));
+    assert!(matches!(result, agen::EngineRunExit::Paused));

    // Check RunCompleted is Paused
    let entries = store.read_all(sid, segid).unwrap();
@@ -309,13 +386,14 @@ async fn session_resume_after_pause() {
    // Restore state and verify
    let state = session_store::restore(&store, sid, segid).unwrap();
    assert!(state.last_run_interrupted);
+    assert_eq!(state.active_run_turn_count, Some(2));
 }

 #[tokio::test]
 async fn session_fork_creates_new_session() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(simple_text_events());
-    let mut worker = Engine::new(client);
+    let mut worker = TestWorker::new(Engine::new(client));
    worker.set_system_prompt("System prompt");

    let (sid, segid) = session_store::create_segment(
@@ -323,7 +401,8 @@ async fn session_fork_creates_new_session() {
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -331,25 +410,38 @@ async fn session_fork_creates_new_session() {
    let (worker, _) = run_and_persist(worker, &store, sid, segid, "Hello").await;

    let original_history_len = worker.history().len();
+    let source_user_segments = session_store::restore(&store, sid, segid)
+        .unwrap()
+        .user_segments;
    let (fork_sid, fork_segid) = session_store::fork(
        &store,
+        sid,
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: source_user_segments.clone(),
        },
    )
    .unwrap();
    assert_ne!(fork_sid, sid, "`fork` mints a fresh Session");

-    // Fork should have a SegmentStart with the current history
+    // Fork should have an annotated seed and typed input checkpoint.
    let fork_entries = store.read_all(fork_sid, fork_segid).unwrap();
-    assert_eq!(fork_entries.len(), 1);
-    assert!(matches!(&fork_entries[0], LogEntry::SegmentStart { .. }));
+    assert_eq!(fork_entries.len(), 2);
+    assert!(matches!(
+        &fork_entries[0],
+        LogEntry::AnnotatedSegmentStart { .. }
+    ));
+    assert!(matches!(
+        &fork_entries[1],
+        LogEntry::InputSegmentsCheckpoint { .. }
+    ));

    let fork_state = collect_state(&fork_entries);
    assert_eq!(fork_state.session_id, Some(fork_sid));
    assert_eq!(fork_state.history.len(), original_history_len);
+    assert_eq!(fork_state.user_segments, source_user_segments);
    assert_eq!(fork_state.system_prompt.as_deref(), Some("System prompt"));
 }

@@ -357,14 +449,15 @@ async fn session_fork_creates_new_session() {
 async fn session_fork_at_truncates_within_session() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(simple_text_events());
-    let worker = Engine::new(client);
+    let worker = TestWorker::new(Engine::new(client));

    let (sid, segid) = session_store::create_segment(
        &store,
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -378,7 +471,11 @@ async fn session_fork_at_truncates_within_session() {
    let fork_segid = session_store::fork_at(&store, sid, segid, worker.turn_count()).unwrap();

    let fork_entries = store.read_all(sid, fork_segid).unwrap();
-    assert_eq!(fork_entries.len(), 1); // Just the new SegmentStart
+    assert_eq!(fork_entries.len(), 2);
+    assert!(matches!(
+        &fork_entries[1],
+        LogEntry::InputSegmentsCheckpoint { .. }
+    ));

    let fork_state = collect_state(&fork_entries);
    assert_eq!(fork_state.session_id, Some(sid), "fork_at inherits Session");
@@ -390,7 +487,25 @@ async fn session_fork_at_truncates_within_session() {
        .position(|e| matches!(e, LogEntry::TurnEnd { turn_count, .. } if *turn_count == worker.turn_count()))
        .expect("source segment has the matching TurnEnd");
    let source_state_at_fork = collect_state(&all_entries[..=turn_end_pos]);
+    assert_eq!(fork_state.user_segments, source_state_at_fork.user_segments);
    assert_eq!(fork_state.history.len(), source_state_at_fork.history.len());
+    assert_eq!(
+        fork_state.annotated_history, source_state_at_fork.annotated_history,
+        "fork_at must preserve every retained history entry identity and provenance",
+    );
+    assert!(fork_state.annotated_history.iter().all(|entry| {
+        !entry.metadata.entry_id.0.is_empty()
+            && matches!(
+                entry.metadata.origin,
+                session_store::LoggedSessionHistoryOrigin::LegacyUnknown
+                    | session_store::LoggedSessionHistoryOrigin::HumanInput { .. }
+                    | session_store::LoggedSessionHistoryOrigin::WorkerInput { .. }
+                    | session_store::LoggedSessionHistoryOrigin::BackendInstruction { .. }
+                    | session_store::LoggedSessionHistoryOrigin::ModelOutput { .. }
+                    | session_store::LoggedSessionHistoryOrigin::ToolOutput { .. }
+                    | session_store::LoggedSessionHistoryOrigin::DerivedSummary
+            )
+    }));

    // list_segments should show both source and fork in the same Session.
    let segs = store.list_segments(sid).unwrap();
@@ -398,18 +513,97 @@ async fn session_fork_at_truncates_within_session() {
    assert!(segs.contains(&fork_segid));
 }

+#[test]
+fn rewound_fork_preserves_uploaded_file_segments_in_snapshot() {
+    let (_dir, store) = make_store();
+    let config = RequestConfig::default();
+    let (sid, segid) = session_store::create_segment(
+        &store,
+        SegmentStartState {
+            system_prompt: Some("System prompt"),
+            config: &config,
+            history: Vec::new(),
+            user_segments: Vec::new(),
+        },
+    )
+    .unwrap();
+    let uploaded = UploadedFileRef {
+        artifact_id: "uploaded-file-1".into(),
+        file_name: "notes.txt".into(),
+        media_type: "text/plain".into(),
+        created_at_ms: 123,
+        availability: UploadedFileAvailability::Available,
+        byte_len: 5,
+        sha256: "a".repeat(64),
+        source_entry_id: Some("entry-1".into()),
+    };
+    let segments = vec![Segment::UploadedFile {
+        file: uploaded.clone(),
+    }];
+    session_store::save_user_input(
+        &store,
+        sid,
+        segid,
+        segments.clone(),
+        annotated(&[Item::user_message(Segment::flatten_to_text(&segments))]),
+    )
+    .unwrap();
+    session_store::save_turn_end(&store, sid, segid, 1).unwrap();
+
+    let fork_segid = session_store::fork_at(&store, sid, segid, 1).unwrap();
+    let fork_entries = store.read_all(sid, fork_segid).unwrap();
+    let snapshot = session_store::public_snapshot::project_session_snapshot(sid, &fork_entries);
+
+    assert!(fork_entries.iter().any(|entry| matches!(
+        entry,
+        LogEntry::InputSegmentsCheckpoint { user_segments, .. }
+            if user_segments == &vec![segments.clone()]
+    )));
+    assert!(snapshot.entries.iter().any(|entry| matches!(
+        &entry.data,
+        SessionSnapshotEntryData::UserInput { segments: restored }
+            if restored == &segments
+    )));
+
+    let fork_state = collect_state(&fork_entries);
+    let (copied_session_id, copied_segment_id) = session_store::fork(
+        &store,
+        sid,
+        SegmentStartState {
+            system_prompt: fork_state.system_prompt.as_deref(),
+            config: &fork_state.config,
+            history: fork_state.annotated_history.clone(),
+            user_segments: fork_state.user_segments.clone(),
+        },
+    )
+    .unwrap();
+    let copied_entries = store
+        .read_all(copied_session_id, copied_segment_id)
+        .unwrap();
+    let copied_snapshot = session_store::public_snapshot::project_session_snapshot(
+        copied_session_id,
+        &copied_entries,
+    );
+    assert!(copied_snapshot.entries.iter().any(|entry| matches!(
+        &entry.data,
+        SessionSnapshotEntryData::UserInput { segments: restored }
+            if restored == &segments
+    )));
+}
+
 #[tokio::test]
 async fn session_config_changed_logged() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(vec![]);
-    let mut worker = Engine::new(client);
+    let mut worker = TestWorker::new(Engine::new(client));

    let (sid, segid) = session_store::create_segment(
        &store,
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -435,14 +629,15 @@ async fn session_auto_forks_on_conflict() {

    // Create a segment
    let client_a = MockLlmClient::new(simple_text_events());
-    let worker_a = Engine::new(client_a);
+    let worker_a = TestWorker::new(Engine::new(client_a));

    let (sid, original_segid) = session_store::create_segment(
        &store,
        SegmentStartState {
            system_prompt: worker_a.get_system_prompt(),
            config: worker_a.request_config(),
-            history: worker_a.history(),
+            history: annotated(&worker_a.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -451,12 +646,14 @@ async fn session_auto_forks_on_conflict() {
    let mut entries_written: usize = 1;

    // Simulate another Worker writing to the same segment behind our back.
-    let extra_entry = LogEntry::UserInput {
-        ts: 9999,
-        extensions: vec![],
-        segments: vec![protocol::Segment::text("Interloper")],
-    };
-    store.append(sid, original_segid, &extra_entry).unwrap();
+    session_store::save_user_input(
+        &store,
+        sid,
+        original_segid,
+        vec![protocol::Segment::text("Interloper")],
+        annotated(&[Item::user_message("Interloper")]),
+    )
+    .unwrap();

    // Now the on-disk count exceeds our tally — ensure_head_or_fork should auto-fork.
    session_store::ensure_head_or_fork(
@@ -468,7 +665,8 @@ async fn session_auto_forks_on_conflict() {
        SegmentStartState {
            system_prompt: worker_a.get_system_prompt(),
            config: worker_a.request_config(),
-            history: worker_a.history(),
+            history: annotated(&worker_a.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -489,7 +687,7 @@ async fn session_auto_forks_on_conflict() {
    // The new segment records its lineage forward via forked_from; the
    // source segment is left immutable (no terminal marker written back).
    match &fork_entries[0] {
-        LogEntry::SegmentStart {
+        LogEntry::AnnotatedSegmentStart {
            forked_from: Some(origin),
            ..
        } => {
@@ -509,7 +707,7 @@ async fn session_auto_forks_on_conflict() {
    );
    let has_interloper = original_entries
        .iter()
-        .any(|e| matches!(e, LogEntry::UserInput { .. }));
+        .any(|e| matches!(e, LogEntry::AnnotatedUserInput { .. }));
    assert!(has_interloper);
 }

@@ -520,14 +718,15 @@ async fn session_auto_forks_on_conflict() {
 async fn nested_past_fork_leaves_ancestors_immutable() {
    let (_dir, store) = make_store();
    let client = MockLlmClient::new(simple_text_events());
-    let worker = Engine::new(client);
+    let worker = TestWorker::new(Engine::new(client));

    let (sid, root_segid) = session_store::create_segment(
        &store,
        SegmentStartState {
            system_prompt: worker.get_system_prompt(),
            config: worker.request_config(),
-            history: worker.history(),
+            history: annotated(&worker.history()),
+            user_segments: Vec::new(),
        },
    )
    .unwrap();
@@ -558,13 +757,20 @@ async fn nested_past_fork_leaves_ancestors_immutable() {
    let fork1_entries = store.read_all(sid, fork1).unwrap();
    assert_eq!(
        fork1_entries.len(),
-        1,
-        "fork1 is just its SegmentStart seed"
+        2,
+        "fork1 stores its SegmentStart and typed input checkpoint"
    );

