fix: validate resolved ancestry inside atomic projection dispatch

Resolve one connected lineage and retain its root-to-parent capabilities. Backends validate ancestor identity/membership and refresh all policy metadata inside the same boundary as target validators and typed dispatch; hidden/replaced ancestors reject as NotFound without invocation or effects. Preserve pinned leaf and configured-root capabilities. Covers MR ANCESTOR_VISIBILITY_TOCTOU with HTTP memory and Linux replacement/budget/guard regressions; all T-19 workspace acceptance commands pass (Clippy via Nix shell).

CHANGELOG.md

@@ -0,0 +1,16 @@
+# Changelog
+
+All notable changes to the published WIP Rust crates are documented here.
+
+## 0.1.0
+
+Initial public release of:
+
+- `wip-protocol`: transport-independent WIP logical model and validation.
+- `wip-interface-macros`: procedural-macro implementation for interface and DTO declarations.
+- `wip-interface`: public Rust interface-authoring facade and typed value codecs.
+- `wip-host`: request-scoped publication, precondition validation, and qualified operation dispatch.
+- `wip-http`: framework-independent WIP over HTTP v1 routes, strict JSON codecs, and failure classification.
+- `wip-client`: stateful Known Space, interest-driven acquisition, request ownership, and operation lifecycle.
+
+The repository also contains non-published filesystem server, terminal client, and public-API conformance packages.

Cargo.lock

@@ -1341,9 +1341,9 @@ dependencies = [
 
 [[package]]
 name = "yoke-derive"
-version = "0.8.3"
+version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33811428bee40dbceb6d545e95754741d17a6aef9a4849f0fd62e2ba4f412a78"
+checksum = "ec8ebde2db3681e8c9980cc27822030e68752690ddfa9473e739aeb4dbde6d71"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -1,3 +1,19 @@
 [workspace]
 members = ["crates/*"]
 resolver = "3"
+
+[workspace.package]
+version = "0.1.0"
+edition = "2024"
+rust-version = "1.88"
+license = "MIT OR Apache-2.0"
+repository = "https://gitea.hareworks.net/Hare/wip-rs"
+
+[workspace.dependencies]
+wip-client = { version = "0.1.0", path = "crates/wip-client" }
+wip-fs-server = { version = "0.1.0", path = "crates/wip-fs-server" }
+wip-host = { version = "0.1.0", path = "crates/wip-host" }
+wip-http = { version = "0.1.0", path = "crates/wip-http" }
+wip-interface = { version = "0.1.0", path = "crates/wip-interface" }
+wip-interface-macros = { version = "0.1.0", path = "crates/wip-interface-macros" }
+wip-protocol = { version = "0.1.0", path = "crates/wip-protocol" }

LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -13,43 +13,65 @@ repository root is not itself a package.
 ## Crate graph and responsibilities
 
 ```text
-wip-tui (interactive Worldspace explorer and operation editor)
+Published libraries
-├── wip-client                Known Space, request identity, validators, and calls
-├── wip-http                 framework-neutral HTTP request/response messages
-└── wip-protocol              descriptors and logical values
 
-wip-fs-server (request-time filesystem projection and loopback listener)
+wip-client
-├── wip-http                 standard routes/codecs/envelopes/batching
+├── wip-http
-├── wip-host                  request-scoped publication and dispatch
+│   └── wip-protocol
-└── wip-interface             macro-generated filesystem capabilities
+└── wip-protocol
 
-wip-public-api-example (workspace-only executable, integration tests, doctest)
+wip-host
-├── wip-protocol              logical declarations, values, calls, and validation
+├── wip-interface
-├── wip-http                 standard HTTP v1 routes, JSON codecs, envelopes, and batching
+│   ├── wip-interface-macros
 │   └── wip-protocol
-├── wip-client                stateful Known Space, lazy tree, observation, and call runtime
+└── wip-protocol
-│   ├── wip-http
+
-│   └── wip-protocol
+Workspace-only applications and conformance consumers
-├── wip-interface             application DTO codecs and interface authoring facade
+
-│   ├── wip-protocol
+wip-tui
-│   └── wip-interface-macros  proc-macro implementation detail
+├── wip-client
-└── wip-host                  descriptor registry, publication, and qualified dispatch
+├── wip-http
-    ├── wip-interface
+└── wip-protocol
-    └── wip-protocol
+
+wip-fs-server
+├── wip-host
+├── wip-http
+├── wip-interface
+└── wip-protocol
+
+wip-public-api-example
+├── wip-host
+├── wip-interface
+└── wip-protocol
 ```
 
 | Crate | Responsibility | Does not own |
 | --- | --- | --- |
 | `wip-protocol` | Transport-independent descriptors, object/call/result types, logical `Value`s, validation, and stable protocol error categories. | Application DTOs, implementations, persistence, or wire encoding. |
-| `wip-http` | Standard WIP over HTTP v1 endpoint/route derivation, UTF-8 JSON codecs, direct success bodies, error/status classification, and retrieval batches. | HTTP I/O, URL scheme or TLS policy, authentication schemes, server frameworks, filesystem projection, or client presentation/cache policy. |
+| `wip-http` | Standard WIP over HTTP v1 endpoint/route derivation, UTF-8 JSON codecs, direct success bodies, and error/status classification. | HTTP I/O, URL scheme or TLS policy, authentication schemes, server frameworks, filesystem projection, or client presentation/cache policy. |
 | `wip-client` | Endpoint/security-context-isolated Known Space, normalized object and interface observations, intent-driven object and descriptor coverage with bounded request deduplication, immutable operation call contexts, stale transitions, and bounded histories. | HTTP I/O, credentials, persistent cache, automatic operation retries, or presentation widgets/events. |
 | `wip-tui` | Keyboard-only interactive Worldspace tree, selected Entry and qualified operation panes, descriptor-driven argument editing, bounded result/diagnostic rendering, terminal lifecycle, and HTTP I/O workers over `wip-client`. | Independent cache/validator semantics, automatic operation retries, Host internals, backend paths, or persistent state. |
 | `wip-interface` | The public `WipType`/`interface` authoring API, Rust-to-protocol codecs, generated descriptors, and typed implementation dispatch. | Object publication, backend lifetime, or transport policy. |
 | `wip-interface-macros` | Procedural-macro expansion used by `wip-interface`. It is not an application dependency. | A supported direct user API. |
 | `wip-host` | Opaque interface registration, explicit object membership, validator checks, interface-qualified dispatch against one host-owned instance, and descriptor-guided argument decoding inside that same resolution boundary. | Backend atomicity, global object lookup, or network serving. |
-| `wip-fs-server` | Linux directory-handle-confined request-time projection, complete depth-bounded observations and bounded file operations, standard `wip-http` dispatch/batch handling, and a loopback HTTP binary. | A new wire profile, implicit symlink following, non-loopback cleartext, authentication policy, TLS termination, or filesystem-wide preregistration. |
+| `wip-fs-server` | Linux directory-handle-confined request-time projection, complete depth-bounded observations and bounded file operations, standard `wip-http` dispatch, and a loopback HTTP binary. | A new wire profile, implicit symlink following, non-loopback cleartext, authentication policy, TLS termination, or filesystem-wide preregistration. |
 | `wip-public-api-example` | An independently compiled consumer of the protocol, authoring, and host public crates. Its DTOs and traits are application-owned; its implementation and backend handle remain host-private. | Reusable library API or a production server. |
 
+## Published crates
+
+The `0.1.0` release consists of these six crates:
+
+- `wip-protocol`
+- `wip-interface-macros` — implementation dependency re-exported by `wip-interface`
+- `wip-interface`
+- `wip-host`
+- `wip-http`
+- `wip-client`
+
+The filesystem server, terminal client, and public-API example are workspace-only packages and set `publish = false`. All workspace packages require Rust 1.88 or newer and are licensed under either Apache-2.0 or MIT at your option.
+
+See [RELEASING.md](RELEASING.md) for the dependency-ordered crates.io procedure and [CHANGELOG.md](CHANGELOG.md) for release contents.
+
 The boundary is intentional: protocol types describe what can cross a
 transport; application DTOs opt into that model with `WipType`; a host-private
 implementation owns credentials, handles, and backend state; and `wip-http`