-    // fork2's lineage points at fork1, not the root.
-    match &store.read_all(sid, fork2).unwrap()[0] {
-        LogEntry::SegmentStart {
+    // fork2's lineage points at fork1, not the root, and the typed seed remains
+    // intact across the nested turn-zero fork.
+    let fork2_entries = store.read_all(sid, fork2).unwrap();
+    assert_eq!(fork2_entries.len(), 2);
+    assert_eq!(
+        collect_state(&fork2_entries).user_segments,
+        collect_state(&fork1_entries).user_segments
+    );
+    match &fork2_entries[0] {
+        LogEntry::AnnotatedSegmentStart {
            forked_from: Some(origin),
            ..
        } => assert_eq!(origin.segment_id, fork1),
@@ -0,0 +1,26 @@
+[package]
+name = "standalone"
+description = "In-process standalone Worker host"
+version = "0.1.0"
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+agen.workspace = true
+client.workspace = true
+fs4.workspace = true
+manifest.workspace = true
+protocol.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+session-store.workspace = true
+thiserror.workspace = true
+tokio = { workspace = true, features = ["rt", "sync", "time"] }
+uuid = { workspace = true, features = ["v7"] }
+worker.workspace = true
+
+[dev-dependencies]
+async-trait.workspace = true
+futures.workspace = true
+tempfile.workspace = true
+tokio = { workspace = true, features = ["macros", "rt-multi-thread", "time"] }
@@ -0,0 +1,544 @@
+use std::path::PathBuf;
+use std::time::Duration;
+
+use agen::llm_client::client::LlmClient;
+use client::Client;
+use client::transport::in_process::{Peer as InProcessPeer, Socket as InProcessSocket};
+use manifest::ScopeRule;
+use protocol::stream::{decode_method, encode_event};
+use protocol::{Event, Method, WorkerId};
+use session_store::{
+    CombinedStore, FsStore, FsWorkerStore, WorkerActiveSegmentRef, WorkerMetadataStore,
+};
+use thiserror::Error;
+use worker::bootstrap::{
+    WorkerBootstrap, WorkerBootstrapError, WorkerBootstrapLayout, bash_output_dir_for_worker_id,
+};
+use worker::controller::WorkerControllerTransport;
+use worker::ipc::protocol_session::{
+    WorkerProtocolSessionStreams, dispatch_worker_protocol_method, live_log_entry_event,
+    subscribe_worker_protocol_session,
+};
+use worker::runtime::worker_allocation::ScopeLockError;
+use worker::{BootstrappedWorker, WorkerError, WorkerFilesystemAuthority, WorkerWorkspaceContext};
+
+use crate::launch::ResolvedStandaloneLaunch;
+use crate::store::{
+    StaleLeasePolicy, StandaloneShutdownReason, StandaloneStoreError, StandaloneWorkerLease,
+    StandaloneWorkerRecord, StandaloneWorkerStore,
+};
+
+const DEFAULT_SHUTDOWN_TIMEOUT: Duration = Duration::from_secs(10);
+type StandaloneBackingStore = CombinedStore<FsStore, FsWorkerStore>;
+
+/// One client-owned top-level Worker and its standalone Worker authority.
+///
+/// The host deliberately exposes the existing typed Worker protocol rather than owning an
+/// HTTP/WebSocket server or creating Runtime/Workspace/Ticket/Workdir domain records.
+pub struct StandaloneHost {
+    handle: worker::WorkerHandle,
+    shutdown: Option<worker::controller::ShutdownReceiver>,
+    shutdown_timeout: Duration,
+    store: StandaloneWorkerStore,
+    worker_store: FsWorkerStore,
+    record: StandaloneWorkerRecord,
+    lease: Option<StandaloneWorkerLease>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum StandaloneStartupError {
+    #[error("the standalone state store could not be opened or validated")]
+    StateStore,
+    #[error("the standalone Worker is already active")]
+    WorkerActive,
+    #[error("the standalone Worker lease cannot be observed safely; recovery is rejected")]
+    LeaseLivenessUnknown,
+    #[error("the standalone Worker working directory is unavailable or changed")]
+    WorkingDirectoryUnavailable,
+    #[error(
+        "requested scope `{}` conflicts with worker allocation `{competitor}` rule `{}`",
+        requested_rule.target.display(),
+        competitor_rule.target.display()
+    )]
+    ScopeConflict {
+        competitor: String,
+        requested_rule: ScopeRule,
+        competitor_rule: ScopeRule,
+    },
+    #[error("the resolved Worker configuration or persisted history is invalid")]
+    WorkerConfiguration,
+    #[error("the configured model provider is unavailable")]
+    ModelProvider,
+    #[error("the fixed standalone feature composition could not be installed")]
+    FeatureComposition,
+    #[error("the in-process Worker controller could not start")]
+    Controller,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+pub enum StandaloneShutdownError {
+    #[error("the standalone Worker did not stop before the shutdown deadline")]
+    DeadlineExceeded,
+    #[error("the standalone Worker shutdown confirmation was lost")]
+    ConfirmationLost,
+    #[error("the standalone Worker final state could not be committed")]
+    StateStore,
+}
+
+impl StandaloneHost {
+    pub async fn start(launch: ResolvedStandaloneLaunch) -> Result<Self, StandaloneStartupError> {
+        Self::start_with_optional_model_client(launch, None).await
+    }
+
+    pub async fn start_with_model_client<C>(
+        launch: ResolvedStandaloneLaunch,
+        model_client: C,
+    ) -> Result<Self, StandaloneStartupError>
+    where
+        C: LlmClient + 'static,
+    {
+        Self::start_with_optional_model_client(launch, Some(Box::new(model_client))).await
+    }
+
+    async fn start_with_optional_model_client(
+        launch: ResolvedStandaloneLaunch,
+        model_client: Option<Box<dyn LlmClient>>,
+    ) -> Result<Self, StandaloneStartupError> {
+        let store =
+            StandaloneWorkerStore::open(&launch.state_dir).map_err(classify_store_startup_error)?;
+        let allocation = store
+            .allocate(&launch.cwd, StaleLeasePolicy::Reject)
+            .map_err(classify_store_startup_error)?;
+        let worker_id = allocation.worker_id();
+
+        // WorkerId is the stable identity. The current Worker store remains
+        // name-keyed, so keep its derived storage key separate from the
+        // user-facing profile name.
+        let manifest = launch.profile.manifest.clone();
+        let storage_key = format!("standalone-{worker_id}");
+        let mut bootstrap_manifest = manifest.clone();
+        bootstrap_manifest.worker.name = storage_key.clone();
+        let (backing_store, worker_store) = match backing_store(&store, worker_id) {
+            Ok(stores) => stores,
+            Err(error) => {
+                let _ = store.abandon_allocation(allocation);
+                return Err(error);
+            }
+        };
+        let filesystem_authority =
+            WorkerFilesystemAuthority::local(launch.cwd.clone(), launch.cwd.clone());
+        let workspace_context = WorkerWorkspaceContext::local_filesystem(None);
+        let runtime_base = store.runtime_dir(worker_id);
+        let bash_output_dir = bash_output_dir_for_worker_id(worker_id);
+
+        let mut bootstrap = WorkerBootstrap::new(
+            bootstrap_manifest,
+            backing_store,
+            launch.prompt_catalog,
+            workspace_context,
+            filesystem_authority,
+            WorkerBootstrapLayout::Direct {
+                runtime_base,
+                bash_output_dir,
+            },
+            WorkerControllerTransport::InProcess,
+        );
+        if let Some(model_client) = model_client {
+            bootstrap = bootstrap.with_model_client(model_client);
+        }
+        let started = match bootstrap.start().await {
+            Ok(started) => started,
+            Err(error) => {
+                let _ = store.abandon_allocation(allocation);
+                return Err(classify_startup_error(error));
+            }
+        };
+        let active = match active_pointer(&worker_store, &storage_key) {
+            Ok(active) => active,
+            Err(error) => {
+                stop_started_worker(started).await;
+                let _ = store.abandon_allocation(allocation);
+                return Err(error);
+            }
+        };
+        let record = match store.commit_created(
+            &allocation,
+            manifest,
+            storage_key,
+            active.session_id,
+            active.segment_id,
+        ) {
+            Ok(record) => record,
+            Err(_) => {
+                stop_started_worker(started).await;
+                let _ = store.abandon_allocation(allocation);
+                return Err(StandaloneStartupError::StateStore);
+            }
+        };
+        Ok(Self::from_started(
+            started,
+            store,
+            worker_store,
+            record,
+            allocation.into_lease(),
+        ))
+    }
+
+    pub async fn restore(
+        state_dir: PathBuf,
+        worker_id: WorkerId,
+    ) -> Result<Self, StandaloneStartupError> {
+        Self::restore_with_optional_model_client(state_dir, worker_id, None).await
+    }
+
+    pub async fn restore_with_model_client<C>(
+        state_dir: PathBuf,
+        worker_id: WorkerId,
+        model_client: C,
+    ) -> Result<Self, StandaloneStartupError>
+    where
+        C: LlmClient + 'static,
+    {
+        Self::restore_with_optional_model_client(state_dir, worker_id, Some(Box::new(model_client)))
+            .await
+    }
+
+    async fn restore_with_optional_model_client(
+        state_dir: PathBuf,
+        worker_id: WorkerId,
+        model_client: Option<Box<dyn LlmClient>>,
+    ) -> Result<Self, StandaloneStartupError> {
+        let store = StandaloneWorkerStore::open(state_dir).map_err(classify_store_startup_error)?;
+        let record = store
+            .load(worker_id)
+            .map_err(classify_store_startup_error)?;
+        record.cwd.verify().map_err(classify_store_startup_error)?;
+        let lease = store
+            .acquire_lease(worker_id, StaleLeasePolicy::Recover)
+            .map_err(classify_store_startup_error)?;
+        let (backing_store, worker_store) = backing_store(&store, worker_id)?;
+        let storage_key = record.storage_key.clone();
+        let mut manifest = record.manifest.clone();
+        manifest.worker.name = storage_key.clone();
+        let filesystem_authority = WorkerFilesystemAuthority::local(
+            record.cwd.canonical_path.clone(),
+            record.cwd.canonical_path.clone(),
+        );
+        let workspace_context = WorkerWorkspaceContext::local_filesystem(None);
+        let runtime_base = store.runtime_dir(worker_id);
+        let bash_output_dir = bash_output_dir_for_worker_id(worker_id);
+
+        let mut bootstrap = WorkerBootstrap::new(
+            manifest,
+            backing_store,
+            worker::PromptCatalogSource::builtins_only(),
+            workspace_context,
+            filesystem_authority,
+            WorkerBootstrapLayout::Direct {
+                runtime_base,
+                bash_output_dir,
+            },
+            WorkerControllerTransport::InProcess,
+        );
+        if let Some(model_client) = model_client {
+            bootstrap = bootstrap.with_model_client(model_client);
+        }
+        let prepared = bootstrap
+            .prepare_restored(&storage_key)
+            .await
+            .map_err(classify_startup_error)?;
+        let started = prepared.start().await.map_err(classify_startup_error)?;
+        let active = match active_pointer(&worker_store, &storage_key) {
+            Ok(active) => active,
+            Err(error) => {
+                stop_started_worker(started).await;
+                return Err(error);
+            }
+        };
+        let record =
+            match store.update_active_pointer(&record, active.session_id, active.segment_id) {
+                Ok(record) => record,
+                Err(_) => {
+                    stop_started_worker(started).await;
+                    lease.retain();
+                    return Err(StandaloneStartupError::StateStore);
+                }
+            };
+        Ok(Self::from_started(
+            started,
+            store,
+            worker_store,
+            record,
+            lease,
+        ))
+    }
+
+    fn from_started(
+        started: BootstrappedWorker,
+        store: StandaloneWorkerStore,
+        worker_store: FsWorkerStore,
+        record: StandaloneWorkerRecord,
+        lease: StandaloneWorkerLease,
+    ) -> Self {
+        Self {
+            handle: started.handle,
+            shutdown: Some(started.shutdown),
+            shutdown_timeout: DEFAULT_SHUTDOWN_TIMEOUT,
+            store,
+            worker_store,
+            record,
+            lease: Some(lease),
+        }
+    }
+
+    #[must_use]
+    pub fn worker_id(&self) -> WorkerId {
+        self.record.worker_id
+    }
+
+    #[must_use]
+    pub fn record(&self) -> &StandaloneWorkerRecord {
+        &self.record
+    }
+
+    /// Open one complete client-side Worker protocol session.
+    ///
+    /// Working events, committed session entries, alert snapshots, and the
+    /// initial history snapshot are merged behind the client boundary.
+    pub fn connect(&self) -> Client<InProcessSocket> {
+        let streams = subscribe_worker_protocol_session(&self.handle);
+        let (socket, peer) = InProcessSocket::pair();
+        tokio::spawn(run_protocol_session(self.handle.clone(), streams, peer));
+        Client::new(socket)
+    }
+
+    pub fn with_shutdown_timeout(mut self, shutdown_timeout: Duration) -> Self {
+        self.shutdown_timeout = shutdown_timeout;
+        self
+    }
+
+    pub async fn shutdown(mut self) -> Result<(), StandaloneShutdownError> {
+        let _ = self.handle.send(Method::Shutdown).await;
+        let Some(shutdown) = self.shutdown.take() else {
+            self.retain_lease();
+            return Err(StandaloneShutdownError::ConfirmationLost);
+        };
+        match tokio::time::timeout(self.shutdown_timeout, shutdown).await {
+            Ok(Ok(())) => {}
+            Ok(Err(_)) => {
+                self.retain_lease();
+                return Err(StandaloneShutdownError::ConfirmationLost);
+            }
+            Err(_) => {
+                self.retain_lease();
+                return Err(StandaloneShutdownError::DeadlineExceeded);
+            }
+        }
+        let active = match active_pointer(&self.worker_store, &self.record.storage_key) {
+            Ok(active) => active,
+            Err(_) => {
+                self.retain_lease();
+                return Err(StandaloneShutdownError::StateStore);
+            }
+        };
+        if self
+            .store
+            .mark_stopped(
+                &self.record,
+                active.session_id,
+                active.segment_id,
+                StandaloneShutdownReason::UserExit,
+            )
+            .is_err()
+        {
+            self.retain_lease();
+            return Err(StandaloneShutdownError::StateStore);
+        }
+        if let Some(lease) = self.lease.take() {
+            lease
+                .release()
+                .map_err(|_| StandaloneShutdownError::StateStore)?;
+        }
+        Ok(())
+    }
+
+    fn retain_lease(&mut self) {
+        if let Some(lease) = self.lease.take() {
+            lease.retain();
+        }
+    }
+}
+
+async fn run_protocol_session(
+    handle: worker::WorkerHandle,
+    streams: WorkerProtocolSessionStreams,
+    mut peer: InProcessPeer,
+) {
+    let WorkerProtocolSessionStreams {
+        snapshot_event,
+        mut log_entries,
+        alert_snapshot,
+        mut events,
+    } = streams;
+
+    if !send_protocol_snapshot(&peer, alert_snapshot, snapshot_event).await {
+        return;
+    }
+
+    loop {
+        tokio::select! {
+            message = peer.next() => {
+                let Some(message) = message else {
+                    return;
+                };
+                let Ok(method) = decode_method(&message) else {
+                    return;
+                };
+                if let Some(event) = dispatch_worker_protocol_method(&handle, method).await
+                    && !send_protocol_event(&peer, event).await
+                {
+                    return;
+                }
+            }
+            event = events.recv() => {
+                match event {
+                    Ok(event) => {
+                        if !send_protocol_event(&peer, event).await {
+                            return;
+                        }
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {
+                        let replacement = subscribe_worker_protocol_session(&handle);
+                        let WorkerProtocolSessionStreams {
+                            snapshot_event,
+                            log_entries: replacement_log_entries,
+                            alert_snapshot,
+                            events: replacement_events,
+                        } = replacement;
+                        log_entries = replacement_log_entries;
+                        events = replacement_events;
+                        if !send_protocol_snapshot(&peer, alert_snapshot, snapshot_event).await {
+                            return;
+                        }
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Closed) => return,
+                }
+            }
+            entry = log_entries.recv() => {
+                match entry {
+                    Ok(entry) => {
+                        if let Some(event) = live_log_entry_event(entry)
+                            && !send_protocol_event(&peer, event).await
+                        {
+                            return;
+                        }
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {
+                        let replacement = subscribe_worker_protocol_session(&handle);
+                        let WorkerProtocolSessionStreams {
+                            snapshot_event,
+                            log_entries: replacement_log_entries,
+                            alert_snapshot,
+                            events: replacement_events,
+                        } = replacement;
+                        log_entries = replacement_log_entries;
+                        events = replacement_events;
+                        if !send_protocol_snapshot(&peer, alert_snapshot, snapshot_event).await {
+                            return;
+                        }
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Closed) => return,
+                }
+            }
+        }
+    }
+}
+
+async fn send_protocol_snapshot(
+    peer: &InProcessPeer,
+    alert_snapshot: Vec<protocol::Alert>,
+    snapshot_event: Event,
+) -> bool {
+    for alert in alert_snapshot {
+        if !send_protocol_event(peer, Event::Alert(alert)).await {
+            return false;
+        }
+    }
+    send_protocol_event(peer, snapshot_event).await
+}
+
+async fn send_protocol_event(peer: &InProcessPeer, event: Event) -> bool {
+    let Ok(message) = encode_event(&event) else {
+        return false;
+    };
+    peer.send(message).await.is_ok()
+}
+
+fn backing_store(
+    store: &StandaloneWorkerStore,
+    worker_id: WorkerId,
+) -> Result<(StandaloneBackingStore, FsWorkerStore), StandaloneStartupError> {
+    let session_store = FsStore::new(store.sessions_dir(worker_id))
+        .map_err(|_| StandaloneStartupError::StateStore)?;
+    let worker_store = FsWorkerStore::new(store.worker_metadata_dir(worker_id))
+        .map_err(|_| StandaloneStartupError::StateStore)?;
+    Ok((
+        CombinedStore::new(session_store, worker_store.clone()),
+        worker_store,
+    ))
+}
+
+fn active_pointer(
+    worker_store: &FsWorkerStore,
+    storage_key: &str,
+) -> Result<WorkerActiveSegmentRef, StandaloneStartupError> {
+    worker_store
+        .read_by_name(storage_key)
+        .map_err(|_| StandaloneStartupError::StateStore)?
+        .and_then(|metadata| metadata.active)
+        .ok_or(StandaloneStartupError::StateStore)
+}
+
+async fn stop_started_worker(started: BootstrappedWorker) {
+    let _ = started.handle.send(Method::Shutdown).await;
+    let _ = tokio::time::timeout(Duration::from_secs(2), started.shutdown).await;
+}
+
+fn classify_store_startup_error(error: StandaloneStoreError) -> StandaloneStartupError {
+    match error {
+        StandaloneStoreError::WorkerLeased(_) => StandaloneStartupError::WorkerActive,
+        StandaloneStoreError::LeaseLivenessUnknown(_) => {
+            StandaloneStartupError::LeaseLivenessUnknown
+        }
+        StandaloneStoreError::CwdUnavailable(_)
+        | StandaloneStoreError::CwdNotDirectory
+        | StandaloneStoreError::CwdIdentityMismatch => {
+            StandaloneStartupError::WorkingDirectoryUnavailable
+        }
+        _ => StandaloneStartupError::StateStore,
+    }
+}
+
+fn classify_startup_error(error: WorkerBootstrapError) -> StandaloneStartupError {
+    match error {
+        WorkerBootstrapError::Worker(WorkerError::ScopeLock(ScopeLockError::WriteConflict {
+            competitor,
+            rule,
+            competitor_rule,
+        })) => StandaloneStartupError::ScopeConflict {
+            competitor,
+            requested_rule: rule,
+            competitor_rule,
+        },
+        WorkerBootstrapError::Worker(WorkerError::Provider(_)) => {
+            StandaloneStartupError::ModelProvider
+        }
+        WorkerBootstrapError::Worker(_) => StandaloneStartupError::WorkerConfiguration,
+        WorkerBootstrapError::Controller { source, .. }
+            if source.kind() == std::io::ErrorKind::Other =>
+        {
+            StandaloneStartupError::FeatureComposition
+        }
+        WorkerBootstrapError::Controller { .. } => StandaloneStartupError::Controller,
+    }
+}
@@ -0,0 +1,86 @@
+use std::path::{Path, PathBuf};
+
+use manifest::{
+    ProfileExecutionTarget, ProfileResolveOptions, ProfileResolver, ProfileSelector,
+    ResolvedProfile,
+};
+use thiserror::Error;
+use worker::PromptCatalogSource;
+
+/// Process launch input resolved before any Worker/session side effect occurs.
+#[derive(Debug, Clone)]
+pub struct StandaloneLaunchConfig {
+    pub cwd: PathBuf,
+    pub state_dir: PathBuf,
+    pub profile: ProfileSelector,
+    pub worker_name: String,
+}
+
+pub struct ResolvedStandaloneLaunch {
+    pub cwd: PathBuf,
+    pub state_dir: PathBuf,
+    pub profile: ResolvedProfile,
+    pub prompt_catalog: PromptCatalogSource,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+pub enum StandaloneLaunchError {
+    #[error("the standalone working directory is unavailable")]
+    WorkingDirectoryUnavailable,
+    #[error("path-based profiles are not standalone launch authority")]
+    PathProfileUnsupported,
+    #[error("the standalone profile could not be resolved")]
+    ProfileResolutionFailed,
+}
+
+impl StandaloneLaunchConfig {
+    pub fn new(
+        cwd: impl Into<PathBuf>,
+        state_dir: impl Into<PathBuf>,
+        profile: ProfileSelector,
+        worker_name: impl Into<String>,
+    ) -> Self {
+        Self {
+            cwd: cwd.into(),
+            state_dir: state_dir.into(),
+            profile,
+            worker_name: worker_name.into(),
+        }
+    }
+
+    /// Resolve only built-in/XDG profile authority and bind standalone scope
+    /// to the canonical process cwd. Repository-local profile discovery is
+    /// deliberately not part of this path.
+    pub fn resolve(self) -> Result<ResolvedStandaloneLaunch, StandaloneLaunchError> {
+        if matches!(self.profile, ProfileSelector::Path { .. }) {
+            return Err(StandaloneLaunchError::PathProfileUnsupported);
+        }
+        let cwd = canonical_directory(&self.cwd)?;
+        let profile = ProfileResolver::new()
+            .with_workspace_base(&cwd)
+            .resolve_for_target(
+                &self.profile,
+                ProfileResolveOptions {
+                    worker_name: Some(self.worker_name),
+                },
+                ProfileExecutionTarget::Standalone,
+            )
+            .map_err(|_| StandaloneLaunchError::ProfileResolutionFailed)?;
+
+        Ok(ResolvedStandaloneLaunch {
+            cwd,
+            state_dir: self.state_dir,
+            profile,
+            prompt_catalog: PromptCatalogSource::builtins_only(),
+        })
+    }
+}
+
+fn canonical_directory(path: &Path) -> Result<PathBuf, StandaloneLaunchError> {
+    let path = std::fs::canonicalize(path)
+        .map_err(|_| StandaloneLaunchError::WorkingDirectoryUnavailable)?;
+    if !path.is_dir() {
+        return Err(StandaloneLaunchError::WorkingDirectoryUnavailable);
+    }
+    Ok(path)
+}
@@ -0,0 +1,17 @@
+//! In-process standalone host for one top-level Yoi Worker.
+//!
+//! The crate composes existing `worker`, `manifest`, `session-store`, and
+//! `workdir` contracts. It intentionally owns no TUI, Runtime, Workspace
+//! Server, HTTP, WebSocket, subprocess Worker, or alternative execution path.
+
+pub mod host;
+pub mod launch;
+pub mod store;
+
+pub use host::{StandaloneHost, StandaloneShutdownError, StandaloneStartupError};
+pub use launch::{ResolvedStandaloneLaunch, StandaloneLaunchConfig, StandaloneLaunchError};
+pub use protocol::WorkerId;
+pub use store::{
+    StaleLeasePolicy, StandaloneCwdIdentity, StandaloneListScope, StandaloneShutdownReason,
+    StandaloneStoreError, StandaloneWorkerRecord, StandaloneWorkerStatus, StandaloneWorkerStore,
+};
@@ -0,0 +1,741 @@
+use std::fs::{self, File, OpenOptions};
+use std::io::{self, Write};
+use std::path::{Path, PathBuf};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use fs4::fs_std::FileExt;
+use manifest::WorkerManifest;
+use protocol::WorkerId;
+use serde::{Deserialize, Serialize};
+use session_store::{SegmentId, SessionId};
+use thiserror::Error;
+use uuid::Uuid;
+
+const RECORD_FILE: &str = "record.json";
+const COMMIT_MARKER: &str = "commit.pending";
+const LEASE_FILE: &str = "lease.json";
+const LEASE_LOCK_FILE: &str = "lease.lock";
+const SESSIONS_DIR: &str = "sessions";
+const WORKER_DIR: &str = "worker";
+const SCHEMA_VERSION: u32 = 1;
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct StandaloneCwdIdentity {
+    pub canonical_path: PathBuf,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub device: Option<u64>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub inode: Option<u64>,
+}
+
+impl StandaloneCwdIdentity {
+    pub fn capture(path: impl AsRef<Path>) -> Result<Self, StandaloneStoreError> {
+        let canonical_path =
+            fs::canonicalize(path).map_err(StandaloneStoreError::CwdUnavailable)?;
+        let metadata =
+            fs::metadata(&canonical_path).map_err(StandaloneStoreError::CwdUnavailable)?;
+        if !metadata.is_dir() {
+            return Err(StandaloneStoreError::CwdNotDirectory);
+        }
+        #[cfg(unix)]
+        let (device, inode) = {
+            use std::os::unix::fs::MetadataExt;
+            (Some(metadata.dev()), Some(metadata.ino()))
+        };
+        #[cfg(not(unix))]
+        let (device, inode) = (None, None);
+        Ok(Self {
+            canonical_path,
+            device,
+            inode,
+        })
+    }
+
+    pub fn verify(&self) -> Result<PathBuf, StandaloneStoreError> {
+        let current = Self::capture(&self.canonical_path)?;
+        if current != *self {
+            return Err(StandaloneStoreError::CwdIdentityMismatch);
+        }
+        Ok(current.canonical_path)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum StandaloneWorkerStatus {
+    Active,
+    Stopped,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum StandaloneShutdownReason {
+    UserExit,
+    StartupFailed,
+    ControllerError,
+    ProcessInterrupted,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StandaloneWorkerRecord {
+    pub schema_version: u32,
+    pub revision: u64,
+    pub worker_id: WorkerId,
+    /// User-facing Worker name resolved from the profile.
+    pub worker_name: String,
+    /// Internal key used by the current name-keyed Worker store.
+    pub storage_key: String,
+    pub cwd: StandaloneCwdIdentity,
+    pub manifest: WorkerManifest,
+    pub active_session_id: SessionId,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub active_segment_id: Option<SegmentId>,
+    pub status: StandaloneWorkerStatus,
+    pub created_at_unix_ms: u64,
+    pub updated_at_unix_ms: u64,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub shutdown_reason: Option<StandaloneShutdownReason>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum StandaloneListScope {
+    CurrentCwd,
+    All,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum StaleLeasePolicy {
+    Reject,
+    Recover,
+}
+
+#[derive(Debug, Clone)]
+pub struct StandaloneWorkerStore {
+    root: PathBuf,
+}
+
+impl StandaloneWorkerStore {
+    pub fn open(root: impl Into<PathBuf>) -> Result<Self, StandaloneStoreError> {
+        let root = root.into();
+        fs::create_dir_all(&root).map_err(StandaloneStoreError::Io)?;
+        if !fs::metadata(&root)
+            .map_err(StandaloneStoreError::Io)?
+            .is_dir()
+        {
+            return Err(StandaloneStoreError::NotDirectory);
+        }
+        Ok(Self { root })
+    }
+
+    #[must_use]
+    pub fn root(&self) -> &Path {
+        &self.root
+    }
+
+    pub fn allocate(
+        &self,
+        cwd: impl AsRef<Path>,
+        policy: StaleLeasePolicy,
+    ) -> Result<StandaloneWorkerAllocation, StandaloneStoreError> {
+        let worker_id = WorkerId::now_v7();
+        let cwd = StandaloneCwdIdentity::capture(cwd)?;
+        let dir = self.worker_dir(worker_id);
+        fs::create_dir(&dir).map_err(StandaloneStoreError::Io)?;
+        fs::create_dir(dir.join(SESSIONS_DIR)).map_err(StandaloneStoreError::Io)?;
+        fs::create_dir(dir.join(WORKER_DIR)).map_err(StandaloneStoreError::Io)?;
+        let lease = self.acquire_lease(worker_id, policy)?;
+        Ok(StandaloneWorkerAllocation {
+            worker_id,
+            cwd,
+            lease,
+        })
+    }
+
+    pub fn commit_created(
+        &self,
+        allocation: &StandaloneWorkerAllocation,
+        manifest: WorkerManifest,
+        storage_key: String,
+        active_session_id: SessionId,
+        active_segment_id: Option<SegmentId>,
+    ) -> Result<StandaloneWorkerRecord, StandaloneStoreError> {
+        let now = now_unix_ms()?;
+        let record = StandaloneWorkerRecord {
+            schema_version: SCHEMA_VERSION,
+            revision: 1,
+            worker_id: allocation.worker_id,
+            worker_name: manifest.worker.name.clone(),
+            storage_key,
+            cwd: allocation.cwd.clone(),
+            manifest,
+            active_session_id,
+            active_segment_id,
+            status: StandaloneWorkerStatus::Active,
+            created_at_unix_ms: now,
+            updated_at_unix_ms: now,
+            shutdown_reason: None,
+        };
+        self.commit_record(None, &record)?;
+        Ok(record)
+    }
+
+    pub fn load(&self, id: WorkerId) -> Result<StandaloneWorkerRecord, StandaloneStoreError> {
+        let dir = self.worker_dir(id);
+        if dir.join(COMMIT_MARKER).exists() {
+            return Err(StandaloneStoreError::IncompleteCommit(id));
+        }
+        let bytes = fs::read(dir.join(RECORD_FILE)).map_err(|error| {
+            if error.kind() == io::ErrorKind::NotFound {
+                StandaloneStoreError::WorkerNotFound(id)
+            } else {
+                StandaloneStoreError::Io(error)
+            }
+        })?;
+        let record: StandaloneWorkerRecord = serde_json::from_slice(&bytes)
+            .map_err(|source| StandaloneStoreError::CorruptRecord { id, source })?;
+        if record.schema_version > SCHEMA_VERSION {
+            return Err(StandaloneStoreError::NewerSchema {
+                id,
+                found: record.schema_version,
+                supported: SCHEMA_VERSION,
+            });
+        }
+        if record.schema_version != SCHEMA_VERSION || record.worker_id != id {
+            return Err(StandaloneStoreError::InvalidRecord(id));
+        }
+        Ok(record)
+    }
+
+    pub fn list(
+        &self,
+        cwd: impl AsRef<Path>,
+        scope: StandaloneListScope,
+        limit: usize,
+    ) -> Result<Vec<StandaloneWorkerRecord>, StandaloneStoreError> {
+        let current_cwd = (scope == StandaloneListScope::CurrentCwd)
+            .then(|| StandaloneCwdIdentity::capture(cwd))
+            .transpose()?;
+        let mut records = Vec::new();
+        for entry in fs::read_dir(&self.root).map_err(StandaloneStoreError::Io)? {
+            let entry = entry.map_err(StandaloneStoreError::Io)?;
+            if !entry
+                .file_type()
+                .map_err(StandaloneStoreError::Io)?
+                .is_dir()
+            {
+                continue;
+            }
+            let Ok(id) = entry.file_name().to_string_lossy().parse() else {
+                continue;
+            };
+            let record = self.load(id)?;
+            if current_cwd.as_ref().is_none_or(|cwd| &record.cwd == cwd) {
+                records.push(record);
+            }
+        }
+        records.sort_by(|left, right| {
+            right
+                .updated_at_unix_ms
+                .cmp(&left.updated_at_unix_ms)
+                .then_with(|| right.worker_id.to_string().cmp(&left.worker_id.to_string()))
+        });
+        records.truncate(limit);
+        Ok(records)
+    }
+
+    pub fn acquire_lease(
+        &self,
+        id: WorkerId,
+        policy: StaleLeasePolicy,
+    ) -> Result<StandaloneWorkerLease, StandaloneStoreError> {
+        let dir = self.worker_dir(id);
+        let path = dir.join(LEASE_FILE);
+        let _guard = LeaseMutationGuard::acquire(&dir)?;
+        let lease = LeaseRecord::current()?;
+        loop {
+            match OpenOptions::new().write(true).create_new(true).open(&path) {
+                Ok(mut file) => {
+                    serde_json::to_writer(&mut file, &lease).map_err(StandaloneStoreError::Json)?;
+                    file.write_all(b"\n").map_err(StandaloneStoreError::Io)?;
+                    file.sync_all().map_err(StandaloneStoreError::Io)?;
+                    sync_directory(&dir)?;
+                    return Ok(StandaloneWorkerLease {
+                        path,
+                        lease_id: lease.lease_id,
+                        released: false,
+                    });
+                }
+                Err(error) if error.kind() == io::ErrorKind::AlreadyExists => {
+                    let existing = read_lease(&path, id)?;
+                    match existing.liveness() {
+                        LeaseLiveness::Live => {
+                            return Err(StandaloneStoreError::WorkerLeased(id));
+                        }
+                        LeaseLiveness::Unknown => {
+                            return Err(StandaloneStoreError::LeaseLivenessUnknown(id));
+                        }
+                        LeaseLiveness::Stale => {}
+                    }
+                    if policy == StaleLeasePolicy::Reject {
+                        return Err(StandaloneStoreError::StaleLease(id));
+                    }
+                    fs::remove_file(&path).map_err(StandaloneStoreError::Io)?;
+                    sync_directory(&dir)?;
+                }
+                Err(error) => return Err(StandaloneStoreError::Io(error)),
+            }
+        }
+    }
+
+    pub fn update_active_pointer(
+        &self,
+        record: &StandaloneWorkerRecord,
+        active_session_id: SessionId,
+        active_segment_id: Option<SegmentId>,
+    ) -> Result<StandaloneWorkerRecord, StandaloneStoreError> {
+        let mut next = record.clone();
+        next.revision = next.revision.saturating_add(1);
+        next.updated_at_unix_ms = now_unix_ms()?;
+        next.active_session_id = active_session_id;
+        next.active_segment_id = active_segment_id;
+        next.status = StandaloneWorkerStatus::Active;
+        next.shutdown_reason = None;
+        self.commit_record(Some(record.revision), &next)?;
+        Ok(next)
+    }
+
+    pub fn mark_stopped(
+        &self,
+        record: &StandaloneWorkerRecord,
+        active_session_id: SessionId,
+        active_segment_id: Option<SegmentId>,
+        reason: StandaloneShutdownReason,
+    ) -> Result<StandaloneWorkerRecord, StandaloneStoreError> {
+        let mut next = record.clone();
+        next.revision = next.revision.saturating_add(1);
+        next.updated_at_unix_ms = now_unix_ms()?;
+        next.active_session_id = active_session_id;
+        next.active_segment_id = active_segment_id;
+        next.status = StandaloneWorkerStatus::Stopped;
+        next.shutdown_reason = Some(reason);
+        self.commit_record(Some(record.revision), &next)?;
+        Ok(next)
+    }
+
+    pub fn delete(&self, id: WorkerId) -> Result<(), StandaloneStoreError> {
+        let record = self.load(id)?;
+        if record.status != StandaloneWorkerStatus::Stopped {
+            return Err(StandaloneStoreError::DeleteActive(id));
+        }
+        let worker_dir = self.worker_dir(id);
+        let _guard = LeaseMutationGuard::acquire(&worker_dir)?;
+        let lease_path = worker_dir.join(LEASE_FILE);
+        if lease_path.exists() {
+            let lease = read_lease(&lease_path, id)?;
+            return Err(match lease.liveness() {
+                LeaseLiveness::Live => StandaloneStoreError::WorkerLeased(id),
+                LeaseLiveness::Stale => StandaloneStoreError::StaleLease(id),
+                LeaseLiveness::Unknown => StandaloneStoreError::LeaseLivenessUnknown(id),
+            });
+        }
+        fs::remove_dir_all(self.worker_dir(id)).map_err(StandaloneStoreError::Io)?;
+        sync_directory(&self.root)
+    }
+
+    #[must_use]
+    pub fn sessions_dir(&self, id: WorkerId) -> PathBuf {
+        self.worker_dir(id).join(SESSIONS_DIR)
+    }
+
+    #[must_use]
+    pub fn worker_metadata_dir(&self, id: WorkerId) -> PathBuf {
+        self.worker_dir(id).join(WORKER_DIR)
+    }
+
+    #[must_use]
+    pub(crate) fn runtime_dir(&self, id: WorkerId) -> PathBuf {
+        self.worker_dir(id).join("runtime")
+    }
+
+    pub(crate) fn abandon_allocation(
+        &self,
+        allocation: StandaloneWorkerAllocation,
+    ) -> Result<(), StandaloneStoreError> {
+        let worker_id = allocation.worker_id;
+        allocation.lease.release()?;
+        fs::remove_dir_all(self.worker_dir(worker_id)).map_err(StandaloneStoreError::Io)?;
+        sync_directory(&self.root)
+    }
+
+    fn commit_record(
+        &self,
+        expected_revision: Option<u64>,
+        next: &StandaloneWorkerRecord,
+    ) -> Result<(), StandaloneStoreError> {
+        let dir = self.worker_dir(next.worker_id);
+        let marker = dir.join(COMMIT_MARKER);
+        let mut marker_file = OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .open(&marker)
+            .map_err(|error| {
+                if error.kind() == io::ErrorKind::AlreadyExists {
+                    StandaloneStoreError::IncompleteCommit(next.worker_id)
+                } else {
+                    StandaloneStoreError::Io(error)
+                }
+            })?;
+        writeln!(marker_file, "{}", next.revision).map_err(StandaloneStoreError::Io)?;
+        marker_file.sync_all().map_err(StandaloneStoreError::Io)?;
+        sync_directory(&dir)?;
+
+        if let Some(expected) = expected_revision {
+            let current = self.load_record_while_committing(next.worker_id)?;
+            if current.revision != expected {
+                let _ = fs::remove_file(&marker);
+                return Err(StandaloneStoreError::RevisionConflict {
+                    id: next.worker_id,
+                    expected,
+                    found: current.revision,
+                });
+            }
+        }
+
+        let temporary = dir.join(format!("record.{}.tmp", Uuid::now_v7()));
+        let result = (|| {
+            let mut file = OpenOptions::new()
+                .write(true)
+                .create_new(true)
+                .open(&temporary)
+                .map_err(StandaloneStoreError::Io)?;
+            serde_json::to_writer_pretty(&mut file, next).map_err(StandaloneStoreError::Json)?;
+            file.write_all(b"\n").map_err(StandaloneStoreError::Io)?;
+            file.sync_all().map_err(StandaloneStoreError::Io)?;
+            fs::rename(&temporary, dir.join(RECORD_FILE)).map_err(StandaloneStoreError::Io)?;
+            sync_directory(&dir)?;
+            fs::remove_file(&marker).map_err(StandaloneStoreError::Io)?;
+            sync_directory(&dir)
+        })();
+        if result.is_err() {
+            let _ = fs::remove_file(&temporary);
+        }
+        result
+    }
+
+    fn load_record_while_committing(
+        &self,
+        id: WorkerId,
+    ) -> Result<StandaloneWorkerRecord, StandaloneStoreError> {
+        let bytes =
+            fs::read(self.worker_dir(id).join(RECORD_FILE)).map_err(StandaloneStoreError::Io)?;
+        serde_json::from_slice(&bytes)
+            .map_err(|source| StandaloneStoreError::CorruptRecord { id, source })
+    }
+
+    fn worker_dir(&self, id: WorkerId) -> PathBuf {
+        self.root.join(id.to_string())
+    }
+}
+
+#[derive(Debug)]
+pub struct StandaloneWorkerAllocation {
+    worker_id: WorkerId,
+    cwd: StandaloneCwdIdentity,
+    lease: StandaloneWorkerLease,
+}
+
+impl StandaloneWorkerAllocation {
+    #[must_use]
+    pub fn worker_id(&self) -> WorkerId {
+        self.worker_id
+    }
+
+    #[must_use]
+    pub fn cwd(&self) -> &StandaloneCwdIdentity {
+        &self.cwd
+    }
+
+    pub fn into_lease(self) -> StandaloneWorkerLease {
+        self.lease
+    }
+}
+
+#[derive(Debug)]
+pub struct StandaloneWorkerLease {
+    path: PathBuf,
+    lease_id: Uuid,
+    released: bool,
+}
+
+impl StandaloneWorkerLease {
+    pub fn release(mut self) -> Result<(), StandaloneStoreError> {
+        self.release_inner()
+    }
+
+    pub(crate) fn retain(mut self) {
+        self.released = true;
+    }
+
+    fn release_inner(&mut self) -> Result<(), StandaloneStoreError> {
+        if self.released {
+            return Ok(());
+        }
+        if self.path.exists() {
+            let parent = self.path.parent().expect("lease parent");
+            let _guard = LeaseMutationGuard::acquire(parent)?;
+            let bytes = fs::read(&self.path).map_err(StandaloneStoreError::Io)?;
+            let current: LeaseRecord =
+                serde_json::from_slice(&bytes).map_err(StandaloneStoreError::Json)?;
+            if current.lease_id != self.lease_id {
+                return Err(StandaloneStoreError::LeaseOwnershipLost);
+            }
+            fs::remove_file(&self.path).map_err(StandaloneStoreError::Io)?;
+            sync_directory(self.path.parent().expect("lease parent"))?;
+        }
+        self.released = true;
+        Ok(())
+    }
+}
+
+impl Drop for StandaloneWorkerLease {
+    fn drop(&mut self) {
+        let _ = self.release_inner();
+    }
+}
+
+struct LeaseMutationGuard {
+    file: File,
+}
+
+impl LeaseMutationGuard {
+    fn acquire(dir: &Path) -> Result<Self, StandaloneStoreError> {
+        let file = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(dir.join(LEASE_LOCK_FILE))
+            .map_err(StandaloneStoreError::Io)?;
+        file.lock_exclusive().map_err(StandaloneStoreError::Io)?;
+        Ok(Self { file })
+    }
+}
+
+impl Drop for LeaseMutationGuard {
+    fn drop(&mut self) {
+        let _ = FileExt::unlock(&self.file);
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct LeaseRecord {
+    lease_id: Uuid,
+    pid: u32,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    process_start_marker: Option<u64>,
+    acquired_at_unix_ms: u64,
+}
+
+impl LeaseRecord {
+    fn current() -> Result<Self, StandaloneStoreError> {
+        Ok(Self {
+            lease_id: Uuid::now_v7(),
+            pid: std::process::id(),
+            process_start_marker: match observe_process(std::process::id()) {
+                ProcessObservation::Running { start_marker } => Some(start_marker),
+                ProcessObservation::Missing | ProcessObservation::Unobservable => None,
+            },
+            acquired_at_unix_ms: now_unix_ms()?,
+        })
+    }
+
+    fn liveness(&self) -> LeaseLiveness {
+        classify_lease_liveness(self.process_start_marker, observe_process(self.pid))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum LeaseLiveness {
+    Live,
+    Stale,
+    Unknown,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum ProcessObservation {
+    Running { start_marker: u64 },
+    Missing,
+    Unobservable,
+}
+
+fn classify_lease_liveness(
+    recorded_start_marker: Option<u64>,
+    observation: ProcessObservation,
+) -> LeaseLiveness {
+    match (recorded_start_marker, observation) {
+        (Some(recorded), ProcessObservation::Running { start_marker })
+            if recorded == start_marker =>
+        {
+            LeaseLiveness::Live
+        }
+        (Some(_), ProcessObservation::Running { .. }) | (_, ProcessObservation::Missing) => {
+            LeaseLiveness::Stale
+        }
+        (None, ProcessObservation::Running { .. }) | (_, ProcessObservation::Unobservable) => {
+            LeaseLiveness::Unknown
+        }
+    }
+}
+
+fn read_lease(path: &Path, id: WorkerId) -> Result<LeaseRecord, StandaloneStoreError> {
+    let bytes = fs::read(path).map_err(StandaloneStoreError::Io)?;
+    serde_json::from_slice(&bytes)
+        .map_err(|source| StandaloneStoreError::CorruptLease { id, source })
+}
+
+#[cfg(target_os = "linux")]
+fn observe_process(pid: u32) -> ProcessObservation {
+    let stat = match fs::read_to_string(format!("/proc/{pid}/stat")) {
+        Ok(stat) => stat,
+        Err(error) if error.kind() == io::ErrorKind::NotFound => {
+            return if pid != std::process::id() && linux_proc_is_observable() {
+                ProcessObservation::Missing
+            } else {
+                ProcessObservation::Unobservable
+            };
+        }
+        Err(_) => return ProcessObservation::Unobservable,
+    };
+    parse_linux_process_start_marker(&stat)
+        .map(|start_marker| ProcessObservation::Running { start_marker })
+        .unwrap_or(ProcessObservation::Unobservable)
+}
+
+#[cfg(target_os = "linux")]
+fn linux_proc_is_observable() -> bool {
+    fs::read_to_string("/proc/self/stat")
+        .ok()
+        .and_then(|stat| parse_linux_process_start_marker(&stat))
+        .is_some()
+}
+
+#[cfg(target_os = "linux")]
+fn parse_linux_process_start_marker(stat: &str) -> Option<u64> {
+    let (_, tail) = stat.rsplit_once(") ")?;
+    tail.split_whitespace().nth(19)?.parse().ok()
+}
+
+#[cfg(not(target_os = "linux"))]
+fn observe_process(pid: u32) -> ProcessObservation {
+    if pid == std::process::id() {
+        ProcessObservation::Running { start_marker: 0 }
+    } else {
+        ProcessObservation::Unobservable
+    }
+}
+
+fn now_unix_ms() -> Result<u64, StandaloneStoreError> {
+    let duration = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_err(|_| StandaloneStoreError::Clock)?;
+    u64::try_from(duration.as_millis()).map_err(|_| StandaloneStoreError::Clock)
+}
+
+fn sync_directory(path: &Path) -> Result<(), StandaloneStoreError> {
+    File::open(path)
+        .and_then(|file| file.sync_all())
+        .map_err(StandaloneStoreError::Io)
+}
+
+#[derive(Debug, Error)]
+pub enum StandaloneStoreError {
+    #[error("standalone state path is not a directory")]
+    NotDirectory,
+    #[error("standalone cwd is unavailable")]
+    CwdUnavailable(#[source] io::Error),
+    #[error("standalone cwd is not a directory")]
+    CwdNotDirectory,
+    #[error("standalone cwd identity no longer matches the persisted Worker")]
+    CwdIdentityMismatch,
+    #[error("standalone Worker {0} was not found")]
+    WorkerNotFound(WorkerId),
+    #[error("standalone Worker {0} has an incomplete metadata commit")]
+    IncompleteCommit(WorkerId),
+    #[error("standalone Worker {0} has invalid metadata")]
+    InvalidRecord(WorkerId),
+    #[error("standalone Worker {id} metadata is corrupt")]
+    CorruptRecord {
+        id: WorkerId,
+        #[source]
+        source: serde_json::Error,
+    },
+    #[error("standalone Worker {id} lease is corrupt")]
+    CorruptLease {
+        id: WorkerId,
+        #[source]
+        source: serde_json::Error,
+    },
+    #[error("standalone Worker {id} uses schema {found}, newer than supported schema {supported}")]
+    NewerSchema {
+        id: WorkerId,
+        found: u32,
+        supported: u32,
+    },
+    #[error("standalone Worker {0} is already active")]
+    WorkerLeased(WorkerId),
+    #[error("standalone Worker {0} lease liveness cannot be proven; recovery is rejected")]
+    LeaseLivenessUnknown(WorkerId),
+    #[error("standalone Worker {0} has a stale lease; explicit recovery is required")]
+    StaleLease(WorkerId),
+    #[error("standalone Worker lease ownership changed")]
+    LeaseOwnershipLost,
+    #[error("standalone Worker {0} must be stopped before deletion")]
+    DeleteActive(WorkerId),
+    #[error(
+        "standalone Worker {id} metadata revision changed (expected {expected}, found {found})"
+    )]
+    RevisionConflict {
+        id: WorkerId,
+        expected: u64,
+        found: u64,
+    },
+    #[error("system clock is before the Unix epoch or out of range")]
+    Clock,
+    #[error("standalone metadata serialization failed")]
+    Json(#[source] serde_json::Error),
+    #[error("standalone state I/O failed")]
+    Io(#[source] io::Error),
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{LeaseLiveness, ProcessObservation, classify_lease_liveness};
+
+    #[test]
+    fn lease_liveness_requires_positive_live_or_stale_evidence() {
+        assert_eq!(
+            classify_lease_liveness(Some(41), ProcessObservation::Running { start_marker: 41 }),
+            LeaseLiveness::Live
+        );
+        assert_eq!(
+            classify_lease_liveness(Some(41), ProcessObservation::Running { start_marker: 42 }),
+            LeaseLiveness::Stale
+        );
+        assert_eq!(
+            classify_lease_liveness(Some(41), ProcessObservation::Missing),
+            LeaseLiveness::Stale
+        );
+        assert_eq!(
+            classify_lease_liveness(None, ProcessObservation::Running { start_marker: 41 }),
+            LeaseLiveness::Unknown
+        );
+        assert_eq!(
+            classify_lease_liveness(Some(41), ProcessObservation::Unobservable),
+            LeaseLiveness::Unknown
+        );
+        assert_eq!(
+            classify_lease_liveness(None, ProcessObservation::Unobservable),
+            LeaseLiveness::Unknown
+        );
+    }
+}
@@ -0,0 +1,612 @@
+use std::collections::VecDeque;
+use std::pin::Pin;
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use agen::llm_client::client::LlmClient;
+use agen::llm_client::error::ClientError;
+use agen::llm_client::event::{Event as LlmEvent, StopReason};
+use agen::llm_client::types::Request;
+use async_trait::async_trait;
+use client::Client;
+use client::transport::in_process::Socket as InProcessSocket;
+use futures::{Stream, stream};
+use protocol::{Event, Method};
+use standalone::{
+    StaleLeasePolicy, StandaloneHost, StandaloneLaunchConfig, StandaloneListScope,
+    StandaloneStartupError, StandaloneStoreError, StandaloneWorkerStatus, StandaloneWorkerStore,
+};
+use uuid::Uuid;
+
+#[derive(Clone)]
+struct ScriptedClient {
+    responses: Arc<Mutex<VecDeque<Vec<LlmEvent>>>>,
+    requests: Arc<Mutex<Vec<Request>>>,
+}
+
+impl ScriptedClient {
+    fn new(responses: Vec<Vec<LlmEvent>>) -> Self {
+        Self {
+            responses: Arc::new(Mutex::new(responses.into())),
+            requests: Arc::new(Mutex::new(Vec::new())),
+        }
+    }
+
+    fn requests(&self) -> Vec<Request> {
+        self.requests.lock().expect("requests lock").clone()
+    }
+}
+
+#[async_trait]
+impl LlmClient for ScriptedClient {
+    async fn stream(
+        &self,
+        request: Request,
+    ) -> Result<Pin<Box<dyn Stream<Item = Result<LlmEvent, ClientError>> + Send>>, ClientError>
+    {
+        self.requests.lock().expect("requests lock").push(request);
+        let response = self
+            .responses
+            .lock()
+            .expect("responses lock")
+            .pop_front()
+            .expect("scripted response");
+        Ok(Box::pin(stream::iter(response.into_iter().map(Ok))))
+    }
+
+    fn clone_boxed(&self) -> Box<dyn LlmClient> {
+        Box::new(self.clone())
+    }
+}
+
+#[tokio::test]
+async fn in_process_host_runs_text_and_read_tool_then_shuts_down() {
+    let temp = tempfile::tempdir().expect("tempdir");
+    std::fs::write(temp.path().join("probe.txt"), "standalone tool evidence\n")
+        .expect("write probe");
+    let worker_name = format!("standalone-{}", Uuid::now_v7());
+    let launch = StandaloneLaunchConfig::new(
+        temp.path(),
+        temp.path().join("state"),
+        manifest::ProfileSelector::Default,
+        &worker_name,
+    )
+    .resolve()
+    .expect("resolve standalone profile");
+
+    let client = ScriptedClient::new(vec![
+        vec![
+            LlmEvent::tool_use_start(0, "read-1", "Read"),
+            LlmEvent::tool_input_delta(0, r#"{"file_path":"probe.txt"}"#),
+            LlmEvent::tool_use_stop(0),
+        ],
+        vec![
+            LlmEvent::text_block_start(0),
+            LlmEvent::text_delta(0, "standalone response"),
+            LlmEvent::text_block_stop(0, Some(StopReason::EndTurn)),
+        ],
+    ]);
+    let inspection = client.clone();
+    let host = StandaloneHost::start_with_model_client(launch, client)
+        .await
+        .expect("start in-process host");
+    assert_eq!(host.record().worker_name, worker_name);
+    assert_eq!(host.record().manifest.worker.name, worker_name);
+    assert_eq!(
+        host.record().storage_key,
+        format!("standalone-{}", host.worker_id())
+    );
+    let mut protocol_client = host.connect();
+
+    protocol_client
+        .send(&Method::run_text("read the probe"))
+        .await
+        .expect("submit input");
+
+    tokio::time::timeout(Duration::from_secs(30), async {
+        let mut saw_user_message = false;
+        let mut saw_text = false;
+        let mut saw_tool_result = false;
+        loop {
+            match protocol_client
+                .next_event()
+                .await
+                .expect("protocol event")
+                .expect("worker event")
+            {
+                Event::UserMessage { segments }
+                    if format!("{segments:?}").contains("read the probe") =>
+                {
+                    saw_user_message = true;
+                }
+                Event::TextDelta { text } if text.contains("standalone response") => {
+                    saw_text = true;
+                }
+                Event::ToolResult { .. } => {
+                    saw_tool_result = true;
+                }
+                Event::RunEnd { .. } => {
+                    assert!(
+                        saw_user_message,
+                        "stream must expose the committed user message"
+                    );
+                    assert!(saw_text, "stream must expose the model text delta");
+                    assert!(saw_tool_result, "stream must expose the tool result");
+                    break;
+                }
+                _ => {}
+            }
+        }
+    })
+    .await
+    .expect("run completed");
+
+    let requests = inspection.requests();
+    assert_eq!(requests.len(), 2);
+    let tool_names = requests[0]
+        .tools
+        .iter()
+        .map(|tool| tool.name.as_str())
+        .collect::<Vec<_>>();
+    assert!(tool_names.contains(&"Read"));
+    assert!(tool_names.contains(&"TaskCreate"));
+    assert!(tool_names.contains(&"SubWorkerSpawn"));
+    assert!(format!("{:?}", requests[1].items).contains("standalone tool evidence"));
+    assert!(
+        !temp
+            .path()
+            .join("state/runtime")
+            .join(&worker_name)
+            .join("worker.sock")
+            .exists()
+    );
+
+    host.shutdown().await.expect("graceful shutdown");
+}
+
+#[tokio::test]
+async fn startup_preserves_occupied_scope_conflict_details() {
+    let temp = tempfile::tempdir().expect("tempdir");
+    let cwd = temp.path().join("project");
+    std::fs::create_dir(&cwd).expect("create project");
+
+    let first_launch = StandaloneLaunchConfig::new(
+        &cwd,
+        temp.path().join("first-state"),
+        manifest::ProfileSelector::Default,
+        "first-worker",
+    )
+    .resolve()
+    .expect("resolve first launch");
+    let first_host =
+        StandaloneHost::start_with_model_client(first_launch, ScriptedClient::new(Vec::new()))
+            .await
+            .expect("start first host");
+    let competitor = first_host.record().storage_key.clone();
+
+    let second_launch = StandaloneLaunchConfig::new(
+        &cwd,
+        temp.path().join("second-state"),
+        manifest::ProfileSelector::Default,
+        "second-worker",
+    )
+    .resolve()
+    .expect("resolve second launch");
+    let error =
+        StandaloneHost::start_with_model_client(second_launch, ScriptedClient::new(Vec::new()))
+            .await
+            .err()
+            .expect("occupied scope rejected");
+
+    first_host.shutdown().await.expect("shutdown first host");
+
+    let canonical_cwd = cwd.canonicalize().expect("canonical cwd");
+    match &error {
+        StandaloneStartupError::ScopeConflict {
+            competitor: actual_competitor,
+            requested_rule,
+            competitor_rule,
+        } => {
+            assert_eq!(actual_competitor, &competitor);
+            assert_eq!(requested_rule.target, canonical_cwd);
+            assert_eq!(competitor_rule.target, canonical_cwd);
+        }
+        other => panic!("expected scope conflict, got {other:?}"),
+    }
+    assert_eq!(
+        error.to_string(),
+        format!(
+            "requested scope `{}` conflicts with worker allocation `{competitor}` rule `{}`",
+            canonical_cwd.display(),
+            canonical_cwd.display()
+        )
+    );
+}
+
+#[tokio::test]
+async fn state_store_failure_is_redacted_and_starts_no_controller() {
+    let temp = tempfile::tempdir().expect("tempdir");
+    let state_path = temp.path().join("state-file-with-secret-name");
+    std::fs::write(&state_path, "not a directory").expect("write blocking file");
+    let launch = StandaloneLaunchConfig::new(
+        temp.path(),
+        &state_path,
+        manifest::ProfileSelector::Default,
+        format!("standalone-failure-{}", Uuid::now_v7()),
+    )
+    .resolve()
+    .expect("resolve launch");
+    let client = ScriptedClient::new(Vec::new());
+
+    let error = StandaloneHost::start_with_model_client(launch, client)
+        .await
+        .err()
+        .expect("state store startup rejected");
+    assert_eq!(error, standalone::StandaloneStartupError::StateStore);
+    assert_eq!(
+        error.to_string(),
+        "the standalone state store could not be opened or validated"
+    );
+    assert!(!error.to_string().contains("secret-name"));
+    assert!(
+        !temp
+            .path()
+            .join("state-file-with-secret-name/runtime")
+            .exists()
+    );
+}
+
+#[test]
+fn standalone_crate_has_no_tui_runtime_or_workspace_server_dependency() {
+    let manifest = include_str!("../Cargo.toml");
+    let dependencies = manifest
+        .split("[dependencies]")
+        .nth(1)
+        .expect("dependencies section")
+        .split("[dev-dependencies]")
+        .next()
+        .expect("dependency body");
+    for forbidden in ["tui", "worker-runtime", "yoi-workspace-server"] {
+        assert!(
+            !dependencies.lines().any(|line| {
+                line.split_once('=')
+                    .is_some_and(|(name, _)| name.trim() == forbidden)
+            }),
+            "standalone must not depend on {forbidden}"
+        );
+    }
+}
+
+#[test]
+fn launch_rejects_path_profile_before_worker_startup() {
+    let temp = tempfile::tempdir().expect("tempdir");
+    let error = StandaloneLaunchConfig::new(
+        temp.path(),
+        temp.path().join("state"),
+        manifest::ProfileSelector::Path {
+            path: temp.path().join("profile.dcdl"),
+        },
+        "standalone-path-profile",
+    )
+    .resolve()
+    .err()
+    .expect("path profile rejected");
+    assert_eq!(
+        error,
+        standalone::StandaloneLaunchError::PathProfileUnsupported
+    );
+}
+
+type TestResult = Result<(), Box<dyn std::error::Error>>;
+
+#[tokio::test]
+async fn standalone_restore_preserves_history_tasks_notifications_and_cwd_scope() -> TestResult {
+    let temp = tempfile::tempdir()?;
+    let cwd = temp.path().join("project");
+    let state_dir = temp.path().join("client").join("standalone-workers");
+    std::fs::create_dir_all(&cwd)?;
+    let launch = StandaloneLaunchConfig::new(
+        &cwd,
+        &state_dir,
+        manifest::ProfileSelector::Default,
+        "display-name-is-not-session-identity",
+    )
+    .resolve()?;
+    let first_client = ScriptedClient::new(vec![
+        vec![
+            LlmEvent::tool_use_start(0, "task-1", "TaskCreate"),
+            LlmEvent::tool_input_delta(
+                0,
+                r#"{"subject":"persisted task","description":"survives restore"}"#,
+            ),
+            LlmEvent::tool_use_stop(0),
+        ],
+        vec![
+            LlmEvent::text_block_start(0),
+            LlmEvent::text_delta(0, "first answer"),
+            LlmEvent::text_block_stop(0, Some(StopReason::EndTurn)),
+        ],
+        vec![
+            LlmEvent::text_block_start(0),
+            LlmEvent::text_delta(0, "notification acknowledged"),
+            LlmEvent::text_block_stop(0, Some(StopReason::EndTurn)),
+        ],
+    ]);
+    let host = StandaloneHost::start_with_model_client(launch, first_client).await?;
+    let worker_id = host.worker_id();
+    let mut protocol_client = host.connect();
+    protocol_client
+        .send(&Method::run_text("first request"))
+        .await?;
+    wait_for_run_end(&mut protocol_client).await?;
+    protocol_client
+        .send(&Method::Notify {
+            message: "persisted notification".to_string(),
+            auto_run: true,
+        })
+        .await?;
+    wait_for_run_end(&mut protocol_client).await?;
+    host.shutdown().await?;
+
+    let store = StandaloneWorkerStore::open(&state_dir)?;
+    let current = store.list(&cwd, StandaloneListScope::CurrentCwd, 100)?;
+    assert_eq!(current.len(), 1);
+    assert_eq!(current[0].worker_id, worker_id);
+    assert_eq!(current[0].status, StandaloneWorkerStatus::Stopped);
+    let other_cwd = temp.path().join("other");
+    std::fs::create_dir(&other_cwd)?;
+    assert!(
+        store
+            .list(&other_cwd, StandaloneListScope::CurrentCwd, 100)?
+            .is_empty()
+    );
+    assert_eq!(
+        store.list(&other_cwd, StandaloneListScope::All, 100)?.len(),
+        1
+    );
+
+    let second_client = ScriptedClient::new(vec![vec![
+        LlmEvent::text_block_start(0),
+        LlmEvent::text_delta(0, "second answer"),
+        LlmEvent::text_block_stop(0, Some(StopReason::EndTurn)),
+    ]]);
+    let second_inspection = second_client.clone();
+    let host =
+        StandaloneHost::restore_with_model_client(state_dir.clone(), worker_id, second_client)
+            .await?;
+    assert_eq!(
+        host.record().worker_name,
+        "display-name-is-not-session-identity"
+    );
+    assert_eq!(host.record().storage_key, format!("standalone-{worker_id}"));
+    let mut protocol_client = host.connect();
+    let snapshot = format!(
+        "{:?}",
+        protocol_client
+            .next_event()
+            .await
+            .expect("restored protocol stream")
+            .expect("restored snapshot")
+    );
+    assert!(snapshot.contains("first request"), "{snapshot}");
+    assert!(snapshot.contains("first answer"), "{snapshot}");
+    assert!(snapshot.contains("persisted task"), "{snapshot}");
+    assert!(snapshot.contains("persisted notification"), "{snapshot}");
+
+    protocol_client
+        .send(&Method::run_text("continue after restore"))
+        .await?;
+    wait_for_run_end(&mut protocol_client).await?;
+    let request = second_inspection
+        .requests()
+        .into_iter()
+        .next()
+        .expect("restored run request");
+    let projected = format!("{:?}", request.items);
+    assert!(projected.contains("first answer"), "{projected}");
+    assert!(projected.contains("persisted notification"), "{projected}");
+    assert!(projected.contains("persisted task"), "{projected}");
+    host.shutdown().await?;
+
+    store.delete(worker_id)?;
+    assert!(cwd.exists(), "deleting session state must not mutate cwd");
+    assert!(matches!(
+        store.load(worker_id),
+        Err(StandaloneStoreError::WorkerNotFound(_))
+    ));
+    Ok(())
+}
+
+#[tokio::test]
+async fn standalone_restore_rejects_concurrent_lease_and_missing_cwd() -> TestResult {
+    let temp = tempfile::tempdir()?;
+    let cwd = temp.path().join("project");
+    let moved = temp.path().join("moved-project");
+    let state_dir = temp.path().join("state");
+    std::fs::create_dir(&cwd)?;
+    let launch = StandaloneLaunchConfig::new(
+        &cwd,
+        &state_dir,
+        manifest::ProfileSelector::Default,
+        "standalone-lease-test",
+    )
+    .resolve()?;
+    let host =
+        StandaloneHost::start_with_model_client(launch, ScriptedClient::new(Vec::new())).await?;
+    let worker_id = host.worker_id();
+    let store = StandaloneWorkerStore::open(&state_dir)?;
+    assert!(matches!(
+        store.acquire_lease(worker_id, StaleLeasePolicy::Recover),
+        Err(StandaloneStoreError::WorkerLeased(id)) if id == worker_id
+    ));
+    let restore = StandaloneHost::restore_with_model_client(
+        state_dir.clone(),
+        worker_id,
+        ScriptedClient::new(Vec::new()),
+    )
+    .await;
+    assert!(matches!(restore, Err(StandaloneStartupError::WorkerActive)));
+    host.shutdown().await?;
+
+    std::fs::rename(&cwd, &moved)?;
+    let restore = StandaloneHost::restore_with_model_client(
+        state_dir,
+        worker_id,
+        ScriptedClient::new(Vec::new()),
+    )
+    .await;
+    assert!(matches!(
+        restore,
+        Err(StandaloneStartupError::WorkingDirectoryUnavailable)
+    ));
+    Ok(())
+}
+
+#[tokio::test]
+async fn standalone_restore_recovers_only_a_proven_stale_lease() -> TestResult {
+    let temp = tempfile::tempdir()?;
+    let state_dir = temp.path().join("state");
+    let mut launch = StandaloneLaunchConfig::new(
+        temp.path(),
+        &state_dir,
+        manifest::ProfileSelector::Default,
+        "standalone-stale-lease-test",
+    )
+    .resolve()?;
+    launch.profile.manifest.profile = Some(manifest::ProfileManifestSnapshot {
+        source: manifest::ProfileSource::Registry {
+            source: manifest::ProfileRegistrySource::User,
+            name: "user-standalone".to_string(),
+            path: None,
+            provenance: Some("user-config-revision-7".to_string()),
+        },
+        profile: Some(manifest::ProfileMetadata {
+            name: Some("User standalone".to_string()),
+            description: None,
+            format: None,
+        }),
+    });
+    let host =
+        StandaloneHost::start_with_model_client(launch, ScriptedClient::new(Vec::new())).await?;
+    let worker_id = host.worker_id();
+    host.shutdown().await?;
+    let store = StandaloneWorkerStore::open(&state_dir)?;
+    assert!(matches!(
+        store.load(worker_id)?.manifest.profile,
+        Some(manifest::ProfileManifestSnapshot {
+            source: manifest::ProfileSource::Registry {
+                source: manifest::ProfileRegistrySource::User,
+                ..
+            },
+            ..
+        })
+    ));
+    let worker_dir = state_dir.join(worker_id.to_string());
+    std::fs::write(
+        worker_dir.join("lease.json"),
+        serde_json::to_vec(&serde_json::json!({
+            "lease_id": uuid::Uuid::now_v7(),
+            "pid": u32::MAX,
+            "process_start_marker": 1,
+            "acquired_at_unix_ms": 1
+        }))?,
+    )?;
+
+    let host = StandaloneHost::restore_with_model_client(
+        state_dir,
+        worker_id,
+        ScriptedClient::new(Vec::new()),
+    )
+    .await?;
+    host.shutdown().await?;
+    Ok(())
+}
+
+#[tokio::test]
+async fn standalone_restore_rejects_lease_with_missing_start_marker() -> TestResult {
+    let temp = tempfile::tempdir()?;
+    let state_dir = temp.path().join("state");
+    let launch = StandaloneLaunchConfig::new(
+        temp.path(),
+        &state_dir,
+        manifest::ProfileSelector::Default,
+        "standalone-unknown-lease-test",
+    )
+    .resolve()?;
+    let host =
+        StandaloneHost::start_with_model_client(launch, ScriptedClient::new(Vec::new())).await?;
+    let worker_id = host.worker_id();
+    host.shutdown().await?;
+    let worker_dir = state_dir.join(worker_id.to_string());
+    std::fs::write(
+        worker_dir.join("lease.json"),
+        serde_json::to_vec(&serde_json::json!({
+            "lease_id": uuid::Uuid::now_v7(),
+            "pid": std::process::id(),
+            "acquired_at_unix_ms": 1
+        }))?,
+    )?;
+
+    let store = StandaloneWorkerStore::open(&state_dir)?;
+    assert!(matches!(
+        store.acquire_lease(worker_id, StaleLeasePolicy::Recover),
+        Err(StandaloneStoreError::LeaseLivenessUnknown(id)) if id == worker_id
+    ));
+    let restore = StandaloneHost::restore_with_model_client(
+        state_dir,
+        worker_id,
+        ScriptedClient::new(Vec::new()),
+    )
+    .await;
+    assert!(matches!(
+        restore,
+        Err(StandaloneStartupError::LeaseLivenessUnknown)
+    ));
+    Ok(())
+}
+
+#[tokio::test]
+async fn standalone_metadata_fails_closed_on_incomplete_or_newer_records() -> TestResult {
+    let temp = tempfile::tempdir()?;
+    let state_dir = temp.path().join("state");
+    let launch = StandaloneLaunchConfig::new(
+        temp.path(),
+        &state_dir,
+        manifest::ProfileSelector::Default,
+        "standalone-schema-test",
+    )
+    .resolve()?;
+    let host =
+        StandaloneHost::start_with_model_client(launch, ScriptedClient::new(Vec::new())).await?;
+    let worker_id = host.worker_id();
+    host.shutdown().await?;
+    let store = StandaloneWorkerStore::open(&state_dir)?;
+    let worker_dir = state_dir.join(worker_id.to_string());
+    std::fs::write(worker_dir.join("commit.pending"), b"interrupted\n")?;
+    assert!(matches!(
+        store.load(worker_id),
+        Err(StandaloneStoreError::IncompleteCommit(id)) if id == worker_id
+    ));
+    std::fs::remove_file(worker_dir.join("commit.pending"))?;
+    let record_path = worker_dir.join("record.json");
+    let mut record: serde_json::Value = serde_json::from_slice(&std::fs::read(&record_path)?)?;
+    record["schema_version"] = serde_json::json!(u32::MAX);
+    std::fs::write(&record_path, serde_json::to_vec_pretty(&record)?)?;
+    assert!(matches!(
+        store.load(worker_id),
+        Err(StandaloneStoreError::NewerSchema { id, .. }) if id == worker_id
+    ));
+    Ok(())
+}
+
+async fn wait_for_run_end(client: &mut Client<InProcessSocket>) -> TestResult {
+    tokio::time::timeout(Duration::from_secs(10), async {
+        loop {
+            if matches!(client.next_event().await, Ok(Some(Event::RunEnd { .. }))) {
+                break;
+            }
+        }
+    })
+    .await?;
+    Ok(())
+}
@@ -142,8 +142,8 @@ const INTAKE_READY_DESCRIPTION: &str = "Record a bounded intake summary and mark
 The backend applies the same target validation and lock as TicketMarkReady and commits the summary, \
 state_changed event, effective target, and planning -> ready transition atomically.";
 const QUEUE_DESCRIPTION: &str = "Queue a ready Ticket for Orchestrator routing through the typed \
-Ticket backend. The backend performs the gated ready -> queued transition, records queued_by/queued_at, \
-and rejects unresolved blocking relations.";
+Ticket backend. The backend rejects transitive planning dependencies and cycles, atomically queues the \
+requested Ticket plus every transitive ready dependency, and leaves queued or in-progress dependencies unchanged.";
 const WORKFLOW_STATE_DESCRIPTION: &str = "Transition Ticket `state` through the typed \
 Ticket backend with a bounded `state_changed` event. Treat `queued -> inprogress` \
 as the implementation acceptance step: implementation side effects should happen only after that \
@@ -316,7 +316,11 @@ impl TicketBackend for TicketToolBackend {
        self.backend.mark_ready(id, request)
    }