RELEASING.md

@@ -0,0 +1,75 @@
+# Releasing
+
+The six crates published from this workspace use one version and must be released in dependency order. The filesystem server, terminal client, and public-API example set `publish = false` and are never uploaded.
+
+## Preconditions
+
+1. Work from a clean `master` whose `HEAD` matches `origin/master`.
+2. Confirm the intended version in `[workspace.package]` and every internal requirement in `[workspace.dependencies]`.
+3. Confirm ownership of all six names on crates.io.
+4. Run the complete repository validation suite:
+
+```console
+cargo fmt --all -- --check
+cargo check --workspace --all-targets
+cargo test --workspace --all-targets
+cargo test --workspace --doc
+cargo clippy --workspace --all-targets -- -D warnings
+RUSTDOCFLAGS='-D warnings' cargo doc --workspace --no-deps
+cargo run --package wip-public-api-example
+git diff --check
+```
+
+## Publish order
+
+Before uploading anything, dry-run the exact public package set together. Cargo uses a temporary local registry for unpublished workspace dependencies during this check:
+
+```console
+cargo publish --dry-run --workspace \
+  --exclude wip-fs-server \
+  --exclude wip-public-api-example \
+  --exclude wip-tui
+```
+
+Then dry-run and publish each layer before moving to a crate that depends on it:
+
+```console
+cargo publish --dry-run --package wip-protocol
+cargo publish --package wip-protocol
+
+cargo publish --dry-run --package wip-interface-macros
+cargo publish --package wip-interface-macros
+```
+
+Wait until both versions are available from the crates.io index, then continue:
+
+```console
+cargo publish --dry-run --package wip-interface
+cargo publish --package wip-interface
+
+cargo publish --dry-run --package wip-http
+cargo publish --package wip-http
+```
+
+After those versions are available from the index:
+
+```console
+cargo publish --dry-run --package wip-host
+cargo publish --package wip-host
+
+cargo publish --dry-run --package wip-client
+cargo publish --package wip-client
+```
+
+Registry propagation can take time. A dependent dry-run reporting that a WIP crate is unavailable means the previous publish is not visible in the selected registry yet; do not bypass verification.
+
+## Tag
+
+After all six uploads resolve successfully, tag the exact published commit and push the tag:
+
+```console
+git tag -a v0.1.0 -m "release: 0.1.0"
+git push origin v0.1.0
+```
+
+Do not move or recreate a published version or its tag. Prepare a new version for any subsequent correction.

crates/wip-client/Cargo.toml

@@ -1,10 +1,14 @@
 [package]
 name = "wip-client"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Presentation-independent stateful WIP client runtime"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-client"
 
 [dependencies]
-wip-http = { path = "../wip-http" }
+wip-http.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true

crates/wip-client/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
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+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
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+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
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+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
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+
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+
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+   See the License for the specific language governing permissions and
+   limitations under the License.

crates/wip-client/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-client/README.md

@@ -0,0 +1,16 @@
+# wip-client
+
+Presentation-independent stateful runtime for Web Interface Protocol (WIP) clients.
+
+`wip-client` manages endpoint- and security-context-isolated Known Space, object and Interface Descriptor observations, bounded request ownership, supersession, out-of-order response suppression, validator recovery, and operation call contexts. It produces and consumes framework-neutral `wip-http` messages but performs no network I/O and contains no UI types.
+
+```toml
+[dependencies]
+wip-client = "0.1.0"
+```
+
+Applications provide the HTTP adapter and presentation layer, send each prepared request exactly as owned by the runtime, then return the corresponding response for completion.
+
+See the [API documentation](https://docs.rs/wip-client) for session, acquisition, cache, and call APIs.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-client/tests/adapter.rs

@@ -16,7 +16,7 @@ use wip_protocol::{
 };
 
 fn limits() -> Limits {
-    Limits::new(64 * 1024, 64 * 1024, 64, 64).unwrap()
+    Limits::new(64 * 1024, 64 * 1024, 64).unwrap()
 }
 
 fn setup() -> (Client, wip_client::SessionId) {
@@ -145,16 +145,37 @@ fn valid_error_envelope_is_authoritative_and_status_mismatch_is_diagnostic() {
 }
 
 #[test]
-fn non_success_without_valid_envelope_remains_transport_failure() {
+fn resource_envelope_on_413_uses_code_and_records_canonical_422_mismatch() {
     let (mut client, session) = setup();
     let request = client.refresh_observed(&session, "/item", 0).unwrap();
-    let error = client
+    let error = ProtocolError {
-        .complete(
+        code: ProtocolErrorCode::ResourceLimitExceeded,
-            request.id,
+        message: "logical observation limit exceeded".into(),
-            response(StatusCode::BAD_GATEWAY, b"gateway html"),
+    };
-        )
+    let mut encoded =
-        .unwrap_err();
+        encode_protocol_error_response(ProtocolInteraction::Observe, &error, limits()).unwrap();
-    assert_eq!(error.kind, ClientErrorKind::Transport);
+    *encoded.status_mut() = StatusCode::PAYLOAD_TOO_LARGE;
+
+    assert_eq!(
+        client.complete(request.id, encoded).unwrap(),
+        Completion::ProtocolFailure(error)
+    );
+    assert_eq!(
+        client.diagnostics(&session).unwrap().back().unwrap().kind,
+        DiagnosticKind::HttpStatusMismatch
+    );
+}
+
+#[test]
+fn non_success_without_valid_envelope_remains_transport_failure() {
+    for status in [StatusCode::BAD_GATEWAY, StatusCode::PAYLOAD_TOO_LARGE] {
+        let (mut client, session) = setup();
+        let request = client.refresh_observed(&session, "/item", 0).unwrap();
+        let error = client
+            .complete(request.id, response(status, b"infrastructure failure"))
+            .unwrap_err();
+        assert_eq!(error.kind, ClientErrorKind::Transport);
+    }
 }
 
 #[test]
@@ -250,3 +271,80 @@ fn malformed_call_success_after_dispatch_is_outcome_unknown_and_stales_object()
     );
     assert_eq!(client.in_flight_len(), 0);
 }
+
+#[test]
+fn plain_413_after_call_dispatch_is_unknown_transport_outcome() {
+    let (mut client, session) = setup();
+    let observation = client.refresh_observed(&session, "/item", 0).unwrap();
+    client
+        .complete(
+            observation.id,
+            encode_observe_response(
+                &ObserveRequest {
+                    path: "/item".into(),
+                    depth: 0,
+                },
+                &ObjectObservation {
+                    object: object(),
+                    children: None,
+                },
+                limits(),
+            )
+            .unwrap(),
+        )
+        .unwrap();
+    let interface = client.prepare_interface(&session, "math").unwrap();
+    client
+        .complete(
+            interface.id,
+            encode_fetch_interface_response(
+                &FetchInterfaceRequest {
+                    interface: "math".into(),
+                },
+                &FetchInterfaceResponse {
+                    interface: "math".into(),
+                    descriptor: descriptor(INTERFACE_FORMAT_V1),
+                    validator: None,
+                },
+                limits(),
+            )
+            .unwrap(),
+        )
+        .unwrap();
+    let call = client
+        .prepare_call(
+            &session,
+            "/item",
+            "math",
+            "calculate",
+            BTreeMap::from([("value".into(), Value::Integer(2))]),
+        )
+        .unwrap();
+    client.mark_dispatched(call.id).unwrap();
+
+    let completion = client
+        .complete(
+            call.id,
+            Response::builder()
+                .status(StatusCode::PAYLOAD_TOO_LARGE)
+                .body(Vec::<u8>::new())
+                .unwrap(),
+        )
+        .unwrap();
+    assert!(matches!(
+        completion,
+        Completion::Call(record)
+            if matches!(
+                &record.outcome,
+                CallOutcome::Unknown {
+                    reason: OutcomeUnknownReason::ResponseDecode,
+                    failure: Some(failure),
+                } if failure.kind == ClientErrorKind::Transport
+            )
+    ));
+    assert_eq!(
+        client.object(&session, "/item").unwrap().state,
+        ObservationState::Stale
+    );
+    assert_eq!(client.in_flight_len(), 0);
+}

crates/wip-client/tests/runtime.rs

@@ -17,7 +17,7 @@ use wip_protocol::{
 };
 
 fn wire_limits() -> Limits {
-    Limits::new(64 * 1024, 64 * 1024, 64, 64).unwrap()
+    Limits::new(64 * 1024, 64 * 1024, 64).unwrap()
 }
 