-    fn queue_ready(&self, id: TicketIdOrSlug, queued_by: &str) -> TicketResult<()> {
+    fn queue_ready(
+        &self,
+        id: TicketIdOrSlug,
+        queued_by: &str,
+    ) -> TicketResult<crate::TicketQueueOutcome> {
        self.backend.queue_ready(id, queued_by)
    }

@@ -398,15 +402,15 @@ struct TicketCreateParams {
    queued_at: Option<String>,
    /// Optional target Workspace repository id.
    #[serde(default)]
-    repository_id: Option<String>,
-    /// Optional target Git ref selector. Requires `repository_id`.
+    repository_key: Option<String>,
+    /// Optional target Git ref selector. Requires `repository_key`.
    #[serde(default)]
    ref_selector: Option<String>,
 }

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketEditItemParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Optional replacement title.
    #[serde(default)]
@@ -535,7 +539,7 @@ impl QueryTicketParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct ShowTicketParams {
-    /// Ticket id. Exactly one of `id` or `query` must be provided.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility. Exactly one of `id` or `query` must be provided.
    #[serde(default)]
    id: Option<String>,
    /// Exact ticket id query. Exactly one of `id` or `query` must be provided.
@@ -554,7 +558,7 @@ struct ShowTicketParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketThreadEventParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Markdown event body.
    body: String,
@@ -562,7 +566,7 @@ struct TicketThreadEventParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketMarkReadyParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Optional reason attached to the state_changed event.
    #[serde(default)]
@@ -571,7 +575,7 @@ struct TicketMarkReadyParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketIntakeReadyParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Concise bounded intake summary appended before the ready transition.
    intake_summary: String,
@@ -582,13 +586,13 @@ struct TicketIntakeReadyParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketQueueParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
 }

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketWorkflowStateParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Expected current state. The backend rejects stale transitions.
    from: TicketWorkflowStateParam,
@@ -602,7 +606,7 @@ struct TicketWorkflowStateParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketCloseParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
    /// Markdown resolution written to resolution.md and thread.md.
    resolution: String,
@@ -610,7 +614,7 @@ struct TicketCloseParams {

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TicketDependencyCheckParams {
-    /// Ticket id.
+    /// Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    ticket: String,
 }

@@ -642,7 +646,7 @@ struct TicketRelationRecordParams {
    ticket: String,
    /// Forward relation kind: depends_on, blocks, related, supersedes, or duplicate_of.
    kind: TicketRelationKindParam,
-    /// Target canonical Ticket id. Title/slug words are not accepted as relation authority.
+    /// Target Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    target: String,
    /// Optional bounded rationale/note.
    #[serde(default)]
@@ -655,7 +659,7 @@ struct TicketRelationRemoveParams {
    ticket: String,
    /// Forward relation kind to remove.
    kind: TicketRelationKindParam,
-    /// Target canonical Ticket id.
+    /// Target Ticket reference. Prefer `T-*`; canonical internal ids remain accepted for compatibility.
    target: String,
 }

@@ -940,7 +944,7 @@ impl Tool for TicketCreateTool {
        input.workflow_state = params.state.map(TicketWorkflowStateParam::into_state);
        input.queued_by = None;
        input.queued_at = params.queued_at;
-        input.repository_id = params.repository_id;
+        input.repository_id = params.repository_key;
        input.ref_selector = params.ref_selector;

        let created = self
@@ -1169,7 +1173,7 @@ impl Tool for TicketMarkReadyTool {
            json!({
                "ticket": ticket.meta.id,
                "state": ticket.meta.workflow_state.as_str(),
-                "repository_id": ticket.meta.repository_id,
+                "repository_key": ticket.meta.repository_id,
                "ref_selector": ticket.meta.ref_selector,
                "ok": true
            }),
@@ -1202,7 +1206,7 @@ impl Tool for TicketIntakeReadyTool {
            json!({
                "ticket": ticket.meta.id,
                "state": ticket.meta.workflow_state.as_str(),
-                "repository_id": ticket.meta.repository_id,
+                "repository_key": ticket.meta.repository_id,
                "ref_selector": ticket.meta.ref_selector,
                "ok": true
            }),
@@ -1219,12 +1223,29 @@ impl Tool for TicketQueueTool {
    ) -> Result<ToolOutput, ToolError> {
        let params: TicketQueueParams = parse_input("TicketQueue", input_json)?;
        let queued_by = default_author();
-        self.backend
+        let mut outcome = self
+            .backend
            .queue_ready(TicketIdOrSlug::Query(params.ticket.clone()), &queued_by)
            .map_err(|error| backend_error("TicketQueue", error))?;
+        outcome.requested_ticket =
+            model_ticket_reference(&self.backend, &outcome.requested_ticket, "TicketQueue")?;
+        outcome.queued_tickets = outcome
+            .queued_tickets
+            .into_iter()
+            .map(|ticket| model_ticket_reference(&self.backend, &ticket, "TicketQueue"))
+            .collect::<Result<Vec<_>, _>>()?;
        Ok(json_output(
-            format!("Queued ticket {} for Orchestrator", params.ticket),
-            json!({ "ticket": params.ticket, "state": "queued", "queued_by": queued_by, "ok": true }),
+            format!(
+                "Queued {} ticket(s) for Orchestrator",
+                outcome.queued_tickets.len()
+            ),
+            json!({
+                "ticket": outcome.requested_ticket,
+                "queued_tickets": outcome.queued_tickets,
+                "state": "queued",
+                "queued_by": queued_by,
+                "ok": true
+            }),
        ))
    }
 }
@@ -1250,15 +1271,17 @@ impl Tool for TicketWorkflowStateTool {
        self.backend
            .set_workflow_state(TicketIdOrSlug::Query(params.ticket.clone()), change)
            .map_err(|error| backend_error("TicketWorkflowState", error))?;
+        let ticket_ref =
+            model_ticket_reference(&self.backend, &params.ticket, "TicketWorkflowState")?;
        Ok(json_output(
            format!(
                "Transitioned ticket {} state {} -> {}",
-                params.ticket,
+                ticket_ref,
                from.as_str(),
                to.as_str()
            ),
            json!({
-                "ticket": params.ticket,
+                "ticket": ticket_ref,
                "from": from.as_str(),
                "to": to.as_str(),
                "state": to.as_str(),
@@ -1282,9 +1305,10 @@ impl Tool for TicketCloseTool {
                MarkdownText::new(params.resolution),
            )
            .map_err(|error| backend_error("TicketClose", error))?;
+        let ticket_ref = model_ticket_reference(&self.backend, &params.ticket, "TicketClose")?;
        Ok(json_output(
-            format!("Closed ticket {}", params.ticket),
-            json!({ "ticket": params.ticket, "state": "closed", "ok": true }),
+            format!("Closed ticket {ticket_ref}"),
+            json!({ "ticket": ticket_ref, "state": "closed", "ok": true }),
        ))
    }
 }
@@ -1511,6 +1535,29 @@ impl Tool for TicketDependencyCheckTool {
    }
 }

+fn model_ticket_reference(
+    backend: &TicketToolBackend,
+    reference: &str,
+    tool_name: &str,
+) -> Result<String, ToolError> {
+    let ticket = backend
+        .show(TicketIdOrSlug::Id(reference.to_string()))
+        .map_err(|error| backend_error(tool_name, error))?;
+    match ticket.meta.resource_key {
+        Some(resource_key) if is_canonical_ticket_resource_key(&resource_key) => Ok(resource_key),
+        Some(_) => Err(ToolError::ExecutionFailed(format!(
+            "{tool_name} failed: required Ticket key is unavailable"
+        ))),
+        None => Ok(ticket.meta.id),
+    }
+}
+
+fn is_canonical_ticket_resource_key(resource_key: &str) -> bool {
+    resource_key.strip_prefix("T-").is_some_and(|sequence| {
+        !sequence.is_empty() && sequence.bytes().all(|byte| byte.is_ascii_digit())
+    })
+}
+
 fn parse_input<T: for<'de> Deserialize<'de>>(tool: &str, input_json: &str) -> Result<T, ToolError> {
    serde_json::from_str(input_json)
        .map_err(|error| ToolError::InvalidArgument(format!("invalid {tool} input: {error}")))
@@ -1893,11 +1940,11 @@ mod tests {
        fn resolve_target(
            &self,
            _workspace_id: &str,
-            repository_id: Option<&str>,
+            repository_key: Option<&str>,
            ref_selector: Option<&str>,
        ) -> crate::Result<crate::ResolvedTicketTarget> {
            Ok(crate::ResolvedTicketTarget {
-                repository_id: repository_id.unwrap_or("main").to_owned(),
+                repository_id: repository_key.unwrap_or("main").to_owned(),
                ref_selector: ref_selector.unwrap_or("develop").to_owned(),
            })
        }
@@ -1908,6 +1955,12 @@ mod tests {
            .with_target_authority(Arc::new(TestTargetAuthority))
    }

+    fn sqlite_backend(temp: &TempDir) -> crate::SqliteTicketBackend {
+        crate::SqliteTicketBackend::open(temp.path().join("tickets.db"), "workspace")
+            .unwrap()
+            .with_target_authority(Arc::new(TestTargetAuthority))
+    }
+
    fn tool(definition: ToolDefinition) -> Arc<dyn Tool> {
        let (_, tool) = definition();
        tool
@@ -2535,6 +2588,101 @@ mod tests {
        );
    }

+    #[tokio::test]
+    async fn queue_workflow_and_close_project_internal_inputs_to_ticket_keys() {
+        let temp = TempDir::new().unwrap();
+        let inner = sqlite_backend(&temp);
+        let mut dependency_input = NewTicket::new("Dependency");
+        dependency_input.repository_id = Some("main".to_string());
+        let dependency = inner.create(dependency_input).unwrap();
+        let mut target_input = NewTicket::new("Target");
+        target_input.repository_id = Some("main".to_string());
+        let target = inner.create(target_input).unwrap();
+        inner
+            .add_ticket_relation(
+                TicketIdOrSlug::Id(target.id.clone()),
+                NewTicketRelation {
+                    kind: TicketRelationKind::DependsOn,
+                    target: dependency.id.clone(),
+                    note: None,
+                    author: None,
+                },
+            )
+            .unwrap();
+        for id in [&dependency.id, &target.id] {
+            inner
+                .mark_ready(
+                    TicketIdOrSlug::Id(id.clone()),
+                    TicketMarkReady {
+                        operation_key: format!("ready-{id}"),
+                        reason: None,
+                        author: None,
+                        intake_summary: None,
+                    },
+                )
+                .unwrap();
+        }
+        let target_key = target.resource_key.clone().unwrap();
+        let dependency_key = dependency.resource_key.clone().unwrap();
+        let backend = inner;
+        let queue = tool_by_name(TicketToolBackend::new(backend.clone()), "TicketQueue");
+        let workflow = tool_by_name(
+            TicketToolBackend::new(backend.clone()),
+            "TicketWorkflowState",
+        );
+        let close = tool_by_name(TicketToolBackend::new(backend), "TicketClose");
+
+        let queued = queue
+            .execute(
+                &json!({"ticket": target.id.clone()}).to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+        assert!(queued.summary.contains("2 ticket(s)"));
+        let queued_content = queued.content.unwrap();
+        assert!(queued_content.contains(&target_key));
+        assert!(queued_content.contains(&dependency_key));
+        assert!(!queued_content.contains(&target.id));
+        assert!(!queued_content.contains(&dependency.id));
+
+        for (from, to) in [("queued", "inprogress"), ("inprogress", "done")] {
+            let transitioned = workflow
+                .execute(
+                    &json!({
+                        "ticket": target.id.clone(),
+                        "from": from,
+                        "to": to,
+                        "reason": "test_transition",
+                        "body": "transitioned",
+                        "author": "tester"
+                    })
+                    .to_string(),
+                    Default::default(),
+                )
+                .await
+                .unwrap();
+            assert!(transitioned.summary.contains(&target_key));
+            assert!(!transitioned.summary.contains(&target.id));
+            let content = transitioned.content.unwrap();
+            assert!(content.contains(&target_key));
+            assert!(!content.contains(&target.id));
+        }
+
+        let closed = close
+            .execute(
+                &json!({"ticket": target.id.clone(), "resolution": "Done"}).to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+        assert!(closed.summary.contains(&target_key));
+        assert!(!closed.summary.contains(&target.id));
+        let content = closed.content.unwrap();
+        assert!(content.contains(&target_key));
+        assert!(!content.contains(&target.id));
+    }
+
    #[tokio::test]
    async fn ticket_workflow_tools_mark_ready_and_transition_state() {
        let temp = TempDir::new().unwrap();
@@ -1,5 +1,6 @@
+use std::collections::{HashMap, HashSet};
 use std::path::PathBuf;
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};

 use agen::tool::{Tool, ToolDefinition, ToolError, ToolMeta, ToolOutput};
 use async_trait::async_trait;
@@ -20,21 +21,66 @@ struct BashParams {

 pub(crate) struct BashTool {
    session: WorkdirSessionHandle,
+    output_dir: PathBuf,
+    state: Arc<Mutex<BashExecutionState>>,
+}
+
+#[derive(Clone)]
+struct ActiveCommand {
+    call_id: String,
+    execution_nonce: u64,
+    handle: CommandHandle,
+}
+
+#[derive(Default)]
+struct BashExecutionState {
+    active: HashMap<String, ActiveCommand>,
+    cancellation_requested: HashSet<String>,
+    legacy_cancellation_requested: HashSet<String>,
+    next_execution_nonce: u64,
 }

 struct CommandGuard {
    session: WorkdirSessionHandle,
+    state: Arc<Mutex<BashExecutionState>>,
+    execution_id: String,
+    execution_nonce: u64,
    handle: Option<CommandHandle>,
 }

 impl Drop for CommandGuard {
    fn drop(&mut self) {
-        if let Some(handle) = self.handle.take() {
+        let Some(handle) = self.handle.take() else {
+            return;
+        };
        let workdir = self.session.clone();
+        let state = Arc::clone(&self.state);
+        let execution_id = self.execution_id.clone();
+        let execution_nonce = self.execution_nonce;
+        // A dropped provider future is not terminal confirmation. Keep the live
+        // execution registered until cleanup has both requested cancellation and
+        // observed terminal command output, so cancellation/session teardown
+        // cannot race with an apparently empty registry.
        tokio::spawn(async move {
-                let _ = workdir.cancel_command(handle).await;
-            });
+            let _ = workdir.cancel_command(handle.clone()).await;
+            let _ = workdir
+                .command_output(CommandOutputRequest {
+                    handle,
+                    cursor: 0,
+                    limit: INLINE_BYTE_BUDGET,
+                    wait: true,
+                })
+                .await;
+            let mut state = state.lock().unwrap();
+            if state
+                .active
+                .get(&execution_id)
+                .is_some_and(|active| active.execution_nonce == execution_nonce)
+            {
+                state.active.remove(&execution_id);
+                state.cancellation_requested.remove(&execution_id);
            }
+        });
    }
 }

@@ -52,20 +98,51 @@ impl Tool for BashTool {
            .unwrap_or(DEFAULT_TIMEOUT_SECS)
            .clamp(1, MAX_TIMEOUT_SECS);
        let cmd_summary = truncate_for_summary(&params.command);
+        let execution_id = ctx.execution_id();
+        let call_id = ctx.call_id;
+        let execution_nonce = {
+            let mut state = self.state.lock().unwrap();
+            state.next_execution_nonce = state.next_execution_nonce.wrapping_add(1);
+            state.next_execution_nonce
+        };
+        let mut guard = CommandGuard {
+            session: self.session.clone(),
+            state: self.state.clone(),
+            execution_id: execution_id.clone(),
+            execution_nonce,
+            handle: None,
+        };
        let handle = self
            .session
            .start_command(CommandRequest {
                command: params.command,
                timeout_secs,
                output_limit: INLINE_BYTE_BUDGET,
-                tool_call_id: Some(ctx.call_id),
+                spill_dir: Some(self.output_dir.clone()),
+                tool_call_id: Some(call_id.clone()),
            })
            .await
            .map_err(crate::ToolsError::from)?;
-        let mut guard = CommandGuard {
-            session: self.session.clone(),
-            handle: Some(handle.clone()),
+        let cancel_after_start = {
+            let mut state = self.state.lock().unwrap();
+            state.active.insert(
+                execution_id.clone(),
+                ActiveCommand {
+                    call_id: call_id.clone(),
+                    execution_nonce,
+                    handle: handle.clone(),
+                },
+            );
+            state.cancellation_requested.contains(&execution_id)
+                || state.legacy_cancellation_requested.contains(&call_id)
        };
+        guard.handle = Some(handle.clone());
+        if cancel_after_start {
+            self.session
+                .cancel_command(handle.clone())
+                .await
+                .map_err(crate::ToolsError::from)?;
+        }
        let output = self
            .session
            .command_output(CommandOutputRequest {
@@ -76,9 +153,27 @@ impl Tool for BashTool {
            })
            .await
            .map_err(crate::ToolsError::from)?;
+        let cancellation_requested = {
+            let mut state = self.state.lock().unwrap();
+            let owns_registration = state
+                .active
+                .get(&execution_id)
+                .is_some_and(|active| active.execution_nonce == execution_nonce);
+            let exact = if owns_registration {
+                state.active.remove(&execution_id);
+                state.cancellation_requested.remove(&execution_id)
+            } else {
+                false
+            };
+            let legacy = state.legacy_cancellation_requested.remove(&call_id);
+            exact || legacy
+        };
        guard.handle = None;

-        let summary = if output.timed_out {
+        let timed_out = output.timed_out;
+        let summary = if cancellation_requested {
+            format!("$ {cmd_summary} (cancelled)")
+        } else if output.timed_out {
            format!("$ {cmd_summary} (timed out after {timeout_secs}s)")
        } else {
            match output.exit_code {
@@ -90,18 +185,74 @@ impl Tool for BashTool {
        let content = if output.content.is_empty() {
            None
        } else if output.truncated {
-            Some(format!(
-                "[showing bounded WorkdirSession command output; additional output was truncated]\n{}",
-                output.content
-            ))
+            let notice = match output.output_path {
+                Some(path) => format!(
+                    "[showing bounded WorkdirSession command output; full output saved to {}]",
+                    path.display()
+                ),
+                None => "[showing bounded WorkdirSession command output; additional output was truncated]"
+                    .to_owned(),
+            };
+            Some(format!("{notice}\n{}", output.content))
        } else {
            Some(output.content)
        };
-        Ok(ToolOutput {
+        let output = ToolOutput {
            summary,
            content,
            attachments: Vec::new(),
-        })
+        };
+        if cancellation_requested {
+            Err(ToolError::Cancelled(output))
+        } else if timed_out {
+            Err(ToolError::Interrupted(output))
+        } else {
+            Ok(output)
+        }
+    }
+
+    async fn cancel(&self, call_id: &str) -> Result<(), ToolError> {
+        let handles = {
+            let mut state = self.state.lock().unwrap();
+            state
+                .legacy_cancellation_requested
+                .insert(call_id.to_string());
+            state
+                .active
+                .values()
+                .filter(|active| active.call_id == call_id)
+                .map(|active| active.handle.clone())
+                .collect::<Vec<_>>()
+        };
+        for handle in handles {
+            self.session
+                .cancel_command(handle)
+                .await
+                .map_err(crate::ToolsError::from)?;
+        }
+        Ok(())
+    }
+
+    async fn cancel_execution(
+        &self,
+        ctx: &agen::tool::ToolExecutionContext,
+    ) -> Result<(), ToolError> {
+        let execution_id = ctx.execution_id();
+        let handle = {
+            let mut state = self.state.lock().unwrap();
+            state.cancellation_requested.insert(execution_id.clone());
+            state
+                .active
+                .get(&execution_id)
+                .map(|active| active.handle.clone())
+        };
+        if let Some(handle) = handle {
+            self.session
+                .cancel_command(handle)
+                .await
+                .map_err(crate::ToolsError::from)?;
+        }
+        Ok(())
    }
 }

@@ -115,15 +266,137 @@ fn truncate_for_summary(command: &str) -> String {
    summary
 }

-pub fn bash_tool(session: WorkdirSessionHandle, _output_dir: PathBuf) -> ToolDefinition {
+pub fn bash_tool(session: WorkdirSessionHandle, output_dir: PathBuf) -> ToolDefinition {
    Arc::new(move || {
        let schema = schemars::schema_for!(BashParams);
        let meta = ToolMeta::new("Bash")
-            .description("Execute a shell command in the bound Workdir. Process start, bounded output, timeout and cancellation are owned by the WorkdirSession provider. This is not a sandbox.")
+            .description("Execute a shell command in the bound Workdir. Process start, bounded inline output, full-output spill, timeout and cancellation are owned by the WorkdirSession provider. This is not a sandbox.")
            .input_schema(serde_json::to_value(schema).expect("Bash schema serialization"));
        let tool: Arc<dyn Tool> = Arc::new(BashTool {
            session: session.clone(),
+            output_dir: output_dir.clone(),
+            state: Arc::new(Mutex::new(BashExecutionState::default())),
        });
        (meta, tool)
    })
 }
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use manifest::{Permission, Scope, ScopeConfig, ScopeRule};
+    use tempfile::TempDir;
+    use workdir::{LocalWorkdirSession, WorkdirSessionHandle};
+
+    use super::bash_tool;
+    use crate::{grep::grep_tool, read::read_tool, tracker::Tracker};
+
+    fn session_with_output_scope(root: &TempDir, output: &TempDir) -> WorkdirSessionHandle {
+        let scope = Scope::from_config(&ScopeConfig {
+            allow: vec![
+                ScopeRule {
+                    target: root.path().to_path_buf(),
+                    permission: Permission::Write,
+                    recursive: true,
+                },
+                ScopeRule {
+                    target: output.path().to_path_buf(),
+                    permission: Permission::Read,
+                    recursive: true,
+                },
+            ],
+            deny: Vec::new(),
+        })
+        .unwrap();
+        Arc::new(LocalWorkdirSession::new(scope, root.path().to_path_buf()))
+    }
+
+    #[tokio::test]
+    async fn long_output_is_spilled_and_available_to_read_and_grep() {
+        let root = TempDir::new().unwrap();
+        let output = TempDir::new().unwrap();
+        let session = session_with_output_scope(&root, &output);
+        let (_, bash) = bash_tool(session.clone(), output.path().to_path_buf())();
+        let command = "i=0; while [ $i -lt 2000 ]; do printf 'line-%04d\\n' \"$i\"; i=$((i+1)); done; printf 'FINAL-NEEDLE\\n'";
+        let result = bash
+            .execute(
+                &serde_json::json!({ "command": command }).to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+        let rendered = result.content.expect("bounded Bash output");
+        let artifact = std::fs::read_dir(output.path())
+            .unwrap()
+            .next()
+            .expect("artifact entry")
+            .unwrap()
+            .path();
+
+        assert!(rendered.contains("full output saved to"));
+        assert!(rendered.contains(&artifact.display().to_string()));
+        let retained = std::fs::read_to_string(&artifact).unwrap();
+        assert!(retained.starts_with("line-0000\n"));
+        assert!(retained.ends_with("FINAL-NEEDLE\n"));
+        assert_eq!(retained.lines().count(), 2001);
+
+        let (_, read) = read_tool(session.clone(), Tracker::new())();
+        let read_result = read
+            .execute(
+                &serde_json::json!({
+                    "file_path": artifact,
+                    "offset": 2000,
+                    "limit": 1,
+                })
+                .to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+        assert!(
+            read_result
+                .content
+                .expect("Read content")
+                .contains("FINAL-NEEDLE")
+        );
+
+        let (_, grep) = grep_tool(session)();
+        let grep_result = grep
+            .execute(
+                &serde_json::json!({
+                    "pattern": "FINAL-NEEDLE",
+                    "path": artifact,
+                    "output_mode": "content",
+                })
+                .to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+        let grep_content = grep_result.content.expect("Grep content");
+        assert!(
+            grep_content.contains("FINAL-NEEDLE"),
+            "unexpected Grep content: {grep_content:?}"
+        );
+    }
+
+    #[tokio::test]
+    async fn short_output_does_not_leave_a_spill_artifact() {
+        let root = TempDir::new().unwrap();
+        let output = TempDir::new().unwrap();
+        let session = session_with_output_scope(&root, &output);
+        let (_, bash) = bash_tool(session, output.path().to_path_buf())();
+
+        let result = bash
+            .execute(
+                &serde_json::json!({ "command": "printf short" }).to_string(),
+                Default::default(),
+            )
+            .await
+            .unwrap();
+
+        assert_eq!(result.content.as_deref(), Some("short"));
+        assert_eq!(std::fs::read_dir(output.path()).unwrap().count(), 0);
+    }
+}
@@ -42,6 +42,7 @@ impl From<ToolsError> for ToolError {
                workdir::WorkdirError::NotFound(_)
                | workdir::WorkdirError::Io { .. }
                | workdir::WorkdirError::Unavailable(_)
+                | workdir::WorkdirError::OperationFailed
                | workdir::WorkdirError::Transport(_),
            ) => ToolError::ExecutionFailed(err.to_string()),
            ToolsError::FileSystem(_)
@@ -22,7 +22,7 @@ enum OutputMode {
 #[derive(Debug, Deserialize, JsonSchema)]
 struct GrepParams {
    pattern: String,
-    /// Logical Workdir-relative path to search. Defaults to the Workdir root.
+    /// Workdir-relative path, or an absolute path covered by readable scope. Defaults to the Workdir root.
    #[serde(default)]
    path: Option<String>,
    #[serde(default)]
@@ -61,7 +61,7 @@ impl Tool for GrepTool {
        let params: GrepParams = serde_json::from_str(input_json)
            .map_err(|error| ToolError::InvalidArgument(format!("invalid Grep input: {error}")))?;
        let path = match params.path {
-            Some(path) => WorkdirPath::new(&path).map_err(ToolsError::from)?,
+            Some(path) => WorkdirPath::new_scoped(&path).map_err(ToolsError::from)?,
            None => WorkdirPath::root(),
        };
        let mode = match params.output_mode.unwrap_or_default() {
@@ -129,7 +129,7 @@ pub fn grep_tool(session: WorkdirSessionHandle) -> ToolDefinition {
    Arc::new(move || {
        let schema = schemars::schema_for!(GrepParams);
        let meta = ToolMeta::new("Grep")
-            .description("Search Workdir file contents with a regex. Glob/Grep traversal executes inside the WorkdirSession provider. Results are bounded and Workdir-relative.")
+            .description("Search a Workdir file or directory with a regex. Content results group lines by file; `>` marks matching lines and unmarked lines are context. Directory traversal executes inside the WorkdirSession provider. Results are bounded and Workdir-relative.")
            .input_schema(serde_json::to_value(schema).expect("Grep schema serialization"));
        let tool: Arc<dyn Tool> = Arc::new(GrepTool {
            session: session.clone(),
@@ -13,14 +13,14 @@ use workdir::{ReadRequest, WorkdirPath, WorkdirSessionHandle};
 const DESCRIPTION: &str = "Read a text file from the local filesystem. \
 Supports offset/limit for large files. Returns line-numbered output (1-based). \
 Directories cannot be read. The file must be read before Write or Edit can \
-modify it. Paths are relative to the bound Workdir.";
+modify it. Paths are Workdir-relative unless an absolute path is explicitly readable.";

 const DEFAULT_LIMIT: usize = 2000;
 const PROVIDER_BYTE_LIMIT: usize = 256 * 1024;

 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 pub(crate) struct ReadParams {
-    /// Logical path relative to the bound Workdir root.
+    /// Workdir-relative path, or an absolute path covered by readable scope.
    pub file_path: String,
    /// 0-based line offset from the start. Defaults to 0.
    #[serde(default)]
@@ -47,7 +47,7 @@ impl Tool for ReadTool {
        let offset = params.offset.unwrap_or(0);
        let limit = params.limit.unwrap_or(DEFAULT_LIMIT).max(1);

-        let path = WorkdirPath::new(&params.file_path).map_err(ToolsError::from)?;
+        let path = WorkdirPath::new_scoped(&params.file_path).map_err(ToolsError::from)?;
        tracing::debug!(path = %path, offset, limit, "Read");

        let result = self
@@ -131,10 +131,11 @@ async fn symlink_to_outside_scope_is_rejected_for_write() {
    assert!(
        msg.contains("outside allowed read scope")
            || msg.contains("outside allowed write scope")
+            || msg.contains("outside allowed scope")
            || msg.contains("has not been read"),
        "symlink escape not rejected: {msg}"
    );
-    if !msg.contains("has not been read") {
+    if msg.contains("outside allowed read scope") || msg.contains("outside allowed write scope") {
        assert!(
            msg.contains("add the symlink target"),
            "symlink escape diagnostic should include remediation: {msg}"
@@ -223,22 +224,29 @@ async fn very_long_single_line() {
 }

 #[tokio::test]
-async fn absolute_path_is_rejected() {
-    let (dir, _spill, reg) = setup();
+async fn absolute_path_requires_matching_read_scope() {
+    let (_dir, _spill, reg) = setup();
+    let outside = tempfile::tempdir().unwrap();
+    let outside_file = outside.path().join("outside.txt");
+    std::fs::write(&outside_file, "secret").unwrap();
    let read = reg.get("Read");
    let err = read
        .execute(
-            &json!({ "file_path": dir.path().join("outside.txt") }).to_string(),
+            &json!({ "file_path": outside_file }).to_string(),
            Default::default(),
        )
        .await
        .unwrap_err();
-    assert!(format!("{err}").contains("invalid Workdir path"));
+    let msg = format!("{err}");
+    assert!(
+        msg.contains("outside allowed scope"),
+        "absolute path escaped readable scope: {msg}"
+    );
 }

 #[tokio::test]
 async fn directory_target_is_rejected_for_read() {
-    let (dir, _spill, reg) = setup();
+    let (_dir, _spill, reg) = setup();
    let read = reg.get("Read");
    let err = read
        .execute(&json!({ "file_path": "." }).to_string(), Default::default())
@@ -7,7 +7,10 @@
 use std::path::Path;
 use std::sync::Arc;

-use agen::tool::{Tool, ToolDefinition, ToolMeta};
+use agen::tool::{
+    Tool, ToolDefinition, ToolError, ToolExecutionContext, ToolExecutionHandle,
+    ToolExecutionTerminal, ToolMeta,
+};
 use manifest::{Permission, Scope, ScopeConfig, ScopeRule};
 use serde_json::json;
 use tempfile::TempDir;
@@ -191,7 +194,7 @@ async fn write_then_grep_finds_content() {

 #[tokio::test]
 async fn glob_finds_written_files() {
-    let (dir, _spill, reg) = setup();
+    let (_dir, _spill, reg) = setup();
    let write = reg.get("Write");
    let glob = reg.get("Glob");

@@ -229,7 +232,10 @@ async fn absolute_path_is_rejected() {
    .await;
    // Absolute paths are rejected at the logical WorkdirSession boundary.
    let msg = format!("{err}");
-    assert!(msg.contains("invalid Workdir path"), "unexpected: {msg}");
+    assert!(
+        msg.contains("invalid logical filesystem path"),
+        "unexpected: {msg}"
+    );
 }

 #[tokio::test]
@@ -340,7 +346,7 @@ async fn tracker_recent_files_tracks_read_write_edit() {
    ));

    let a = dir.path().join("a.txt");
-    let b = dir.path().join("b.txt");
+    let _b = dir.path().join("b.txt");
    std::fs::write(&a, "one\n").unwrap();