 #[derive(Clone)]
@@ -399,6 +399,67 @@ fn ensure_interface_waits_for_request_and_cache_capacity_without_evicting() {
     ));
 }
 
+#[test]
+fn independent_retrievals_run_concurrently_and_complete_out_of_order() {
+    let mut client = client(8, 8, 8, 8);
+    let session = client
+        .open_session("https://example.test/wip", SecurityContext::new("subject"))
+        .unwrap();
+
+    let first = client.refresh_observed(&session, "/one", 0).unwrap();
+    let second = client.refresh_observed(&session, "/two", 0).unwrap();
+    let interface = client.prepare_interface(&session, "math").unwrap();
+
+    assert_eq!(first.request.uri().path(), "/wip/v1/observe");
+    assert_eq!(second.request.uri().path(), "/wip/v1/observe");
+    assert_eq!(interface.request.uri().path(), "/wip/v1/fetch_interface");
+    assert_eq!(client.in_flight_len(), 3);
+
+    client
+        .complete(
+            second.id,
+            observation_response("/two", &object("two", None, b"two")),
+        )
+        .unwrap();
+    client
+        .complete(
+            interface.id,
+            encode_fetch_interface_response(
+                &FetchInterfaceRequest {
+                    interface: "math".into(),
+                },
+                &FetchInterfaceResponse {
+                    interface: "math".into(),
+                    descriptor: descriptor(TypeExpr::Integer),
+                    validator: Some(b"math-v1".to_vec()),
+                },
+                wire_limits(),
+            )
+            .unwrap(),
+        )
+        .unwrap();
+    client
+        .complete(
+            first.id,
+            observation_response("/one", &object("one", None, b"one")),
+        )
+        .unwrap();
+
+    assert_eq!(
+        client.object(&session, "/one").unwrap().state,
+        ObservationState::Fresh
+    );
+    assert_eq!(
+        client.object(&session, "/two").unwrap().state,
+        ObservationState::Fresh
+    );
+    assert_eq!(
+        client.interface(&session, "math").unwrap().state,
+        ObservationState::Fresh
+    );
+    assert_eq!(client.in_flight_len(), 0);
+}
+
 #[test]
 fn newer_refresh_rejects_out_of_order_response_for_the_same_subject() {
     let mut client = client(8, 8, 8, 8);

crates/wip-fs-server/Cargo.toml

@@ -1,19 +1,21 @@
 [package]
 name = "wip-fs-server"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
-description = "Request-time filesystem projection server for WIP over HTTP"
+rust-version.workspace = true
-license = "MIT OR Apache-2.0"
+description = "Extensible request-time filesystem projection library and WIP over HTTP server"
+license.workspace = true
+repository.workspace = true
 readme = "README.md"
 publish = false
 
 [dependencies]
 http = "1"
 rustix = { version = "1.1", features = ["fs"] }
-wip-host = { path = "../wip-host" }
+wip-host.workspace = true
-wip-http = { path = "../wip-http" }
+wip-http.workspace = true
-wip-interface = { path = "../wip-interface" }
+wip-interface.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true
 
 [dev-dependencies]
 tempfile = "3"

crates/wip-fs-server/README.md

@@ -4,7 +4,120 @@
 Worldspace `/` at request time. It does not register the filesystem contents or
 keep one object instance per entry. It uses `wip-host` for publication and typed
 operation dispatch and uses the standard `wip-http` routes, JSON codecs,
-envelopes, batching, and HTTP status mapping.
+envelopes, and HTTP status mapping.
+
+## Library assembly and migration
+
+The existing `ServerConfig`, `WipFsServer::new`, `handle_http`, CLI flags and wire
+representation remain compatible. The formerly private projection has become a
+public, generic library engine. No package version or publication policy changes
+are required.
+
+Use `default_projection(root, access, limits)` to obtain the default Linux engine
+without starting a listener. `projection.view(&principal)` is the effective view;
+it owns canonical `observe` and `fetch_interface` and implements the standard
+`wip_host::ObjectProvider` typed `call_operation` API. `DefaultPolicy` has the unit
+principal `()`; default engines also offer unit-principal convenience methods.
+
+For an external backend/composition:
+
+1. Implement `BackendEntry` on a local, cloneable, root-confined stable capability.
+   Its `WipObject` metadata is public-only; its validator binds identity and the
+   protected state. Implement `FilesystemBackend` to resolve one connected
+   `ResolvedEntry<Entry>` (root-to-parent ancestry plus pinned target), enumerate
+   bounded children, and execute against that already-resolved lineage.
+2. Register generated `#[wip_interface::interface]` definitions using the existing
+   `wip_host::InterfaceRegistry`. `DefaultInterfaces::register` optionally supplies
+   reusable built-in tokens; using those tokens does not force their publication.
+3. Implement `Composition<Entry>` on a local type. Its local Object wraps the entry
+   and implements both `WipObject` and the chosen generated traits, avoiding orphan
+   rules. `PublishedObject::expose` proves each implementation at compile time.
+   Publication can add, replace, reorder or omit built-ins based on entry metadata
+   and actual backend capabilities, not just entry kind. `LinuxEntry` implements
+   bounded `FileRead`, `FileWrite` and `SymlinkInspect` for safe delegation; never
+   advertise write in read-only mode or link operations on a non-link capability.
+4. Assemble `Projection::new(backend, registry, composition, policy, limits)`.
+   `ProjectionPolicy` supplies an opaque associated `Principal`, hides Objects and
+   entire hidden subtrees, selects an ordered subset of implemented interfaces,
+   controls descriptor/operation visibility, and permits or denies execution.
+5. An authenticated deployment chooses the principal and `ExecutionContext`. To
+   use HTTP, construct `HttpAdapter::new(&view, &endpoint, limits)` and invoke
+   `handle_http_with_context`. This uses the standard `wip-http` binding, not a
+   filesystem wire profile. Enforce body collection, header, concurrency and
+   deadline bounds in the deployment's listener; the adapter owns none of these
+   intake resources. The bundled loopback listener remains a thin default user.
+
+A complete external-style memory backend, local Object with multiple custom
+Operations, typed registration, principal policy and HTTP flow is exercised in
+[`tests/extensions.rs`](tests/extensions.rs). It uses no Linux filesystem for its
+backend. The public library APIs do not require private types, a fork, an HTTP
+listener, a global object registry, or dynamic plugin loading.
+
+### Extension security contract
+
+Backend implementations and Operation authors are trusted code, not sandboxed
+plugins. `FilesystemBackend::resolve` returns `ResolvedEntry::new(ancestors, target)`
+from one connected backend traversal/snapshot, not independent path-prefix
+resolutions. A root target has no ancestors; other targets retain the root first,
+then intermediate parent containers. This is backend-private context, never wire
+metadata. Backend `resolve` and `execute` signatures both carry this type;
+compositions still receive only the exact scoped target `Entry`.
+
+`FilesystemBackend::execute` must validate ancestor membership/identity and
+refresh **all** lineage state/validators inside its transaction or lock before
+calling the engine callback, retaining the same target and connected ancestry
+through validation and dispatch. Replaced/detached ancestors must return
+`NotFound` without callback invocation, even when the replacement is visible.
+The engine evaluates Object visibility for every refreshed ancestor and target
+inside that same boundary; a hidden ancestor rejects the entire subtree before
+publication/typed dispatch. Never fix a changed lineage by resolving the raw path
+again and substituting capabilities. Participating policy-relevant backend state
+changes must be serialized by this boundary, not just target-content writes.
+Return the committed post-operation validator. Retained ancestry is subject to
+handle/work ceilings; resource exhaustion is an error, not missing ancestry.
+Confirm rollback only after rollback succeeds. Pre-dispatch failures
+must never commit; failed started operations without a non-commit guarantee remain
+`OperationOutcomeUnknown`. Object implementations must delegate validators to
+that entry and declare requirements per `(InterfaceRef, operation)`, rather than
+classify all operations by a read/write name. Operations use the scoped entry and
+propagated context, not a fresh raw-path resolution; they must check deadlines,
+cancellation and resource budgets throughout backend work and report effects
+truthfully. POSIX symlinks, identity, atomic mutations and locking cannot be assumed
+for other backends.
+
+The default Linux backend acquires advisory exclusive locks in root-to-parent
+order and then on the lockable target (directory or regular file). It compares
+retained ancestor identity to no-follow descriptor-relative lookup results,
+refreshes lineage snapshots after acquiring the locks, and holds the guards
+through post-dispatch state observation. The configured root remains its pinned
+capability even if its textual path is renamed; replaced intermediate ancestors
+are rejected. Leaf path replacement never redirects execution to a new inode.
+This serializes cooperating library calls; it does **not** promise transactional
+isolation from unrelated processes ignoring `flock`. Linux capabilities only
+expose bounded methods, not raw descriptors or backend paths.
+
+A policy must be stable/deterministic within one effective Worldspace view.
+Interface/operation visibility is uniform per registered reference within that
+view, so observation, fetch and dispatch use the identical filtered descriptor.
+For entry-specific operation sets, register distinct interface definitions and
+select them by entry. Different principals may have different effective views.
+Changing a policy must establish a new view/reference lifetime (e.g. rebuild the
+registry/engine); do not keep validator-free references while changing their
+meaning. Execution permission may deny a visible Operation without hiding it.
+A published interface is always fetchable by that principal; hidden operations
+are omitted (along with their unreachable named types and interface-wide docs)
+and guessed calls return `OperationNotFound`, whereas visible denied
+operations return `PermissionDenied`. Hidden Objects and descendants return
+`NotFound` and are absent from parent observations. Work spent scanning hidden
+entries still counts against traversal bounds; resource limits are not a
+constant-time/side-channel guarantee.
+
+Never put absolute paths, hidden metadata, credentials or policy internals in
+public `WipObject` metadata, descriptions, validators or normal logs. Validators
+must be opaque public tokens, not confidential content. Engine/HTTP failures use
+bounded generic diagnostics; arbitrary trusted implementation metadata/logging
+cannot be sanitized automatically. Do not log credentials or sensitive panic
+payloads from extensions.
 