    // Read `a` — should appear in recency.
@@ -388,14 +394,100 @@ async fn bash_inherits_workdir_cwd() {
 }

 #[tokio::test]
-async fn bash_provider_output_does_not_expose_internal_paths() {
+async fn bash_provider_output_exposes_readable_retained_path() {
    let (_dir, spill, reg) = setup();
    let bash = reg.get("Bash");
    let out = call(&bash, json!({ "command": "printf 'x%.0s' {1..20480}" })).await;
    let body = out.content.unwrap();
    assert!(body.contains("bounded WorkdirSession command output"));
-    assert!(!body.contains(spill.path().to_str().unwrap()));
-    assert_eq!(std::fs::read_dir(spill.path()).unwrap().count(), 0);
+    assert!(body.contains("full output saved to"));
+    assert!(body.contains(spill.path().to_str().unwrap()));
+    let artifact = std::fs::read_dir(spill.path())
+        .unwrap()
+        .next()
+        .expect("retained output")
+        .unwrap()
+        .path();
+    assert_eq!(std::fs::metadata(artifact).unwrap().len(), 20_480);
+}
+
+#[tokio::test]
+async fn bash_cancellation_returns_bounded_progress_as_terminal_output() {
+    let (dir, _spill, reg) = setup();
+    let marker = dir.path().join("must-not-run-after-cancel");
+    let command = format!(
+        "printf 'before\\n'; printf 'err-before\\n' >&2; sleep 1; touch {}; printf 'after\\n'",
+        marker.display()
+    );
+    let input = serde_json::to_string(&json!({ "command": command })).unwrap();
+    let context = ToolExecutionContext::new("call-heavy", "attempt-heavy", 0);
+    let bash = reg.get("Bash");
+    let executing = bash.clone();
+    let execution_context = context.clone();
+    let execution = tokio::spawn(async move { executing.execute(&input, execution_context).await });
+
+    tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+    bash.cancel_execution(&context)
+        .await
+        .expect("signal exact execution cancellation");
+    let error = tokio::time::timeout(std::time::Duration::from_secs(2), execution)
+        .await
+        .expect("cancelled Bash should terminate inside the Engine grace budget")
+        .expect("Bash task join");
+
+    let ToolError::Cancelled(output) = error.expect_err("cancelled command is non-success") else {
+        panic!("expected typed cancellation result");
+    };
+    let content = output.content.expect("bounded progress output");
+    assert!(
+        content.contains("before"),
+        "missing pre-cancel stdout: {content}"
+    );
+    assert!(
+        content.contains("err-before"),
+        "missing pre-cancel stderr: {content}"
+    );
+    assert!(
+        !content.contains("after"),
+        "post-cancel output leaked: {content}"
+    );
+    assert!(content.len() <= 16 * 1024, "output must remain bounded");
+
+    tokio::time::sleep(std::time::Duration::from_millis(1_100)).await;
+    assert!(
+        !marker.exists(),
+        "the cancelled command continued executing after terminal confirmation"
+    );
+}
+
+#[tokio::test]
+async fn bash_force_close_cleanup_stops_command_and_keeps_session_reusable() {
+    let (dir, _spill, reg) = setup();
+    let marker = dir.path().join("must-not-survive-force-close");
+    let command = format!("sleep 1; touch {}", marker.display());
+    let input = serde_json::to_string(&json!({ "command": command })).unwrap();
+    let bash = reg.get("Bash");
+    let context = ToolExecutionContext::new("call-force", "attempt-force", 0);
+    let (handle, terminal) = ToolExecutionHandle::start(bash.clone(), input, context);
+
+    tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+    handle.force_close();
+    assert!(matches!(
+        terminal.await,
+        ToolExecutionTerminal::OutcomeUnknown
+    ));
+
+    tokio::time::sleep(std::time::Duration::from_millis(1_100)).await;
+    assert!(
+        !marker.exists(),
+        "CommandGuard cleanup allowed a force-closed command to continue"
+    );
+
+    let output = bash
+        .execute(r#"{"command":"printf 'reused'"}"#, Default::default())
+        .await
+        .expect("workdir session remains reusable after cleanup");
+    assert_eq!(output.content.as_deref(), Some("reused"));
 }

 // Sanity: unused Path import guard
@@ -10,11 +10,13 @@ e2e-test = []

 [dependencies]
 client = { workspace = true }
+standalone = { workspace = true }
+thiserror.workspace = true
 protocol = { workspace = true }
 ratatui = { version = "0.30.0", features = ["scrolling-regions"] }
 base64 = "0.22.1"
 crossterm = "0.28"
-tokio = { workspace = true, features = ["rt-multi-thread", "macros", "net", "io-util", "sync", "time", "process"] }
+tokio = { workspace = true, features = ["rt-multi-thread", "macros", "sync", "time"] }
 serde_json = { workspace = true }
 unicode-width = "0.2.2"
 uuid = { workspace = true }
@@ -22,12 +24,11 @@ toml = { workspace = true }
 manifest = { workspace = true }
 secrets = { workspace = true }
 session-store = { workspace = true }
-fs4 = { workspace = true }
 ticket = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
-worker = { path = "../worker" }
 pulldown-cmark = { version = "0.13.3", default-features = false }
 agen.workspace = true

 [dev-dependencies]
+async-trait.workspace = true
 tempfile = { workspace = true }
@@ -249,6 +249,9 @@ pub struct App {
    pub running: bool,
    /// True while the Worker is in `WorkerStatus::Paused`.
    pub paused: bool,
+    /// Local observation time for the current run. Used only for live UI
+    /// elapsed time and spinner animation; it is not persisted in history.
+    pub run_started_at: Option<Instant>,
    pub run_requests: usize,
    /// Sum of `input_tokens - cache_read_input_tokens` across the
    /// current turn's LLM requests — i.e. the net tokens this turn
@@ -281,6 +284,9 @@ pub struct App {
    /// records the instant; a second press within the timeout exits the
    /// TUI (the Worker itself stays alive).
    pub quit_confirm: Option<std::time::Instant>,
+    /// Independent 2-tap guard for `Ctrl-X` when the Worker is idle or
+    /// stopped. A second press within the timeout shuts down the Worker.
+    pub shutdown_confirm: Option<std::time::Instant>,
    /// Full display history in render order.
    pub blocks: Vec<Block>,
    /// Turn/protocol errors retained when a real `SegmentStart` replaces the
@@ -352,6 +358,7 @@ impl App {
            worker_status: WorkerStatus::Idle,
            running: false,
            paused: false,
+            run_started_at: None,
            run_requests: 0,
            run_upload_tokens: 0,
            run_output_tokens: 0,
@@ -369,6 +376,7 @@ impl App {
            command_completion_selected: None,
            quit: false,
            quit_confirm: None,
+            shutdown_confirm: None,
            blocks: Vec::new(),
            run_error_messages: Vec::new(),
            internal_workers: Vec::new(),
@@ -553,11 +561,18 @@ impl App {
    }

    pub fn set_worker_status(&mut self, status: WorkerStatus) {
+        let was_running = self.running;
        self.worker_status = status;
        self.running = status == WorkerStatus::Running;
        self.paused = status == WorkerStatus::Paused;
        if self.running {
+            if !was_running {
+                self.run_started_at = Some(Instant::now());
+            }
            self.quit_confirm = None;
+            self.shutdown_confirm = None;
+        } else {
+            self.run_started_at = None;
        }
    }

@@ -763,9 +778,23 @@ impl App {
        Some(self.method_for_run(segments))
    }

+    pub fn restore_unsent_run(&mut self, method: &Method) {
+        let Method::Run { input } = method else {
+            return;
+        };
+        self.pending_submit_rollback = None;
+        if self.input.is_empty() {
+            self.input.replace_with_segments(input);
+            self.completion = None;
+        } else {
+            self.queued_inputs
+                .push_front(QueuedInput::new(input.clone()));
+        }
+    }
+
    fn method_for_run(&mut self, segments: Vec<Segment>) -> Method {
        // TurnHeader / UserMessage blocks are pushed only after the Worker
-        // emits `Event::UserMessage` from a committed `LogEntry::UserInput`.
+        // emits `Event::UserMessage` from a committed `LogEntry::AnnotatedUserInput`.
        // Locally we only clear the input buffer and forward the method,
        // while remembering enough local state to undo the visible submit if
        // the accepted run produced no assistant output and was rolled back.
@@ -913,6 +942,10 @@ impl App {
        Some(self.method_for_run(queued.segments))
    }

+    pub fn clear_actionbar_notice(&mut self) {
+        self.actionbar_notice = None;
+    }
+
    pub fn push_error(&mut self, message: impl Into<String>) {
        self.blocks.push(Block::Alert {
            level: AlertLevel::Error,
@@ -1098,10 +1131,9 @@ impl App {
                self.blocks.push(Block::UserMessage { segments });
                self.assistant_streaming = false;
            }
-            Event::SegmentRotated { entry } => {
+            Event::SegmentRotated { session } => {
                let retained_run_errors = self.run_error_messages.clone();
-                self.reset_for_rotation();
-                self.apply_log_entry_raw(&entry);
+                self.restore_session(&session, self.greeting.clone());
                for message in retained_run_errors {
                    self.blocks.push(Block::Alert {
                        level: AlertLevel::Error,
@@ -1122,11 +1154,13 @@ impl App {
                self.latest_llm_wait_event = None;
                self.assistant_streaming = false;
            }
-            // UI consumers of Invoke / LlmCall semantics are out of scope
-            // for `tickets/invoke-turn-llmcall-semantics.md`; events flow
-            // through to subscribers but the TUI currently derives its
-            // turn header from `UserMessage` / `SystemItem` arrivals.
-            Event::InvokeStart { .. } | Event::LlmCallStart { .. } | Event::LlmCallEnd { .. } => {
+            Event::InvokeStart { .. } => {
+                self.set_worker_status(WorkerStatus::Running);
+            }
+            // UI consumers of per-attempt LlmCall semantics remain out of scope;
+            // the run-level status starts at InvokeStart and TurnStart counts each
+            // LLM request within that run.
+            Event::LlmCallStart { .. } | Event::LlmCallEnd { .. } => {
                self.latest_llm_wait_event = None;
            }
            Event::LlmRetry {
@@ -1244,6 +1278,7 @@ impl App {
                id,
                summary,
                output,
+                disposition: _,
                is_error,
            } => {
                self.latest_llm_wait_event = None;
@@ -1342,13 +1377,20 @@ impl App {
                    }
                }
            }
-            Event::CompactStart => {
+            Event::CompactStart { .. } => {
+                if self.last_streaming_compact_mut().is_none() {
                    self.blocks.push(Block::Compact(CompactEvent::Streaming {
                        started_at: Instant::now(),
                    }));
                }
-            Event::CompactDone { new_segment_id } => {
+            }
+            Event::CompactDone { lifecycle } => {
                self.session_context_tokens = 0;
+                let new_segment_id = lifecycle
+                    .new_segment_id
+                    .as_deref()
+                    .and_then(|value| uuid::Uuid::parse_str(value).ok())
+                    .unwrap_or_default();
                if let Some(evt) = self.last_streaming_compact_mut() {
                    let elapsed_secs = match evt {
                        CompactEvent::Streaming { started_at } => {
@@ -1367,7 +1409,10 @@ impl App {
                    }));
                }
            }
-            Event::CompactFailed { error } => {
+            Event::CompactFailed { lifecycle } => {
+                let error = lifecycle
+                    .error
+                    .unwrap_or_else(|| "compaction failed".to_string());
                if let Some(evt) = self.last_streaming_compact_mut() {
                    let elapsed_secs = match evt {
                        CompactEvent::Streaming { started_at } => {
@@ -1397,14 +1442,14 @@ impl App {
                self.latest_memory_worker_event = Some(event.message);
            }
            Event::Snapshot {
-                entries,
+                session,
                greeting,
                status,
                in_flight,
                internal_workers,
            } => {
                self.rewind_refresh_fence = false;
-                self.restore_snapshot(&entries, greeting, in_flight);
+                self.restore_snapshot(&session, greeting, in_flight);
                self.replace_internal_worker_snapshots(internal_workers);
                self.set_worker_status(status);
            }
@@ -1444,11 +1489,11 @@ impl App {
                }
            }
            Event::RewindApplied {
-                entries,
+                session,
                input,
                summary,
            } => {
-                self.restore_rewind_snapshot(&entries);
+                self.restore_rewind_snapshot(&session);
                self.rewind_refresh_fence = true;
                let restored_composer = if self.input.is_empty() {
                    self.input.replace_with_segments(&input);
@@ -2162,7 +2207,7 @@ impl App {
    ) -> InternalWorkerView {
        let mut app = App::new(snapshot.worker.name.clone());
        app.mode = mode;
-        app.restore_entries(&snapshot.entries, None);
+        app.restore_session(&snapshot.session, None);
        app.apply_in_flight_snapshot(snapshot.in_flight);
        app.set_worker_status(snapshot.status);
        if let Some(error) = snapshot.error {
@@ -2243,14 +2288,14 @@ impl App {

    fn restore_snapshot(
        &mut self,
-        entries: &[serde_json::Value],
+        session: &protocol::SessionSnapshot,
        greeting: protocol::Greeting,
        in_flight: InFlightSnapshot,
    ) {
        self.greeting = Some(greeting.clone());
        self.context_window = greeting.context_window;
        self.session_context_tokens = greeting.context_tokens;
-        self.restore_entries(entries, Some(greeting));
+        self.restore_session(session, Some(greeting));
        self.apply_in_flight_snapshot(in_flight);
    }

@@ -2259,7 +2304,7 @@ impl App {
    /// session tail; always clear/replay from it even if this TUI instance has
    /// somehow lost connect-time greeting metadata. Skipping the restore in
    /// that case would leave old post-target output visible after success.
-    fn restore_rewind_snapshot(&mut self, entries: &[serde_json::Value]) {
+    fn restore_rewind_snapshot(&mut self, session: &protocol::SessionSnapshot) {
        let greeting = self.greeting.clone().or_else(|| {
            self.blocks.iter().find_map(|b| match b {
                Block::Greeting(g) => Some(g.clone()),
@@ -2272,7 +2317,7 @@ impl App {
            self.session_context_tokens = greeting.context_tokens;
        }
        let missing_greeting = greeting.is_none();
-        self.restore_entries(entries, greeting);
+        self.restore_session(session, greeting);
        if missing_greeting {
            self.blocks.push(Block::Alert {
                level: AlertLevel::Warn,
@@ -2282,9 +2327,9 @@ impl App {
        }
    }

-    fn restore_entries(
+    fn restore_session(
        &mut self,
-        entries: &[serde_json::Value],
+        session: &protocol::SessionSnapshot,
        greeting: Option<protocol::Greeting>,
    ) {
        self.run_error_messages.clear();
@@ -2298,78 +2343,83 @@ impl App {
        }
        self.assistant_streaming = false;

-        for entry in entries {
-            self.apply_log_entry_raw(entry);
-        }
-
-        self.mark_orphan_tool_calls_incomplete_pass();
-    }
-
-    /// Drop the derived view in preparation for replaying a new
-    /// `SegmentStart` (compaction / fork). Greeting is preserved
-    /// because the Worker identity hasn't changed.
-    fn reset_for_rotation(&mut self) {
-        let greeting = self.blocks.iter().find_map(|b| match b {
-            Block::Greeting(g) => Some(g.clone()),
-            _ => None,
-        });
-        self.turn_index = 0;
-        self.blocks.clear();
-        self.cache = FileCache::new();
-        self.task_store = TaskStore::new();
-        self.task_pane_scroll = 0;
-        if let Some(g) = greeting {
-            self.greeting = Some(g.clone());
-            self.blocks.push(Block::Greeting(g));
-        }
-    }
-
-    /// Walk a single `LogEntry` JSON value and translate it into blocks
-    /// the live event path would have produced. Shared between
-    /// `restore_snapshot` (replay path) and `apply_log_entry` (live
-    /// path).
-    fn apply_log_entry_raw(&mut self, value: &serde_json::Value) {
-        let Ok(entry) = serde_json::from_value::<session_store::LogEntry>(value.clone()) else {
-            return;
-        };
-        match entry {
-            session_store::LogEntry::SegmentStart { history, .. } => {
-                for logged in history {
-                    let item: agen::Item = logged.into();
-                    let item_value = serde_json::to_value(&item).expect("Item is Serialize");
-                    self.push_history_item(&item_value);
-                }
-            }
-            session_store::LogEntry::UserInput { segments, .. } => {
+        for entry in &session.entries {
+            use protocol::{SessionContentPart, SessionMessageRole, SessionSnapshotEntryData};
+            match &entry.data {
+                SessionSnapshotEntryData::UserInput { segments } => {
                    self.turn_index += 1;
                    self.blocks.push(Block::TurnHeader {
                        turn: self.turn_index,
                    });
                    if !segments.is_empty() {
-                    self.blocks.push(Block::UserMessage { segments });
+                        self.blocks.push(Block::UserMessage {
+                            segments: segments.clone(),
+                        });
                    }
                }
-            session_store::LogEntry::AssistantItem { item, .. }
-            | session_store::LogEntry::ToolResult { item, .. } => {
-                let it: agen::Item = item.into();
-                let item_value = serde_json::to_value(&it).expect("Item is Serialize");
-                self.push_history_item(&item_value);
+                SessionSnapshotEntryData::Message { role, content } => {
+                    let role = match role {
+                        SessionMessageRole::User => agen::Role::User,
+                        SessionMessageRole::Assistant => agen::Role::Assistant,
+                    };
+                    let item = agen::Item::Message {
+                        id: None,
+                        role,
+                        content: content
+                            .iter()
+                            .map(|part| match part {
+                                SessionContentPart::Text { text } => {
+                                    agen::ContentPart::Text { text: text.clone() }
                                }
-            session_store::LogEntry::SystemItem { item, .. } => {
-                let value = serde_json::to_value(&item).expect("SystemItem is Serialize");
-                self.apply_system_item(&value);
+                                SessionContentPart::Refusal { refusal } => {
+                                    agen::ContentPart::Refusal {
+                                        refusal: refusal.clone(),
                                    }
-            session_store::LogEntry::Extension {
-                domain, payload, ..
-            } if domain == "yoi.compaction" => {
-                self.apply_compaction_extension(&payload);
                                }
-            session_store::LogEntry::RunErrored { message, .. } => {
-                self.push_run_error(message);
+                            })
+                            .collect(),
+                        status: None,
+                    };
+                    let value = serde_json::to_value(item).expect("Item is Serialize");
+                    self.push_history_item(&value);
                }
-            // Non-history-bearing variants don't affect the block view.
-            _ => {}
+                SessionSnapshotEntryData::ToolCall {
+                    call_id,
+                    name,
+                    arguments,
+                } => {
+                    let item =
+                        agen::Item::tool_call(call_id.clone(), name.clone(), arguments.clone());
+                    let value = serde_json::to_value(item).expect("Item is Serialize");
+                    self.push_history_item(&value);
                }
+                SessionSnapshotEntryData::ToolResult {
+                    call_id,
+                    summary,
+                    content,
+                    is_error,
+                    ..
+                } => {
+                    let item = agen::Item::tool_result_item(
+                        call_id.clone(),
+                        summary.clone(),
+                        content.clone(),
+                        *is_error,
+                    );
+                    let value = serde_json::to_value(item).expect("Item is Serialize");
+                    self.push_history_item(&value);
+                }
+                SessionSnapshotEntryData::SystemItem { data, .. } => {
+                    if let Some(data) = data {
+                        self.apply_system_item(data);
+                    }
+                }
+                SessionSnapshotEntryData::RunError { message } => {
+                    self.push_run_error(message.clone());
+                }
+            }
+        }
+        self.mark_orphan_tool_calls_incomplete_pass();
    }

    /// Dispatch one `SystemItem` JSON value into the appropriate block.
@@ -2377,58 +2427,6 @@ impl App {
    /// Kind-based routing replaces the old free-text `[Notification]` /
    /// `[File: …]` parsing path: each kind maps directly to a typed
    /// block (`Block::Notify`, `Block::WorkerEvent`, …).
-    fn apply_compaction_extension(&mut self, payload: &serde_json::Value) {
-        if payload.get("kind").and_then(|value| value.as_str()) != Some("compaction_block") {
-            return;
-        }
-        match payload.get("state").and_then(|value| value.as_str()) {
-            Some("running") => {
-                if self.last_streaming_compact_mut().is_none() {
-                    self.blocks.push(Block::Compact(CompactEvent::Streaming {
-                        started_at: Instant::now(),
-                    }));
-                }
-            }
-            Some("done") => {
-                let new_segment_id = payload
-                    .get("new_segment_id")
-                    .and_then(|value| value.as_str())
-                    .and_then(|value| value.parse::<uuid::Uuid>().ok())
-                    .unwrap_or_else(uuid::Uuid::nil);
-                if let Some(evt) = self.last_streaming_compact_mut() {
-                    *evt = CompactEvent::Done {
-                        new_segment_id,
-                        elapsed_secs: None,
-                    };
-                } else {
-                    self.blocks.push(Block::Compact(CompactEvent::Done {
-                        new_segment_id,
-                        elapsed_secs: None,
-                    }));
-                }
-            }
-            Some("failed") => {
-                let error = payload
-                    .get("error")
-                    .and_then(|value| value.as_str())
-                    .unwrap_or("compact failed")
-                    .to_string();
-                if let Some(evt) = self.last_streaming_compact_mut() {
-                    *evt = CompactEvent::Failed {
-                        error,
-                        elapsed_secs: None,
-                    };
-                } else {
-                    self.blocks.push(Block::Compact(CompactEvent::Failed {
-                        error,
-                        elapsed_secs: None,
-                    }));
-                }
-            }
-            _ => {}
-        }
-    }
-
    fn apply_system_item(&mut self, value: &serde_json::Value) {
        let Ok(item) = serde_json::from_value::<session_store::SystemItem>(value.clone()) else {
            // Unknown / forward-compat shape: fall back to rendering the
@@ -2486,7 +2484,7 @@ fn event_is_stale_after_rewind(event: &Event) -> bool {
        event,
        Event::Alert(_)
            | Event::MemoryWorker(_)
-            | Event::CompactStart
+            | Event::CompactStart { .. }
            | Event::CompactDone { .. }
            | Event::CompactFailed { .. }
            | Event::SegmentRotated { .. }
@@ -2531,6 +2529,15 @@ fn fmt_millis(ms: u64) -> String {
    }
 }