 ## Security model
 
@@ -118,14 +231,11 @@ curl -sS -X POST http://127.0.0.1:8080/wip/v1/call_operation \
   }'
 ```
 
-`observe` and `fetch_interface` can also be combined through the standard
-`POST /wip/v1/batch` route. `call_operation` is never batchable.
-
 ## Resource and failure behavior
 
 `ResourceLimits` bounds request/response bytes, HTTP request-head bytes, JSON
-nesting, batch items, file read/write bytes, tree depth/node count, pinned handles,
+nesting, file read/write bytes, tree depth/node count, pinned handles, and active
-and active connections/requests. One absolute request deadline covers header and
+connections/requests. One absolute request deadline covers header and
 body intake, dispatch, cooperative filesystem work, and response transmission;
 stalled clients are closed and cannot occupy a worker beyond that bound. Workers
 accept connections directly, so the listener never moves more than the configured

crates/wip-fs-server/src/defaults.rs

@@ -0,0 +1,146 @@
+//! Reusable default Linux composition; no listener or authentication dependency.
+use crate::engine::{BackendEntry, Composition, DefaultPolicy, EntryKind, Projection};
+use crate::interfaces::{
+    FileRead, FileReadDefinition, FileWrite, FileWriteDefinition, SymlinkInspect,
+    SymlinkInspectDefinition,
+};
+use crate::projection::{LinuxBackend, LinuxEntry};
+use crate::{AccessMode, ResourceLimits};
+use wip_host::{
+    ExecutionContext, HostError, InterfaceRef, InterfaceRegistry, PublishedObject,
+    RegisteredInterface, RegistrationError, Validator, WipObject,
+};
+use wip_interface as wip;
+
+/// Registered built-in interfaces, usable by external compositions and Objects.
+pub struct DefaultInterfaces {
+    /// Bounded regular-file reads.
+    pub read: RegisteredInterface<FileReadDefinition>,
+    /// No-follow link inspection.
+    pub symlink: RegisteredInterface<SymlinkInspectDefinition>,
+    /// Validator-protected replacement.
+    pub write: RegisteredInterface<FileWriteDefinition>,
+}
+impl DefaultInterfaces {
+    /// Register reusable default descriptors without publishing any objects.
+    pub fn register(registry: &mut InterfaceRegistry) -> Result<Self, RegistrationError> {
+        Ok(Self {
+            read: registry.register(FileReadDefinition, None)?,
+            symlink: registry.register(SymlinkInspectDefinition, None)?,
+            write: registry.register(FileWriteDefinition, None)?,
+        })
+    }
+}
+
+/// Default capability-aware Linux publication, independent of HTTP.
+pub struct DefaultComposition {
+    interfaces: DefaultInterfaces,
+}
+impl DefaultComposition {
+    /// Use previously registered built-in interface tokens.
+    pub fn new(interfaces: DefaultInterfaces) -> Self {
+        Self { interfaces }
+    }
+}
+
+/// Request-scoped default Object; external Objects may instead wrap `LinuxEntry`.
+pub struct DefaultObject {
+    entry: LinuxEntry,
+    write: InterfaceRef,
+}
+impl DefaultObject {
+    /// The pinned, bounded capability used by every operation on this Object.
+    pub fn entry(&self) -> &LinuxEntry {
+        &self.entry
+    }
+}
+impl WipObject for DefaultObject {
+    fn name(&self) -> &str {
+        self.entry.name()
+    }
+    fn description(&self) -> Option<&str> {
+        self.entry.description()
+    }
+    fn reference(&self) -> Option<&str> {
+        self.entry.reference()
+    }
+    fn validator(&self) -> Option<&Validator> {
+        self.entry.validator()
+    }
+    fn requires_validator(&self, interface: &InterfaceRef, operation: &str) -> bool {
+        interface == &self.write && operation == "replace"
+    }
+}
+impl FileRead for DefaultObject {
+    fn read(&self, offset: Option<u64>, length: Option<u64>) -> wip::OperationResult<wip::Bytes> {
+        self.entry.read(offset, length)
+    }
+}
+impl SymlinkInspect for DefaultObject {
+    fn read_link(&self) -> wip::OperationResult<wip::Bytes> {
+        self.entry.read_link()
+    }
+}
+impl FileWrite for DefaultObject {
+    fn replace(&self, contents: wip::Bytes) -> wip::OperationResult<()> {
+        self.entry.replace(contents)
+    }
+}
+impl Composition<LinuxEntry> for DefaultComposition {
+    type Object = DefaultObject;
+    fn publish(
+        &self,
+        entry: LinuxEntry,
+        _: &ExecutionContext,
+    ) -> Result<PublishedObject<Self::Object>, HostError> {
+        let kind = entry.kind();
+        let writable = entry.access_mode() == AccessMode::ReadWrite;
+        let mut publication = PublishedObject::new(DefaultObject {
+            entry,
+            write: self.interfaces.write.reference().clone(),
+        });
+        match kind {
+            EntryKind::Regular => {
+                publication = publication
+                    .expose(&self.interfaces.read)
+                    .map_err(publication_error)?;
+                if writable {
+                    publication = publication
+                        .expose(&self.interfaces.write)
+                        .map_err(publication_error)?;
+                }
+            }
+            EntryKind::Symlink => {
+                publication = publication
+                    .expose(&self.interfaces.symlink)
+                    .map_err(publication_error)?;
+            }
+            EntryKind::Directory | EntryKind::Unsupported => {}
+        }
+        Ok(publication)
+    }
+}
+fn publication_error(_: wip_host::PublicationError) -> HostError {
+    HostError::internal(
+        "default publication failed",
+        wip_host::EffectGuarantee::NotCommitted,
+    )
+}
+
+/// Construct the secure-by-default Linux engine without binding a listener.
+pub fn default_projection(
+    root: &std::path::Path,
+    access: AccessMode,
+    limits: ResourceLimits,
+) -> Result<Projection<LinuxBackend, DefaultComposition, DefaultPolicy>, std::io::Error> {
+    let backend = LinuxBackend::open(root, access, limits)?;
+    let mut registry = InterfaceRegistry::new();
+    let interfaces = DefaultInterfaces::register(&mut registry).map_err(std::io::Error::other)?;
+    Ok(Projection::new(
+        backend,
+        registry,
+        DefaultComposition::new(interfaces),
+        DefaultPolicy,
+        limits,
+    ))
+}

crates/wip-fs-server/src/engine.rs

@@ -0,0 +1,661 @@
+//! Transport-independent projection, publication, and principal view boundaries.
+
+use crate::ResourceLimits;
+use wip_host::{
+    EffectGuarantee, ExecutionContext, HostError, InterfaceRef, InterfaceRegistry, ObjectProvider,
+    OperationAttempt, ProviderResult, PublishedObject, WipObject,
+};
+use wip_protocol::{
+    FetchInterfaceRequest, FetchInterfaceResponse, ObjectObservation, ObserveRequest,
+    ObserveResponse, ProtocolError, ProtocolErrorCode,
+};
+
+/// Portable entry classification; capabilities must not be inferred from kind alone.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EntryKind {
+    /// Container whose children can be enumerated.
+    Directory,
+    /// Regular data entry.
+    Regular,
+    /// Link itself, never implicitly followed.
+    Symlink,
+    /// Metadata-only entry unless the composition supplies a capability.
+    Unsupported,
+}
+
+/// A root-confined, request-time capability, not a path to resolve again.
+///
+/// Metadata must be safe for public exposure. Validators bind both identity and
+/// protected state. Cloning must retain the same target rather than re-resolve it.
+pub trait BackendEntry: WipObject + Clone {
+    /// Classification for observation and publication selection.
+    fn kind(&self) -> EntryKind;
+}
+
+/// A single resolved target together with its retained root-to-parent lineage.
+///
+/// The backend must resolve a connected lineage, never independent raw-path
+/// prefixes. At execution it validates ancestor membership/identity, refreshes
+/// their policy metadata, and pins that snapshot through dispatch. Target
+/// replacement must not redirect the original capability. This value is private
+/// backend context, not protocol metadata.
+#[derive(Clone)]
+pub struct ResolvedEntry<E> {
+    ancestors: Vec<E>,
+    target: E,
+}
+
+impl<E> ResolvedEntry<E> {
+    /// Create backend resolution context. `/` has no ancestors; a non-root target
+    /// has the pinned root first, followed by its intermediate parent containers.
+    pub fn new(ancestors: Vec<E>, target: E) -> Self {
+        Self { ancestors, target }
+    }
+    /// Pinned ancestor capabilities, ordered from the root to the direct parent.
+    pub fn ancestors(&self) -> &[E] {
+        &self.ancestors
+    }
+    /// The original resolved target capability, never a redirected replacement.
+    pub fn target(&self) -> &E {
+        &self.target
+    }
+    /// Consume this snapshot for refresh or request-time publication.
+    pub fn into_parts(self) -> (Vec<E>, E) {
+        (self.ancestors, self.target)
+    }
+}
+
+/// Trusted backend boundary. Implementations need not use POSIX semantics.
+///
+/// Resolve and enumerate pinned capabilities within the configured root. Enforce
+/// context cancellation, deadlines and work budgets during backend work. Do not
+/// advertise capabilities the backend cannot guarantee. Errors must not include
+/// backend paths, credentials or hidden metadata.
+///
+/// `execute` must retain the same target and complete lineage and serialize
+/// ancestor identity/membership checks, policy metadata, validator observation,
+/// publication, validation, typed dispatch and commit/rollback. Changed/detached
+/// ancestors must return `NotFound` before the callback; never substitute a new
+/// ancestor or redirect the target by re-resolving its raw path. Refresh *all*
+/// lineage metadata/validators inside the boundary and retain that snapshot
+/// through dispatch, then return the committed post-operation validator. Never
+/// upgrade an unknown outcome except after confirmed rollback. Locks only protect
+/// actors participating in the protocol; document any external-writer limits.
+pub trait FilesystemBackend {
+    /// Stable capability supplied to the composition.
+    type Entry: BackendEntry;
+    /// Resolve a canonical WIP path and retain its connected ancestry.
+    ///
+    /// Obtain the target and lineage in one backend traversal/snapshot. Enforce
+    /// configured handle/work budgets while retaining ancestors; do not silently
+    /// omit ancestry on resource exhaustion.
+    fn resolve(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+    ) -> ProviderResult<ResolvedEntry<Self::Entry>>;
+    /// Enumerate direct children, at most `maximum`; excess must fail, not truncate.
+    fn children(
+        &self,
+        context: &ExecutionContext,
+        entry: &Self::Entry,
+        maximum: usize,
+    ) -> Result<Vec<Self::Entry>, HostError>;
+    /// Execute against this already-resolved target within an atomic boundary.
+    fn execute(
+        &self,
+        context: &ExecutionContext,
+        entry: ResolvedEntry<Self::Entry>,
+        operation: impl FnOnce(ResolvedEntry<Self::Entry>) -> OperationAttempt,
+    ) -> ProviderResult<OperationAttempt>;
+}
+
+/// Typed publication extension point, implementable on an external crate's type.
+///
+/// Use `InterfaceRegistry::register` and `PublishedObject::expose` with generated
+/// definitions. An external local Object can wrap the entry and implement any
+/// number of interfaces, avoiding orphan rules. Its `WipObject` implementation
+/// declares validator requirements per qualified operation. Operation failures
+/// declare their own `EffectGuarantee`, not a fixed read/write classification.
+pub trait Composition<E: BackendEntry> {
+    /// Local typed operation implementation and safe public metadata.
+    type Object: WipObject;
+    /// Build a request-scoped publication using this exact capability/context.
+    ///
+    /// Publication and policy hooks must be side-effect-free with respect to the
+    /// backend. A publication failure is a pre-dispatch rejection, never a
+    /// started Operation. Delegate metadata/validators to the boundary snapshot.
+    fn publish(
+        &self,
+        entry: E,
+        context: &ExecutionContext,
+    ) -> Result<PublishedObject<Self::Object>, HostError>;
+}
+
+/// Principal-specific view policy, independent of authentication transport.
+///
+/// Keep decisions deterministic and stable within an effective Worldspace view.
+/// A changed policy requires a new view/reference lifetime (or interface
+/// validators). Operation visibility is interface-wide within a view so every
+/// published reference has exactly the descriptor returned by fetch. Entry-
+/// specific differences should select different registered interfaces. Hooks
+/// cannot add implementations, metadata, or raw paths to a publication.
+pub trait ProjectionPolicy<E: BackendEntry, O: WipObject> {
+    /// Opaque deployment-established principal/request identity.
+    type Principal;
+    /// Whether the entry is visible. Invisible ancestors hide their whole subtree.
+    fn object_visible(&self, principal: &Self::Principal, entry: &E) -> bool;
+    /// Whether an interface descriptor may be fetched in this view.
+    fn interface_visible(&self, _principal: &Self::Principal, _interface: &InterfaceRef) -> bool {
+        true
+    }
+    /// Select/order a subset of implemented interfaces; defaults to all.
+    fn interfaces(
+        &self,
+        _principal: &Self::Principal,
+        _entry: &E,
+        available: &[InterfaceRef],
+    ) -> Vec<InterfaceRef> {
+        available.to_vec()
+    }
+    /// Whether an operation is present in this view's descriptor and dispatch.
+    fn operation_visible(
+        &self,
+        _principal: &Self::Principal,
+        _interface: &InterfaceRef,
+        _operation: &str,
+    ) -> bool {
+        true
+    }
+    /// Execution permission for a visible operation, after canonical preconditions.
+    fn authorize(
+        &self,
+        _principal: &Self::Principal,
+        _object: &O,
+        _interface: &InterfaceRef,
+        _operation: &str,
+    ) -> bool {
+        true
+    }
+}
+
+/// No authentication assumption: all configured objects/operations are visible.
+pub struct DefaultPolicy;
+impl<E: BackendEntry, O: WipObject> ProjectionPolicy<E, O> for DefaultPolicy {
+    type Principal = ();
+    fn object_visible(&self, _: &(), _: &E) -> bool {
+        true
+    }
+}
+
+/// Canonical request-time engine, independent of HTTP and Linux.
+pub struct Projection<B, C, P> {
+    backend: B,
+    registry: InterfaceRegistry,
+    composition: C,
+    policy: P,
+    limits: ResourceLimits,
+}
+
+impl<B, C, P> Projection<B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    /// Assemble trusted components. The registry must contain all exposed tokens.
+    pub fn new(
+        backend: B,
+        registry: InterfaceRegistry,
+        composition: C,
+        policy: P,
+        limits: ResourceLimits,
+    ) -> Self {
+        Self {
+            backend,
+            registry,
+            composition,
+            policy,
+            limits,
+        }
+    }
+    /// Backend access for trusted composition/configuration, never serialized.
+    pub fn backend(&self) -> &B {
+        &self.backend
+    }
+    /// Borrow one effective principal view for observation, fetch and dispatch.
+    pub fn view<'a>(&'a self, principal: &'a P::Principal) -> ProjectionView<'a, B, C, P> {
+        ProjectionView {
+            projection: self,
+            principal,
+        }
+    }
+}
+