+#[cfg(test)]
+fn public_session(values: Vec<serde_json::Value>) -> protocol::SessionSnapshot {
+    let entries = values
+        .into_iter()
+        .map(|value| serde_json::from_value(value).expect("LogEntry deserializes"))
+        .collect::<Vec<session_store::LogEntry>>();
+    session_store::public_snapshot::project_current_session_snapshot(&entries)
+}
+
 fn message_text(item: &serde_json::Value) -> String {
    item["content"]
        .as_array()
@@ -2674,7 +2681,7 @@ mod rewind_refresh_tests {
        });

        app.handle_worker_event(Event::RewindApplied {
-            entries: vec![],
+            session: protocol::SessionSnapshot { entries: vec![] },
            input: vec![Segment::text("selected rewind input")],
            summary: summary(3),
        });
@@ -2693,7 +2700,7 @@ mod rewind_refresh_tests {
        });

        app.handle_worker_event(Event::RewindApplied {
-            entries: vec![],
+            session: protocol::SessionSnapshot { entries: vec![] },
            input: vec![Segment::text("rewound input")],
            summary: summary(1),
        });
@@ -2736,7 +2743,7 @@ mod rewind_refresh_tests {
        });

        app.handle_worker_event(Event::RewindApplied {
-            entries: vec![],
+            session: protocol::SessionSnapshot { entries: vec![] },
            input: vec![Segment::text("rewound input")],
            summary: summary(2),
        });
@@ -2965,6 +2972,17 @@ mod composer_history_persistence_tests {
 mod completion_flow_tests {
    use super::*;

+    fn annotated(item: agen::Item) -> session_store::LoggedHistoryEntry {
+        session_store::LoggedHistoryEntry {
+            item: session_store::LoggedItem::from(item),
+            metadata: session_store::LoggedSessionHistoryMetadata {
+                entry_id: session_store::LoggedSessionHistoryEntryId::new(),
+                origin: session_store::LoggedSessionHistoryOrigin::LegacyUnknown,
+                derivation: None,
+            },
+        }
+    }
+
    #[test]
    fn typing_at_creates_completion_state_and_emits_query() {
        let mut app = App::new("test".into());
@@ -3267,7 +3285,7 @@ mod completion_flow_tests {
    #[test]
    fn committed_user_message_survives_fresh_segment_rotation() {
        let mut app = App::new("test".into());
-        let start = session_store::LogEntry::SegmentStart {
+        let start = session_store::LogEntry::AnnotatedSegmentStart {
            ts: session_store::segment_log::now_millis(),
            session_id: uuid::Uuid::nil(),
            system_prompt: None,
@@ -3278,7 +3296,9 @@ mod completion_flow_tests {
        };

        app.handle_worker_event(Event::SegmentRotated {
-            entry: serde_json::to_value(start).expect("LogEntry is Serialize"),
+            session: public_session(vec![
+                serde_json::to_value(start).expect("LogEntry is Serialize"),
+            ]),
        });
        app.handle_worker_event(Event::UserMessage {
            segments: vec![Segment::text("first persisted message")],
@@ -3392,6 +3412,17 @@ mod completion_flow_tests {
        }
    }

+    #[test]
+    fn running_status_starts_and_stops_live_run_clock() {
+        let mut app = App::new("test".into());
+
+        app.set_worker_status(WorkerStatus::Running);
+        assert!(app.run_started_at.is_some());
+
+        app.set_worker_status(WorkerStatus::Idle);
+        assert!(app.run_started_at.is_none());
+    }
+
    #[test]
    fn running_submit_is_queued_locally_and_clears_composer() {
        let mut app = App::new("test".into());
@@ -3522,23 +3553,23 @@ mod completion_flow_tests {
    }

    #[test]
-    fn snapshot_renders_system_message_block_from_session_start() {
+    fn snapshot_excludes_system_prompt_history_from_public_blocks() {
        let mut app = App::new("test".into());
-        let session_start = session_store::LogEntry::SegmentStart {
+        let session_start = session_store::LogEntry::AnnotatedSegmentStart {
            ts: 1,
            session_id: uuid::Uuid::nil(),
            system_prompt: None,
            config: Default::default(),
-            history: vec![session_store::LoggedItem::from(
-                &agen::Item::system_message("[File: src/main.rs]\nfn main() {}"),
-            )],
+            history: vec![annotated(agen::Item::system_message(
+                "[File: src/main.rs]\nfn main() {}",
+            ))],
            forked_from: None,
            compacted_from: None,
        };
        let session_start_value = serde_json::to_value(&session_start).unwrap();
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
-            entries: vec![session_start_value],
+            session: public_session(vec![session_start_value]),
            status: WorkerStatus::Running,
            in_flight: Default::default(),
            internal_workers: Vec::new(),
@@ -3546,10 +3577,8 @@ mod completion_flow_tests {

        assert!(matches!(app.worker_status, WorkerStatus::Running));
        assert!(app.running);
-        assert!(matches!(
-            app.blocks.get(1),
-            Some(Block::SystemMessage { text }) if text == "[File: src/main.rs]\nfn main() {}"
-        ));
+        assert_eq!(app.blocks.len(), 1);
+        assert!(matches!(app.blocks.first(), Some(Block::Greeting(_))));
    }

    #[test]
@@ -3584,7 +3613,7 @@ mod completion_flow_tests {
        };
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
-            entries: vec![serde_json::to_value(run_errored).unwrap()],
+            session: public_session(vec![serde_json::to_value(run_errored).unwrap()]),
            status: WorkerStatus::Idle,
            in_flight: Default::default(),
            internal_workers: Vec::new(),
@@ -3612,7 +3641,7 @@ mod completion_flow_tests {
            code: ErrorCode::ProviderError,
            message: "provider unavailable".into(),
        });
-        let segment_start = session_store::LogEntry::SegmentStart {
+        let segment_start = session_store::LogEntry::AnnotatedSegmentStart {
            ts: 5,
            session_id: uuid::Uuid::nil(),
            system_prompt: None,
@@ -3622,7 +3651,7 @@ mod completion_flow_tests {
            compacted_from: None,
        };
        app.handle_worker_event(Event::SegmentRotated {
-            entry: serde_json::to_value(segment_start).unwrap(),
+            session: public_session(vec![serde_json::to_value(segment_start).unwrap()]),
        });

        let errors = app
@@ -3645,7 +3674,9 @@ mod completion_flow_tests {
        let mut app = App::new("test".into());
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
+            session: protocol::SessionSnapshot {
                entries: Vec::new(),
+            },
            status: WorkerStatus::Running,
            in_flight: InFlightSnapshot {
                blocks: vec![
@@ -3751,7 +3782,9 @@ mod completion_flow_tests {
            },
            revision,
            status: WorkerStatus::Idle,
+            session: protocol::SessionSnapshot {
                entries: Vec::new(),
+            },
            in_flight: protocol::InFlightSnapshot::default(),
            error: None,
            internal_workers: Vec::new(),
@@ -3966,7 +3999,9 @@ mod completion_flow_tests {
        assert_eq!(app.selected_worker_view().worker_name, "parent");
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
+            session: protocol::SessionSnapshot {
                entries: Vec::new(),
+            },
            status: WorkerStatus::Idle,
            in_flight: Default::default(),
            internal_workers: Vec::new(),
@@ -4015,7 +4050,9 @@ mod completion_flow_tests {
        });
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
+            session: protocol::SessionSnapshot {
                entries: Vec::new(),
+            },
            status: WorkerStatus::Idle,
            in_flight: Default::default(),
            internal_workers: vec![InternalWorkerSnapshot {
@@ -4026,7 +4063,9 @@ mod completion_flow_tests {
                    kind: protocol::InternalWorkerKind::SubWorker,
                },
                revision: 4,
+                session: protocol::SessionSnapshot {
                    entries: Vec::new(),
+                },
                status: WorkerStatus::Running,
                error: None,
                in_flight: Default::default(),
@@ -4076,13 +4115,34 @@ mod completion_flow_tests {
        }
    }

+    fn test_compaction_lifecycle(
+        state: protocol::CompactionLifecycleState,
+    ) -> protocol::CompactionLifecycle {
+        protocol::CompactionLifecycle {
+            schema_version: 2,
+            compaction_id: "compaction-test".into(),
+            revision: 1,
+            internal_worker: None,
+            state,
+            started_at_ms: 1,
+            ended_at_ms: None,
+            summary: None,
+            error: None,
+            new_segment_id: None,
+        }
+    }
+
    #[test]
    fn compact_done_replaces_live_block() {
        let mut app = App::new("test".into());
        let id = uuid::Uuid::parse_str("12345678-1234-5678-1234-567812345678").unwrap();

-        app.handle_worker_event(Event::CompactStart);
-        app.handle_worker_event(Event::CompactDone { new_segment_id: id });
+        app.handle_worker_event(Event::CompactStart {
+            lifecycle: test_compaction_lifecycle(protocol::CompactionLifecycleState::Running),
+        });
+        let mut lifecycle = test_compaction_lifecycle(protocol::CompactionLifecycleState::Done);
+        lifecycle.new_segment_id = Some(id.to_string());
+        app.handle_worker_event(Event::CompactDone { lifecycle });

        assert_eq!(compact_block_count(&app), 1);
        assert!(matches!(
@@ -4098,10 +4158,12 @@ mod completion_flow_tests {
    fn compact_failed_replaces_live_block() {
        let mut app = App::new("test".into());

-        app.handle_worker_event(Event::CompactStart);
-        app.handle_worker_event(Event::CompactFailed {
-            error: "provider 429".into(),
+        app.handle_worker_event(Event::CompactStart {
+            lifecycle: test_compaction_lifecycle(protocol::CompactionLifecycleState::Running),
        });
+        let mut lifecycle = test_compaction_lifecycle(protocol::CompactionLifecycleState::Failed);
+        lifecycle.error = Some("provider 429".into());
+        app.handle_worker_event(Event::CompactFailed { lifecycle });

        assert_eq!(compact_block_count(&app), 1);
        assert!(matches!(
@@ -4117,7 +4179,9 @@ mod completion_flow_tests {
    fn shutdown_marks_live_compact_incomplete() {
        let mut app = App::new("test".into());

-        app.handle_worker_event(Event::CompactStart);
+        app.handle_worker_event(Event::CompactStart {
+            lifecycle: test_compaction_lifecycle(protocol::CompactionLifecycleState::Running),
+        });
        app.handle_worker_event(Event::Shutdown);

        assert!(app.quit);
@@ -4157,7 +4221,9 @@ mod completion_flow_tests {
        greeting.context_tokens = 45_000;

        app.handle_worker_event(Event::Snapshot {
+            session: protocol::SessionSnapshot {
                entries: Vec::new(),
+            },
            greeting,
            status: WorkerStatus::Idle,
            in_flight: Default::default(),
@@ -4208,9 +4274,9 @@ mod completion_flow_tests {
        let mut app = App::new("test".into());
        app.session_context_tokens = 42_000;

-        app.handle_worker_event(Event::CompactDone {
-            new_segment_id: uuid::Uuid::nil(),
-        });
+        let mut lifecycle = test_compaction_lifecycle(protocol::CompactionLifecycleState::Done);
+        lifecycle.new_segment_id = Some(uuid::Uuid::nil().to_string());
+        app.handle_worker_event(Event::CompactDone { lifecycle });

        assert_eq!(app.session_context_tokens, 0);
    }
@@ -4327,40 +4393,37 @@ mod completion_flow_tests {
        });

        let assistant_item_entries = vec![
-            serde_json::json!({
-                "kind": "assistant_item",
-                "ts": 1,
-                "item": {
-                    "kind": "tool_call",
-                    "call_id": "c1",
-                    "name": "TaskCreate",
-                    "arguments": r#"{"subject":"a","description":"A"}"#,
-                },
-            }),
-            serde_json::json!({
-                "kind": "assistant_item",
-                "ts": 2,
-                "item": {
-                    "kind": "tool_call",
-                    "call_id": "c2",
-                    "name": "TaskCreate",
-                    "arguments": r#"{"subject":"b","description":"B"}"#,
-                },
-            }),
-            serde_json::json!({
-                "kind": "assistant_item",
-                "ts": 3,
-                "item": {
-                    "kind": "tool_call",
-                    "call_id": "u1",
-                    "name": "TaskUpdate",
-                    "arguments": r#"{"taskid":2,"status":"inprogress"}"#,
-                },
-            }),
+            serde_json::to_value(session_store::LogEntry::AnnotatedAssistantItem {
+                ts: 1,
+                entry: annotated(agen::Item::tool_call(
+                    "c1",
+                    "TaskCreate",
+                    r#"{"subject":"a","description":"A"}"#,
+                )),
+            })
+            .unwrap(),
+            serde_json::to_value(session_store::LogEntry::AnnotatedAssistantItem {
+                ts: 2,
+                entry: annotated(agen::Item::tool_call(
+                    "c2",
+                    "TaskCreate",
+                    r#"{"subject":"b","description":"B"}"#,
+                )),
+            })
+            .unwrap(),
+            serde_json::to_value(session_store::LogEntry::AnnotatedAssistantItem {
+                ts: 3,
+                entry: annotated(agen::Item::tool_call(
+                    "u1",
+                    "TaskUpdate",
+                    r#"{"taskid":2,"status":"inprogress"}"#,
+                )),
+            })
+            .unwrap(),
        ];
        app.handle_worker_event(Event::Snapshot {
            greeting: test_greeting(),
-            entries: assistant_item_entries,
+            session: public_session(assistant_item_entries),
            status: WorkerStatus::Running,
            in_flight: Default::default(),
            internal_workers: Vec::new(),
@@ -7,15 +7,15 @@ use client::{
    list_backend_workers, restore_backend_worker,
 };
 use crossterm::event::{self, Event as TermEvent, KeyCode, KeyEventKind, KeyModifiers};
-use ratatui::backend::CrosstermBackend;
+use ratatui::Frame;
 use ratatui::layout::{Constraint, Layout};
 use ratatui::style::{Color, Modifier, Style};
 use ratatui::text::{Line, Span};
 use ratatui::widgets::Paragraph;
-use ratatui::{Frame, Terminal, TerminalOptions, Viewport};

 use crate::backend_workspace_picker::select_backend_workspace;
 use crate::console;
+use crate::inline_terminal::with_inline_terminal;

 const MAX_ROWS: usize = 10;
 const VIEWPORT_LINES: u16 = MAX_ROWS as u16 + 4;
@@ -127,7 +127,9 @@ fn pick_worker(
    workers.truncate(MAX_ROWS);

    let mut state = BackendWorkerPickerState::new(target, workers);
-    let mut terminal = make_inline_terminal()?;
+    with_inline_terminal(
+        VIEWPORT_LINES,
+        |terminal| -> Result<_, Box<dyn std::error::Error>> {
            loop {
                terminal.draw(|frame| draw(frame, &state))?;
                match poll_event()? {
@@ -135,23 +137,22 @@ fn pick_worker(
                    Some(Action::Up) => state.previous(),
                    Some(Action::Down) => state.next(),
                    Some(Action::Submit) => {
-                close_viewport(&mut terminal)?;
                        return Ok(WorkerPickerResult::Selected(
                            state.selected_worker().clone(),
                        ));
                    }
                    Some(Action::SwitchWorkspace) => {
-                close_viewport(&mut terminal)?;
                        return Ok(WorkerPickerResult::SwitchWorkspace);
                    }
                    Some(Action::Cancel) => {
-                close_viewport(&mut terminal)?;
                        return Err(Box::new(io::Error::other(
                            "Backend worker picker cancelled",
                        )));
                    }
                }
            }
+        },
+    )
 }

 struct BackendWorkerPickerState {
@@ -184,27 +185,6 @@ impl BackendWorkerPickerState {
    }
 }

-fn make_inline_terminal() -> io::Result<Terminal<CrosstermBackend<io::Stdout>>> {
-    let backend = CrosstermBackend::new(io::stdout());
-    Terminal::with_options(
-        backend,
-        TerminalOptions {
-            viewport: Viewport::Inline(VIEWPORT_LINES),
-        },
-    )
-}
-
-fn close_viewport(terminal: &mut Terminal<CrosstermBackend<io::Stdout>>) -> io::Result<()> {
-    let area = terminal.get_frame().area();
-    let last_row = area.bottom().saturating_sub(1);
-    terminal.set_cursor_position((0, last_row))?;
-    use std::io::Write;
-    let mut out = io::stdout();
-    out.write_all(b"\r\n")?;
-    out.flush()?;
-    Ok(())
-}
-
 enum Action {
    Up,
    Down,
@@ -370,7 +350,7 @@ fn working_directory_text(worker: &BackendWorkerSummary) -> String {
    let cleanliness = wd.cleanliness.as_deref().unwrap_or("unknown");
    format!(
        "wd:{}:{} {} {}",
-        wd.repository_id, wd.working_directory_id, wd.status, cleanliness
+        wd.repository_key, wd.working_directory_id, wd.status, cleanliness
    )
 }