+/// A coherent principal view implementing canonical typed host dispatch.
+pub struct ProjectionView<'a, B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    projection: &'a Projection<B, C, P>,
+    principal: &'a P::Principal,
+}
+
+impl<B, C, P> ProjectionView<'_, B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    fn resolve(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+    ) -> ProviderResult<ResolvedEntry<B::Entry>> {
+        if let Err(error) = preflight(context) {
+            return ProviderResult::Failure(error);
+        }
+        if wip_protocol::validate_path(path).is_err() {
+            return ProviderResult::NotFound;
+        }
+        match self.projection.backend.resolve(context, path) {
+            ProviderResult::Found(resolved) => {
+                if !lineage_matches_path(&resolved, path) {
+                    return ProviderResult::Failure(internal());
+                }
+                if !self.lineage_visible(&resolved) {
+                    return ProviderResult::NotFound;
+                }
+                ProviderResult::Found(resolved)
+            }
+            ProviderResult::NotFound => ProviderResult::NotFound,
+            ProviderResult::Failure(error) => ProviderResult::Failure(error),
+        }
+    }
+
+    fn lineage_visible(&self, resolved: &ResolvedEntry<B::Entry>) -> bool {
+        resolved
+            .ancestors()
+            .iter()
+            .chain(std::iter::once(resolved.target()))
+            .all(|entry| self.projection.policy.object_visible(self.principal, entry))
+    }
+
+    fn publication(
+        &self,
+        entry: B::Entry,
+        context: &ExecutionContext,
+    ) -> Result<PublishedObject<C::Object>, HostError> {
+        let publication = self
+            .projection
+            .composition
+            .publish(entry.clone(), context)?;
+        let available = publication
+            .protocol_object()
+            .interfaces
+            .iter()
+            .map(|reference| {
+                self.projection
+                    .registry
+                    .resolve(reference)
+                    .ok_or_else(internal)
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+        let mut selected = self
+            .projection
+            .policy
+            .interfaces(self.principal, &entry, &available);
+        selected.retain(|reference| {
+            self.projection
+                .policy
+                .interface_visible(self.principal, reference)
+        });
+        publication
+            .project(&selected, |reference, operation| {
+                self.projection
+                    .policy
+                    .operation_visible(self.principal, reference, operation)
+            })
+            .map_err(|_| internal())
+    }
+
+    /// Retrieve the descriptor with precisely this principal's visible operations.
+    pub fn fetch_interface(
+        &self,
+        request: &FetchInterfaceRequest,
+    ) -> Result<FetchInterfaceResponse, ProtocolError> {
+        read_boundary(|| self.fetch_interface_inner(request))
+    }
+
+    fn fetch_interface_inner(
+        &self,
+        request: &FetchInterfaceRequest,
+    ) -> Result<FetchInterfaceResponse, ProtocolError> {
+        let observation = self
+            .projection
+            .registry
+            .fetch_interface(&request.interface)?;
+        if !self
+            .projection
+            .policy
+            .interface_visible(self.principal, &observation.reference)
+        {
+            return Err(protocol(
+                ProtocolErrorCode::InterfaceNotFound,
+                "interface is not published",
+            ));
+        }
+        let reference = observation.reference.clone();
+        observation
+            .project_operations(|operation| {
+                self.projection
+                    .policy
+                    .operation_visible(self.principal, &reference, operation)
+            })
+            .protocol_response()
+    }
+
+    /// Observe a complete bounded tree, omitting invisible children and subtrees.
+    pub fn observe(
+        &self,
+        context: &ExecutionContext,
+        request: &ObserveRequest,
+    ) -> Result<ObserveResponse, ProtocolError> {
+        read_boundary(|| self.observe_inner(context, request))
+    }
+
+    fn observe_inner(
+        &self,
+        context: &ExecutionContext,
+        request: &ObserveRequest,
+    ) -> Result<ObserveResponse, ProtocolError> {
+        request
+            .validate()
+            .map_err(|_| protocol(ProtocolErrorCode::InvalidRequest, "invalid observe request"))?;
+        if request.depth > self.projection.limits.max_observation_depth {
+            return Err(resource_protocol());
+        }
+        let entry = match self.resolve(context, &request.path) {
+            ProviderResult::Found(entry) => entry,
+            ProviderResult::NotFound => {
+                return Err(protocol(
+                    ProtocolErrorCode::NotFound,
+                    "target path is not published",
+                ));
+            }
+            ProviderResult::Failure(error) => return Err(read_error(error)),
+        };
+        let (_ancestors, entry) = entry.into_parts();
+        let mut remaining = u64::from(self.projection.limits.max_observation_nodes)
+            .min(context.resource_budget().unwrap_or(u64::MAX));
+        let response = self.observe_entry(context, entry, request.depth, &mut remaining)?;
+        request.validate_response(&response).map_err(|_| {
+            protocol(
+                ProtocolErrorCode::Internal,
+                "invalid projection observation",
+            )
+        })?;
+        Ok(response)
+    }
+
+    fn observe_entry(
+        &self,
+        context: &ExecutionContext,
+        entry: B::Entry,
+        depth: u32,
+        remaining: &mut u64,
+    ) -> Result<ObjectObservation, ProtocolError> {
+        preflight(context).map_err(read_error)?;
+        if *remaining == 0 {
+            return Err(resource_protocol());
+        }
+        *remaining -= 1;
+        let object = self
+            .publication(entry.clone(), context)
+            .map_err(read_error)?
+            .protocol_object();
+        if depth == 0 {
+            return Ok(ObjectObservation {
+                object,
+                children: None,
+            });
+        }
+        let mut children = Vec::new();
+        if entry.kind() == EntryKind::Directory {
+            let entries = self
+                .projection
+                .backend
+                .children(
+                    context,
+                    &entry,
+                    usize::try_from(*remaining).unwrap_or(usize::MAX),
+                )
+                .map_err(read_error)?;
+            if entries.len() as u64 > *remaining {
+                return Err(resource_protocol());
+            }
+            for child in entries {
+                if self
+                    .projection
+                    .policy
+                    .object_visible(self.principal, &child)
+                {
+                    children.push(self.observe_entry(context, child, depth - 1, remaining)?);
+                } else {
+                    if *remaining == 0 {
+                        return Err(resource_protocol());
+                    }
+                    *remaining -= 1;
+                }
+            }
+        }
+        Ok(ObjectObservation {
+            object,
+            children: Some(children),
+        })
+    }
+}
+
+impl<B, C, P> ObjectProvider for ProjectionView<'_, B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    type Object = C::Object;
+    fn with_object<R>(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+        operation: impl FnOnce(&PublishedObject<Self::Object>) -> R,