@@ -1,784 +0,0 @@
-use super::*;
-
-pub(super) fn draw(frame: &mut Frame<'_>, app: &mut DashboardApp) {
-    let area = frame.area();
-    let input_content_width = area.width.saturating_sub(2).max(1);
-    let mut input_render = app.input.render(input_content_width);
-    let input_height = input_area_height(&input_render, area.height);
-    app.input
-        .apply_cursor_viewport(&mut input_render, input_height);
-    let layout = dashboard_layout(area, input_height);
-
-    draw_title(frame, app, layout.title);
-    draw_list(frame, app, layout.list);
-    draw_separator(frame, layout.boundary);
-    draw_target_status(frame, app, layout.target_status);
-    draw_input(frame, &input_render, layout.input);
-    draw_actionbar(frame, app, layout.actionbar);
-    if app.panel_diagnostic_open {
-        render_panel_diagnostic(frame, app, area);
-    }
-}
-
-pub(super) fn panel_diagnostic_area(area: Rect) -> Rect {
-    let width = if area.width <= 20 {
-        area.width
-    } else {
-        area.width.saturating_sub(4).min(100).max(20)
-    };
-    let height = if area.height <= 8 {
-        area.height
-    } else {
-        area.height.saturating_sub(4).min(24).max(8)
-    };
-    let x = area.x + area.width.saturating_sub(width) / 2;
-    let y = area.y + area.height.saturating_sub(height) / 2;
-    Rect::new(x, y, width, height)
-}
-
-pub(super) fn render_panel_diagnostic(frame: &mut Frame<'_>, app: &DashboardApp, area: Rect) {
-    let Some(diagnostic) = app.panel_diagnostic.as_ref() else {
-        return;
-    };
-    let popup_area = panel_diagnostic_area(area);
-    let title = format!(" {} ", diagnostic.title);
-    let text = format!("{}\n\nF2/Esc: close", diagnostic.details);
-    let paragraph = Paragraph::new(text)
-        .block(Block::default().title(title).borders(Borders::ALL))
-        .wrap(Wrap { trim: false });
-    frame.render_widget(Clear, popup_area);
-    frame.render_widget(paragraph, popup_area);
-}
-
-pub(super) fn input_area_height(render: &crate::input::InputRender, terminal_height: u16) -> u16 {
-    let needed = render.lines.len().max(1) as u16;
-    let cap = (terminal_height / 3).max(1).min(10);
-    needed.clamp(1, cap)
-}
-
-pub(super) fn draw_title(frame: &mut Frame<'_>, app: &DashboardApp, area: Rect) {
-    frame.render_widget(Paragraph::new(title_line(app)), area);
-}
-
-pub(super) fn title_line(app: &DashboardApp) -> Line<'static> {
-    let mut spans = vec![Span::styled(
-        "workspace dashboard",
-        Style::default().add_modifier(Modifier::BOLD),
-    )];
-    if let Some(companion) = &app.panel.header.companion {
-        spans.push(Span::styled(
-            " · companion ",
-            Style::default().fg(Color::DarkGray),
-        ));
-        spans.push(Span::styled(
-            companion.status.label(),
-            companion_status_style(companion.status),
-        ));
-        if let Some(detail) = companion.detail.as_deref() {
-            spans.push(Span::styled(
-                format!(" ({detail})"),
-                Style::default().fg(Color::DarkGray),
-            ));
-        }
-    }
-    if let Some(orchestrator) = &app.panel.header.orchestrator {
-        spans.push(Span::styled(
-            " · orchestrator ",
-            Style::default().fg(Color::DarkGray),
-        ));
-        spans.push(Span::styled(
-            orchestrator.status.label(),
-            orchestrator_status_style(orchestrator.status),
-        ));
-    }
-    Line::from(spans)
-}
-
-pub(super) fn companion_status_style(status: CompanionPanelStatus) -> Style {
-    match status {
-        CompanionPanelStatus::Live
-        | CompanionPanelStatus::Restored
-        | CompanionPanelStatus::Spawned => Style::default().fg(Color::Green),
-        CompanionPanelStatus::Stopped | CompanionPanelStatus::Missing => {
-            Style::default().fg(Color::Yellow)
-        }
-        CompanionPanelStatus::Unavailable => Style::default().fg(Color::Red),
-    }
-}
-
-pub(super) fn orchestrator_status_style(status: OrchestratorPanelStatus) -> Style {
-    match status {
-        OrchestratorPanelStatus::Live
-        | OrchestratorPanelStatus::Restored
-        | OrchestratorPanelStatus::Spawned => Style::default().fg(Color::Green),
-        OrchestratorPanelStatus::Stopped | OrchestratorPanelStatus::Missing => {
-            Style::default().fg(Color::Yellow)
-        }
-        OrchestratorPanelStatus::Unavailable => Style::default().fg(Color::Red),
-    }
-}
-
-pub(super) fn draw_list(frame: &mut Frame<'_>, app: &mut DashboardApp, area: Rect) {
-    if area.width == 0 || area.height == 0 {
-        app.row_hit_boxes.clear();
-        return;
-    }
-    let rows = list_rows(app, area.width, area.height);
-    app.set_row_hit_boxes(&rows, area);
-    let lines = rows.into_iter().map(|row| row.line).collect::<Vec<_>>();
-    Paragraph::new(lines).render(area, frame.buffer_mut());
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub(super) struct PanelListRow {
-    pub(super) line: Line<'static>,
-    pub(super) key: Option<PanelRowKey>,
-}
-
-impl PanelListRow {
-    fn inert(line: Line<'static>) -> Self {
-        Self { line, key: None }
-    }
-
-    fn selectable(line: Line<'static>, key: PanelRowKey) -> Self {
-        Self {
-            line,
-            key: Some(key),
-        }
-    }
-}
-
-#[cfg(test)]
-pub(super) fn list_lines(app: &DashboardApp, width: u16, height: u16) -> Vec<Line<'static>> {
-    list_rows(app, width, height)
-        .into_iter()
-        .map(|row| row.line)
-        .collect()
-}
-
-pub(super) fn list_rows(app: &DashboardApp, width: u16, height: u16) -> Vec<PanelListRow> {
-    let sections = sectioned_entries(&app.list);
-    let selected = app.selected_row.as_ref();
-    let diagnostic_rows = panel_diagnostic_lines(&app.panel, width)
-        .into_iter()
-        .map(PanelListRow::inert)
-        .collect::<Vec<_>>();
-    let action_rows = panel_action_rows(&app.panel, selected, width);
-    let live_rows = sections
-        .iter()
-        .filter(|section| section.kind != DashboardSectionKind::Closed)
-        .flat_map(|section| section_rows(&app.list, section, selected, width))
-        .collect::<Vec<_>>();
-    let closed_rows = sections
-        .iter()
-        .find(|section| section.kind == DashboardSectionKind::Closed)
-        .map(|section| section_rows(&app.list, section, selected, width))
-        .unwrap_or_default();
-
-    let available = height as usize;
-    let diagnostic_len = diagnostic_rows.len().min(available);
-    let remaining_after_diagnostics = available.saturating_sub(diagnostic_len);
-    let action_len = action_rows.len().min(remaining_after_diagnostics);
-    let remaining_after_actions = remaining_after_diagnostics.saturating_sub(action_len);
-    let closed_len = closed_rows.len().min(remaining_after_actions);
-    let live_len = live_rows
-        .len()
-        .min(remaining_after_actions.saturating_sub(closed_len));
-    let spacer_len = available.saturating_sub(diagnostic_len + action_len + live_len + closed_len);
-
-    let mut rows = Vec::with_capacity(available);
-    rows.extend(diagnostic_rows.into_iter().take(diagnostic_len));
-    rows.extend(action_rows.into_iter().take(action_len));
-    rows.extend(live_rows.into_iter().take(live_len));
-    rows.extend(
-        std::iter::repeat_with(|| PanelListRow::inert(Line::from(Span::raw("")))).take(spacer_len),
-    );
-    rows.extend(closed_rows.into_iter().take(closed_len));
-    rows
-}
-
-pub(super) fn row_hit_boxes(rows: &[PanelListRow], area: Rect) -> Vec<PanelRowHitBox> {
-    if area.width == 0 || area.height == 0 {
-        return Vec::new();
-    }
-
-    let mut hit_boxes: Vec<PanelRowHitBox> = Vec::new();
-    for (offset, row) in rows.iter().enumerate() {
-        let Some(key) = row.key.clone() else {
-            continue;
-        };
-        let Some(y) = area.y.checked_add(offset as u16) else {
-            continue;
-        };
-        if y >= area.y.saturating_add(area.height) {
-            continue;
-        }
-        if let Some(last) = hit_boxes.last_mut() {
-            if last.key == key
-                && last.rect.x == area.x
-                && last.rect.width == area.width
-                && last.rect.y.saturating_add(last.rect.height) == y
-            {
-                last.rect.height = last.rect.height.saturating_add(1);
-                continue;
-            }
-        }
-        hit_boxes.push(PanelRowHitBox {
-            rect: Rect::new(area.x, y, area.width, 1),
-            key,
-        });
-    }
-    hit_boxes
-}
-
-pub(super) fn panel_diagnostic_lines(
-    panel: &WorkspacePanelViewModel,
-    width: u16,
-) -> Vec<Line<'static>> {
-    panel
-        .header
-        .diagnostics
-        .iter()
-        .map(|diagnostic| {
-            Line::from(vec![
-                Span::styled("⚠ ", Style::default().fg(Color::Yellow)),
-                Span::styled(
-                    truncate_with_ellipsis(diagnostic, width.saturating_sub(2) as usize),
-                    Style::default().fg(Color::Yellow),
-                ),
-            ])
-        })
-        .collect()
-}
-
-pub(super) fn panel_action_rows(
-    panel: &WorkspacePanelViewModel,
-    selected: Option<&PanelRowKey>,
-    width: u16,
-) -> Vec<PanelListRow> {
-    let rows = panel
-        .rows
-        .iter()
-        .filter(|row| row.is_ticket_section_row())
-        .collect::<Vec<_>>();
-    if rows.is_empty() {
-        return Vec::new();
-    }
-    let mut lines = Vec::with_capacity((rows.len() * 2) + 1);
-    lines.push(PanelListRow::inert(panel_action_header_line(
-        rows.len(),
-        width,
-    )));
-    for row in rows {
-        for line in panel_row_lines(row, selected == Some(&row.key), width) {
-            lines.push(PanelListRow::selectable(line, row.key.clone()));
-        }
-    }
-    lines
-}
-
-pub(super) fn panel_action_header_line(total: usize, width: u16) -> Line<'static> {
-    let detail = if total == 1 {
-        " 1 row".to_string()
-    } else {
-        format!(" {total} rows")
-    };
-    let text = truncate_with_ellipsis(&format!("--tickets{detail}---"), width as usize);
-    Line::from(Span::styled(
-        text,
-        Style::default()
-            .fg(Color::DarkGray)
-            .add_modifier(Modifier::BOLD),
-    ))
-}
-
-pub(super) const TICKET_STATE_COLUMN_WIDTH: usize = 10;
-pub(super) const POD_STATUS_COLUMN_WIDTH: usize = 18;
-
-pub(super) fn panel_row_lines(row: &PanelRow, selected: bool, width: u16) -> Vec<Line<'static>> {
-    if row.kind == PanelRowKind::TicketIntakeWorker {
-        vec![panel_intake_child_line(row, selected, width)]
-    } else {
-        vec![
-            panel_row_title_line(row, selected, width),
-            panel_row_detail_line(row, selected, width),
-        ]
-    }
-}
-
-pub(super) fn panel_row_title_line(row: &PanelRow, selected: bool, width: u16) -> Line<'static> {
-    let title_style = if selected {
-        Style::default()
-            .fg(Color::Magenta)
-            .add_modifier(Modifier::BOLD)
-    } else {
-        Style::default().fg(Color::Magenta)
-    };
-    let mut spans = Vec::new();
-    let mut remaining = width as usize;
-
-    push_ticket_primary_marker_span(&mut spans, selected, &mut remaining);
-    push_column_span(
-        &mut spans,
-        &row.status,
-        TICKET_STATE_COLUMN_WIDTH,
-        panel_priority_style(row.priority),
-        &mut remaining,
-    );
-    push_bounded_span(&mut spans, row.title.as_str(), title_style, &mut remaining);
-
-    Line::from(spans)
-}
-
-pub(super) fn panel_intake_child_line(row: &PanelRow, selected: bool, width: u16) -> Line<'static> {
-    let title_style = if selected {
-        Style::default()
-            .fg(Color::Cyan)
-            .add_modifier(Modifier::BOLD)
-    } else {
-        Style::default().fg(Color::Cyan)
-    };
-    let mut spans = Vec::new();
-    let mut remaining = width as usize;
-
-    push_intake_child_marker_span(&mut spans, selected, &mut remaining);
-    push_column_span(
-        &mut spans,
-        &row.status,
-        TICKET_STATE_COLUMN_WIDTH,
-        intake_status_style(&row.status),
-        &mut remaining,
-    );
-    push_bounded_span(&mut spans, row.title.as_str(), title_style, &mut remaining);
-
-    Line::from(spans)
-}
-
-pub(super) fn panel_row_detail_line(row: &PanelRow, selected: bool, width: u16) -> Line<'static> {
-    let mut spans = Vec::new();
-    let mut remaining = width as usize;
-
-    push_ticket_detail_marker_span(&mut spans, selected, &mut remaining);
-    push_bounded_span(
-        &mut spans,
-        "meta ",
-        Style::default().fg(Color::DarkGray),
-        &mut remaining,
-    );
-    push_bounded_span(
-        &mut spans,
-        &panel_ticket_detail(row),
-        ticket_detail_style(row),
-        &mut remaining,
-    );
-
-    Line::from(spans)
-}
-
-pub(super) fn push_ticket_primary_marker_span(
-    spans: &mut Vec<Span<'static>>,
-    selected: bool,
-    remaining: &mut usize,
-) {
-    let (marker, style) = if selected {
-        (
-            "▶ ",
-            Style::default()
-                .fg(Color::Magenta)
-                .add_modifier(Modifier::BOLD),
-        )
-    } else {
-        ("  ", Style::default().fg(Color::DarkGray))
-    };
-    push_bounded_span(spans, marker, style, remaining);
-}
-
-pub(super) fn push_ticket_detail_marker_span(
-    spans: &mut Vec<Span<'static>>,
-    selected: bool,
-    remaining: &mut usize,
-) {
-    let (marker, style) = if selected {
-        (
-            "│ ",
-            Style::default()
-                .fg(Color::Magenta)
-                .add_modifier(Modifier::BOLD),
-        )
-    } else {
-        ("  ", Style::default().fg(Color::DarkGray))
-    };
-    push_bounded_span(spans, marker, style, remaining);
-}
-
-pub(super) fn push_intake_child_marker_span(
-    spans: &mut Vec<Span<'static>>,
-    selected: bool,
-    remaining: &mut usize,
-) {
-    let (marker, style) = if selected {
-        (
-            "  ▶ ",
-            Style::default()
-                .fg(Color::Cyan)
-                .add_modifier(Modifier::BOLD),
-        )
-    } else {
-        ("  └ ", Style::default().fg(Color::DarkGray))
-    };
-    push_bounded_span(spans, marker, style, remaining);
-}
-
-pub(super) fn panel_ticket_detail(row: &PanelRow) -> String {
-    if row.kind == PanelRowKind::InvalidTicket {
-        let mut parts = vec![panel_ticket_reference(row), "Gate: unavailable".to_string()];
-        if let Some(reason) = panel_ticket_reason(row) {
-            parts.push(format!("Reason: {reason}"));
-        }
-        return parts.join(" · ");
-    }
-
-    if row.kind == PanelRowKind::TicketIntakeWorker {
-        let mut parts = row
-            .subtitle
-            .as_ref()
-            .map(|subtitle| vec![subtitle.clone()])
-            .unwrap_or_else(|| vec![panel_ticket_reference(row)]);
-        if let Some(action) = row.next_action {
-            parts.push(format!("Action: {}", action.label()));
-        }
-        if let Some(reason) = panel_ticket_reason(row) {
-            parts.push(format!("Reason: {reason}"));
-        }
-        return parts.join(" · ");
-    }
-
-    let mut parts = vec![panel_ticket_reference(row)];
-    if let Some(overlay_detail) = panel_ticket_overlay_detail(row) {
-        parts.push(overlay_detail);
-    }
-    if let Some(blocked_reason) = row
-        .ticket
-        .as_ref()
-        .and_then(|ticket| ticket.blocked_reason.as_deref())
-    {
-        parts.push(format!("Gate: waiting for {blocked_reason}"));
-    } else {
-        parts.push("Gate: clear".to_string());
-    }
-    if let Some(action) = row.next_action {
-        parts.push(format!(
-            "Action: {}",
-            panel_ticket_action_label(row, action)
-        ));
-    }
-    if let Some(reason) = panel_ticket_reason(row) {
-        parts.push(format!("Reason: {reason}"));
-    }
-    parts.join(" · ")
-}
-
-pub(super) fn panel_ticket_action_label(row: &PanelRow, action: NextUserAction) -> &'static str {
-    if action == NextUserAction::Wait
-        && row
-            .ticket
-            .as_ref()
-            .and_then(|ticket| ticket.blocked_reason.as_ref())
-            .is_some()
-    {
-        "queue disabled"
-    } else {
-        action.label()
-    }
-}
-
-pub(super) fn panel_ticket_overlay_detail(row: &PanelRow) -> Option<String> {
-    let ticket = row.ticket.as_ref()?;
-    let overlay = ticket.orchestration_overlay.as_ref()?;
-    let mut detail = format!(
-        "Overlay: local {} · {} {}",
-        ticket.workflow_state.as_str(),
-        overlay.source,
-        overlay.workflow_state.as_str()
-    );
-    if matches!(
-        overlay.workflow_state,
-        TicketWorkflowState::Done | TicketWorkflowState::Closed
-    ) {
-        detail.push_str(" · merge pending");
-    }
-    Some(detail)
-}
-
-pub(super) fn panel_ticket_reason(row: &PanelRow) -> Option<&str> {
-    row.disabled_reason
-        .as_deref()
-        .or_else(|| row.key_hint.as_deref())
-}
-
-pub(super) fn ticket_detail_style(row: &PanelRow) -> Style {
-    if row.kind == PanelRowKind::InvalidTicket {
-        return Style::default().fg(Color::Yellow);
-    }
-    if row
-        .ticket
-        .as_ref()
-        .and_then(|ticket| ticket.blocked_reason.as_ref())
-        .is_some()
-    {
-        Style::default().fg(Color::Yellow)
-    } else {
-        Style::default().fg(Color::DarkGray)
-    }
-}
-
-pub(super) fn panel_ticket_reference(row: &PanelRow) -> String {
-    row.ticket
-        .as_ref()
-        .map(|ticket| {
-            ticket
-                .resource_key
-                .clone()
-                .unwrap_or_else(|| "resource key unavailable".to_string())
-        })
-        .unwrap_or_else(|| match &row.key {
-            PanelRowKey::Ticket(id) | PanelRowKey::InvalidTicket(id) => id.clone(),
-            PanelRowKey::TicketIntakeWorker { ticket_id, .. } => ticket_id.clone(),
-            PanelRowKey::Worker(name) => name.clone(),
-        })
-}
-
-pub(super) fn push_column_span(
-    spans: &mut Vec<Span<'static>>,
-    value: &str,
-    column_width: usize,
-    style: Style,
-    remaining: &mut usize,
-) {
-    if *remaining == 0 {
-        return;
-    }
-    let mut content = padded_cell(value, column_width);
-    content.push(' ');
-    push_bounded_span(spans, &content, style, remaining);
-}
-
-pub(super) fn push_bounded_span(
-    spans: &mut Vec<Span<'static>>,
-    value: &str,
-    style: Style,
-    remaining: &mut usize,
-) {
-    if *remaining == 0 || value.is_empty() {
-        return;
-    }
-    let content = truncate_with_ellipsis(value, *remaining);
-    *remaining = remaining.saturating_sub(content.width());
-    spans.push(Span::styled(content, style));
-}
-
-pub(super) fn padded_cell(value: &str, width: usize) -> String {
-    let mut cell = truncate_with_ellipsis(value, width);
-    let padding = width.saturating_sub(cell.width());
-    cell.extend(std::iter::repeat_n(' ', padding));
-    cell
-}
-
-pub(super) fn panel_priority_style(priority: ActionPriority) -> Style {
-    match priority {
-        ActionPriority::ReadyForQueue => Style::default().fg(Color::Green),
-        ActionPriority::ActiveWork => Style::default().fg(Color::Cyan),
-        ActionPriority::Background => Style::default().fg(Color::DarkGray),
-    }
-}
-
-pub(super) fn intake_status_style(status: &str) -> Style {
-    match status {
-        "live" => Style::default().fg(Color::Green),
-        "restorable" => Style::default().fg(Color::Yellow),
-        "stale" => Style::default().fg(Color::DarkGray),
-        _ => Style::default().fg(Color::Cyan),
-    }
-}
-
-pub(super) fn section_rows(
-    list: &WorkerList,
-    section: &DashboardSection,
-    selected: Option<&PanelRowKey>,
-    width: u16,
-) -> Vec<PanelListRow> {
-    let visible = visible_section_indices(section);
-    if visible.is_empty() {
-        return Vec::new();
-    }
-
-    let mut rows = Vec::with_capacity(visible.len() + 1);
-    rows.push(PanelListRow::inert(section_header_line(
-        section.kind,
-        section.entries.len(),
-        section.hidden_count(),
-        width,
-    )));
-    for index in visible {
-        if let Some(entry) = list.entries.get(index) {
-            let key = PanelRowKey::Worker(entry.name.clone());
-            let selected = selected == Some(&key);
-            rows.push(PanelListRow::selectable(
-                row_line(entry, selected, width),
-                key,
-            ));
-        }
-    }
-    rows
-}
-
-pub(super) fn row_line(entry: &WorkerListEntry, selected: bool, width: u16) -> Line<'static> {
-    let marker = if selected { "▶ " } else { "  " };
-    let name_style = if selected {
-        Style::default()
-            .fg(Color::Cyan)
-            .add_modifier(Modifier::BOLD)
-    } else {
-        Style::default().fg(Color::Cyan)
-    };
-    let (status, status_style) = row_status_label(entry);
-    let mut spans = Vec::new();
-    let mut remaining = width as usize;
-
-    push_bounded_span(
-        &mut spans,
-        marker,
-        if selected {
-            Style::default()
-                .fg(Color::Cyan)
-                .add_modifier(Modifier::BOLD)
-        } else {
-            Style::default().fg(Color::DarkGray)
-        },
-        &mut remaining,
-    );
-    push_column_span(
-        &mut spans,
-        status,
-        POD_STATUS_COLUMN_WIDTH,
-        status_style,
-        &mut remaining,
-    );
-    push_bounded_span(&mut spans, entry.name.as_str(), name_style, &mut remaining);
-
-    Line::from(spans)
-}
-
-pub(super) fn draw_separator(frame: &mut Frame<'_>, area: Rect) {
-    frame.render_widget(
-        Paragraph::new(Line::from(Span::styled(
-            "─".repeat(area.width as usize),
-            Style::default().fg(Color::DarkGray),
-        ))),
-        area,
-    );
-}
-
-pub(super) fn draw_target_status(frame: &mut Frame<'_>, app: &DashboardApp, area: Rect) {
-    frame.render_widget(Paragraph::new(target_status_line(app)), area);
-}
-
-pub(super) fn target_status_line(_app: &DashboardApp) -> Line<'static> {
-    Line::from(Span::raw(""))
-}
-
-pub(super) fn draw_input(frame: &mut Frame<'_>, render: &crate::input::InputRender, area: Rect) {
-    let mut lines: Vec<Line<'static>> = Vec::with_capacity(render.lines.len());
-    for (i, src) in render.lines.iter().enumerate() {
-        let absolute_row = render.viewport_start_row as usize + i;
-        let prefix = if absolute_row == 0 { "> " } else { "  " };
-        let mut spans = vec![Span::styled(prefix, Style::default().fg(Color::DarkGray))];
-        spans.extend(src.spans.iter().cloned());
-        lines.push(Line::from(spans));
-    }
-    frame.render_widget(Paragraph::new(lines), area);
-
-    let cursor_x = area.x + 2 + render.cursor_col;
-    let cursor_y = area.y + render.cursor_row;
-    if cursor_y < area.y + area.height {
-        frame.set_cursor_position(Position::new(cursor_x, cursor_y));
-    }
-}
-
-pub(super) fn actionbar_left_text(app: &DashboardApp) -> String {
-    if app.sending && app.composer_target() == ComposerTarget::TicketIntake {
-        "launching Ticket Intake…".to_string()
-    } else if app.sending {
-        "working…".to_string()
-    } else if app.refreshing {
-        match app.notice.as_deref() {
-            Some(notice) if notice.contains("Refreshing") || notice.contains("refreshing") => {
-                notice.to_string()
-            }
-            Some(notice) => format!("{notice} Refreshing workspace…"),
-            None => "Refreshing workspace…".to_string(),
-        }
-    } else if let Some(notice) = app.notice.as_deref() {
-        notice.to_string()
-    } else {
-        String::new()
-    }
-}
-
-pub(super) fn actionbar_right_text(app: &DashboardApp) -> &'static str {
-    if app.panel_diagnostic_open {
-        "F2/Esc close details"
-    } else if app.panel_diagnostic.is_some() {
-        "F2 details"
-    } else {
-        ""
-    }
-}
-
-pub(super) fn draw_actionbar(frame: &mut Frame<'_>, app: &DashboardApp, area: Rect) {
-    let left = actionbar_left_text(app);
-    let right = actionbar_right_text(app);
-    let left_width = area
-        .width
-        .saturating_sub(right.width() as u16)
-        .saturating_sub(2) as usize;
-    frame.render_widget(
-        Paragraph::new(Line::from(Span::styled(
-            truncate_with_ellipsis(&left, left_width),
-            Style::default().fg(Color::DarkGray),
-        ))),
-        area,
-    );
-    frame.render_widget(
-        Paragraph::new(Line::from(Span::styled(
-            right,
-            Style::default().fg(Color::DarkGray),
-        )))
-        .alignment(ratatui::layout::Alignment::Right),
-        area,
-    );
-}
-
-pub(super) fn truncate_with_ellipsis(s: &str, max_width: usize) -> String {
-    if max_width == 0 {
-        return String::new();
-    }
-    if s.width() <= max_width {
-        return s.to_string();
-    }
-    if max_width == 1 {
-        return "…".to_string();
-    }
-    let mut out = String::new();
-    let mut width = 0usize;
-    for c in s.chars() {
-        let cw = unicode_width::UnicodeWidthChar::width(c).unwrap_or(0);
-        if width + cw > max_width - 1 {
-            break;
-        }
-        out.push(c);
-        width += cw;
-    }
-    out.push('…');
-    out
-}
@@ -0,0 +1,109 @@
+use std::io::{self, Stdout, Write};
+
+use ratatui::Terminal;
+use ratatui::backend::CrosstermBackend;
+use ratatui::{TerminalOptions, Viewport};
+
+pub(crate) type InlineTerminal = Terminal<CrosstermBackend<Stdout>>;
+
+struct InlineTerminalGuard {
+    terminal: InlineTerminal,
+    closed: bool,
+}
+
+impl InlineTerminalGuard {
+    fn open(height: u16) -> io::Result<Self> {
+        let terminal = Terminal::with_options(
+            CrosstermBackend::new(io::stdout()),
+            TerminalOptions {
+                viewport: Viewport::Inline(height),
+            },
+        )?;
+        Ok(Self {
+            terminal,
+            closed: false,
+        })
+    }
+
+    fn close(&mut self) -> io::Result<()> {
+        if self.closed {
+            return Ok(());
+        }
+        self.closed = true;
+
+        let area = self.terminal.get_frame().area();
+        let last_row = area.bottom().saturating_sub(1);
+        let cursor_result = self.terminal.set_cursor_position((0, last_row));
+        let output_result = write_viewport_terminator(&mut io::stdout());
+        cursor_result?;
+        output_result
+    }
+}
+
+impl Drop for InlineTerminalGuard {
+    fn drop(&mut self) {
+        let _ = self.close();
+    }
+}
+
+pub(crate) fn with_inline_terminal<T, E>(
+    height: u16,
+    run: impl FnOnce(&mut InlineTerminal) -> Result<T, E>,
+) -> Result<T, E>
+where
+    E: From<io::Error>,
+{
+    let mut guard = InlineTerminalGuard::open(height).map_err(E::from)?;
+    let result = run(&mut guard.terminal);
+    let close_result = guard.close();
+    match result {
+        Ok(value) => {
+            close_result.map_err(E::from)?;
+            Ok(value)
+        }
+        Err(error) => Err(error),
+    }
+}
+
+fn write_viewport_terminator(output: &mut impl Write) -> io::Result<()> {
+    output.write_all(b"\r\n")?;
+    output.flush()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn viewport_terminator_moves_following_output_to_a_fresh_line() {
+        let mut output = Vec::new();
+
+        write_viewport_terminator(&mut output).unwrap();
+
+        assert_eq!(output, b"\r\n");
+    }
+
+    #[test]
+    fn inline_viewport_construction_is_owned_by_this_module() {
+        fn assert_shared_owner(path: &std::path::Path) {
+            for entry in std::fs::read_dir(path).unwrap() {
+                let path = entry.unwrap().path();
+                if path.is_dir() {
+                    assert_shared_owner(&path);
+                } else if path.extension().and_then(|value| value.to_str()) == Some("rs")
+                    && path.file_name().and_then(|value| value.to_str())
+                        != Some("inline_terminal.rs")
+                {
+                    let source = std::fs::read_to_string(&path).unwrap();
+                    assert!(
+                        !source.contains("Viewport::Inline"),
+                        "{} constructs an inline viewport outside its shared owner",
+                        path.display()
+                    );
+                }
+            }
+        }
+
+        assert_shared_owner(&std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("src"));
+    }
+}
--- a/Show More
+++ b/Show More