+    ) -> ProviderResult<R> {
+        match self.resolve(context, path) {
+            ProviderResult::Found(resolved) => {
+                let (_ancestors, entry) = resolved.into_parts();
+                match self.publication(entry, context) {
+                    Ok(publication) => ProviderResult::Found(operation(&publication)),
+                    Err(error) => ProviderResult::Failure(error),
+                }
+            }
+            ProviderResult::NotFound => ProviderResult::NotFound,
+            ProviderResult::Failure(error) => ProviderResult::Failure(error),
+        }
+    }
+    fn execute_operation(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+        operation: impl FnOnce(&PublishedObject<Self::Object>) -> OperationAttempt,
+    ) -> ProviderResult<OperationAttempt> {
+        let entry = match self.resolve(context, path) {
+            ProviderResult::Found(entry) => entry,
+            ProviderResult::NotFound => return ProviderResult::NotFound,
+            ProviderResult::Failure(error) => return ProviderResult::Failure(error),
+        };
+        self.projection.backend.execute(context, entry, |resolved| {
+            // Backend validates retained lineage membership/identity and refreshes
+            // all metadata before this callback under the same boundary as dispatch.
+            if !lineage_matches_path(&resolved, path) {
+                return OperationAttempt::reject(wip_host::CallErrorKind::Internal);
+            }
+            if !self.lineage_visible(&resolved) {
+                return OperationAttempt::reject(wip_host::CallErrorKind::NotFound);
+            }
+            let (_ancestors, entry) = resolved.into_parts();
+            if let Err(error) = preflight(context) {
+                return OperationAttempt::reject(match error.kind() {
+                    wip_host::HostErrorKind::Internal => wip_host::CallErrorKind::Internal,
+                    wip_host::HostErrorKind::ResourceLimitExceeded => {
+                        wip_host::CallErrorKind::ResourceLimitExceeded
+                    }
+                });
+            }
+            match self.publication(entry, context) {
+                Ok(publication) => operation(&publication),
+                Err(error) => OperationAttempt::reject(match error.kind() {
+                    wip_host::HostErrorKind::Internal => wip_host::CallErrorKind::Internal,
+                    wip_host::HostErrorKind::ResourceLimitExceeded => {
+                        wip_host::CallErrorKind::ResourceLimitExceeded
+                    }
+                }),
+            }
+        })
+    }
+    fn authorize(
+        &self,
+        _: &str,
+        object: &Self::Object,
+        interface: &InterfaceRef,
+        operation: &str,
+    ) -> bool {
+        self.projection
+            .policy
+            .authorize(self.principal, object, interface, operation)
+    }
+}
+
+impl<B, C, P> ObjectProvider for Projection<B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object, Principal = ()>,
+{
+    type Object = C::Object;
+    fn with_object<R>(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+        operation: impl FnOnce(&PublishedObject<Self::Object>) -> R,
+    ) -> ProviderResult<R> {
+        self.view(&()).with_object(context, path, operation)
+    }
+    fn execute_operation(
+        &self,
+        context: &ExecutionContext,
+        path: &str,
+        operation: impl FnOnce(&PublishedObject<Self::Object>) -> OperationAttempt,
+    ) -> ProviderResult<OperationAttempt> {
+        self.view(&()).execute_operation(context, path, operation)
+    }
+    fn authorize(
+        &self,
+        path: &str,
+        object: &Self::Object,
+        interface: &InterfaceRef,
+        operation: &str,
+    ) -> bool {
+        self.view(&()).authorize(path, object, interface, operation)
+    }
+}
+
+impl<B, C, P> Projection<B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object, Principal = ()>,
+{
+    /// Observe the default unit-principal view.
+    pub fn observe(
+        &self,
+        context: &ExecutionContext,
+        request: &ObserveRequest,
+    ) -> Result<ObserveResponse, ProtocolError> {
+        self.view(&()).observe(context, request)
+    }
+    /// Fetch in the default unit-principal view.
+    pub fn fetch_interface(
+        &self,
+        request: &FetchInterfaceRequest,
+    ) -> Result<FetchInterfaceResponse, ProtocolError> {
+        self.view(&()).fetch_interface(request)
+    }
+}
+
+fn lineage_matches_path<E: BackendEntry>(resolved: &ResolvedEntry<E>, path: &str) -> bool {
+    let names: Vec<_> = if path == "/" {
+        vec![""]
+    } else {
+        std::iter::once("").chain(path[1..].split('/')).collect()
+    };
+    if resolved.ancestors().len() + 1 != names.len()
+        || resolved.target().name() != names[names.len() - 1]
+    {
+        return false;
+    }
+    resolved
+        .ancestors()
+        .iter()
+        .zip(names)
+        .all(|(entry, name)| entry.kind() == EntryKind::Directory && entry.name() == name)
+}
+
+fn read_boundary<T>(
+    operation: impl FnOnce() -> Result<T, ProtocolError>,
+) -> Result<T, ProtocolError> {
+    std::panic::catch_unwind(std::panic::AssertUnwindSafe(operation))
+        .unwrap_or_else(|_| Err(protocol(ProtocolErrorCode::Internal, "projection failed")))
+}
+
+fn internal() -> HostError {
+    HostError::internal(
+        "projection publication failed",
+        EffectGuarantee::NotCommitted,
+    )
+}
+fn protocol(code: ProtocolErrorCode, message: &str) -> ProtocolError {
+    ProtocolError {
+        code,
+        message: message.into(),
+    }
+}
+fn resource_protocol() -> ProtocolError {
+    protocol(
+        ProtocolErrorCode::ResourceLimitExceeded,
+        "projection resource limit exceeded",
+    )
+}
+fn read_error(error: HostError) -> ProtocolError {
+    match error.kind() {
+        wip_host::HostErrorKind::ResourceLimitExceeded => resource_protocol(),
+        wip_host::HostErrorKind::Internal => {
+            protocol(ProtocolErrorCode::Internal, "projection failed")
+        }
+    }
+}
+fn preflight(context: &ExecutionContext) -> Result<(), HostError> {
+    if context.cancellation().is_cancelled()
+        || context
+            .deadline()
+            .is_some_and(|deadline| std::time::Instant::now() >= deadline)
+        || context.resource_budget() == Some(0)
+    {
+        Err(HostError::resource_limit(
+            "projection work limit exceeded",
+            EffectGuarantee::NotCommitted,
+        ))
+    } else {
+        Ok(())
+    }
+}

crates/wip-fs-server/src/http_adapter.rs

@@ -0,0 +1,435 @@
+//! Framework-neutral standard WIP over HTTP mapping for a projection view.
+
+use std::time::Instant;
+
+use http::header::ALLOW;
+use http::{Request, Response, StatusCode};
+use wip_host::{ExecutionContext, ObjectProvider};
+use wip_http::{
+    CodecError, EncodeHttpError, Endpoint, RequestMetadataError, Route,
+    decode_call_operation_metadata, decode_fetch_interface_request, decode_observe_request,
+    encode_call_operation_response, encode_fetch_interface_response, encode_observe_response,
+    encode_protocol_error_response, validate_http_request,
+};
+use wip_protocol::{ProtocolError, ProtocolErrorCode, ProtocolInteraction};
+
+use crate::engine::ProjectionView;
+use crate::{Composition, FilesystemBackend, ProjectionPolicy, ResourceLimits};
+
+/// Standard HTTP routes and codecs over a caller-scoped projection view.
+///
+/// The adapter borrows the view and endpoint without owning a listener, selecting
+/// a principal, or imposing a new execution context. Integrations must enforce
+/// the request body limit while collecting bytes, before calling this adapter.
+pub struct HttpAdapter<'a, 'view, B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    view: &'a ProjectionView<'view, B, C, P>,
+    endpoint: &'a Endpoint,
+    limits: ResourceLimits,
+}
+
+impl<'a, 'view, B, C, P> HttpAdapter<'a, 'view, B, C, P>
+where
+    B: FilesystemBackend,
+    C: Composition<B::Entry>,
+    P: ProjectionPolicy<B::Entry, C::Object>,
+{
+    /// Creates an adapter for an already-selected principal's projection view.
+    #[must_use]
+    pub fn new(
+        view: &'a ProjectionView<'view, B, C, P>,
+        endpoint: &'a Endpoint,
+        limits: ResourceLimits,
+    ) -> Self {
+        Self {
+            view,
+            endpoint,
+            limits,
+        }
+    }
+
+    /// Handles one buffered request using the supplied execution controls.
+    ///
+    /// Observation and operation dispatch receive the original context, including
+    /// cancellation and resource budget. An elapsed deadline after dispatch keeps
+    /// the listener's existing empty HTTP 504 transport-failure behavior.
+    #[must_use]
+    pub fn handle_http_with_context(
+        &self,
+        request: Request<Vec<u8>>,
+        context: &ExecutionContext,
+    ) -> Response<Vec<u8>> {
+        let Some(route) = self.route(request.uri()) else {
+            return empty_response(StatusCode::NOT_FOUND);
+        };
+        if let Err(error) = validate_http_request(self.endpoint, route, &request) {
+            return self.metadata_error(error);
+        }
+        let response = match route {
+            Route::Observe => self.observe(request.body(), context),
+            Route::FetchInterface => self.fetch_interface(request.body()),
+            Route::CallOperation => self.call_operation(request.body(), context),
+        };
+        if context
+            .deadline()
+            .is_some_and(|deadline| Instant::now() >= deadline)
+        {
+            empty_response(StatusCode::GATEWAY_TIMEOUT)
+        } else {
+            response
+        }
+    }
+
+    fn route(&self, uri: &http::Uri) -> Option<Route> {
+        if uri.query().is_some() {
+            return None;
+        }
+        [Route::Observe, Route::FetchInterface, Route::CallOperation]
+            .into_iter()
+            .find(|route| self.endpoint.route(*route).path() == uri.path())
+    }
+
+    fn observe(&self, body: &[u8], context: &ExecutionContext) -> Response<Vec<u8>> {
+        let request = match decode_observe_request(body, self.limits.wire) {
+            Ok(request) => request,
+            Err(error) => return self.codec_error(ProtocolInteraction::Observe, error),
+        };
+        match self.view.observe(context, &request) {
+            Ok(tree) => {
+                encode_observe_response(&request, &tree, self.limits.wire).unwrap_or_else(|error| {
+                    self.read_encode_error(ProtocolInteraction::Observe, error)
+                })
+            }
+            Err(error) => self.protocol_error(ProtocolInteraction::Observe, &error),
+        }
+    }
+
+    fn fetch_interface(&self, body: &[u8]) -> Response<Vec<u8>> {
+        let request = match decode_fetch_interface_request(body, self.limits.wire) {
+            Ok(request) => request,
+            Err(error) => return self.codec_error(ProtocolInteraction::FetchInterface, error),
+        };
+        match self.view.fetch_interface(&request) {
+            Ok(interface) => {
+                encode_fetch_interface_response(&request, &interface, self.limits.wire)
+                    .unwrap_or_else(|error| {
+                        self.read_encode_error(ProtocolInteraction::FetchInterface, error)
+                    })
+            }
+            Err(error) => self.protocol_error(ProtocolInteraction::FetchInterface, &error),
+        }
+    }
+
+    fn call_operation(&self, body: &[u8], context: &ExecutionContext) -> Response<Vec<u8>> {
+        let metadata = match decode_call_operation_metadata(body, self.limits.wire) {
+            Ok(metadata) => metadata,
+            Err(error) => return self.codec_error(ProtocolInteraction::CallOperation, error),
+        };
+        let decoded = std::sync::Mutex::new(None);
+        let execution = self.view.call_operation_with_context_and_decoder(
+            context,
+            metadata.target.clone(),
+            metadata.interface.clone(),
+            metadata.operation.clone(),
+            |descriptor| {
+                let request = metadata.decode_request(body, descriptor, self.limits.wire)?;
+                let arguments = request.arguments.clone();
+                *decoded.lock().unwrap_or_else(|error| error.into_inner()) =
+                    Some((request, descriptor.clone()));
+                Ok::<_, CodecError>(arguments)
+            },
+        );
+        match execution.map_err(|error| error.protocol_error()) {
+            Ok(result) => {
+                let Some((request, descriptor)) = decoded
+                    .into_inner()
+                    .unwrap_or_else(|error| error.into_inner())
+                else {
+                    return self.protocol_error(
+                        ProtocolInteraction::CallOperation,
+                        &operation_outcome_unknown(),
+                    );
+                };
+                encode_call_operation_response(&request, &descriptor, &result, self.limits.wire)
+                    .unwrap_or_else(|error| self.operation_encode_error(error))
+            }
+            Err(error) => self.protocol_error(ProtocolInteraction::CallOperation, &error),
+        }
+    }
+
+    fn operation_encode_error(&self, error: EncodeHttpError) -> Response<Vec<u8>> {
+        if matches!(&error, EncodeHttpError::Codec(codec) if is_transport_limit(codec)) {
+            return empty_response(StatusCode::INTERNAL_SERVER_ERROR);
+        }
+        // Any successfully executed operation may have committed effects. Its
+        // name cannot establish a non-commit guarantee after response failure.
+        self.protocol_error(
+            ProtocolInteraction::CallOperation,
+            &operation_outcome_unknown(),
+        )
+    }
+
+    fn metadata_error(&self, error: RequestMetadataError) -> Response<Vec<u8>> {
+        match error {
+            RequestMetadataError::NotFound => empty_response(StatusCode::NOT_FOUND),
+            error @ RequestMetadataError::MethodNotAllowed => Response::builder()
+                .status(error.status())
+                .header(
+                    ALLOW,
+                    error
+                        .allow()
+                        .expect("method-not-allowed metadata has an Allow value"),
+                )
+                .body(Vec::new())
+                .expect("static method response is valid"),
+            RequestMetadataError::UnsupportedMediaType => {
+                empty_response(StatusCode::UNSUPPORTED_MEDIA_TYPE)
+            }
+            RequestMetadataError::NotAcceptable => empty_response(StatusCode::NOT_ACCEPTABLE),
+        }
+    }
+
+    fn codec_error(
+        &self,
+        interaction: ProtocolInteraction,
+        error: CodecError,
+    ) -> Response<Vec<u8>> {
+        if is_transport_limit(&error) {
+            empty_response(StatusCode::PAYLOAD_TOO_LARGE)
+        } else {
+            self.protocol_error(
+                interaction,
+                &ProtocolError {
+                    code: ProtocolErrorCode::InvalidRequest,
+                    message: "malformed WIP request".into(),
+                },
+            )
+        }
+    }
+
+    fn read_encode_error(
+        &self,
+        interaction: ProtocolInteraction,
+        error: EncodeHttpError,
+    ) -> Response<Vec<u8>> {
+        match error {
+            EncodeHttpError::Codec(codec) if is_transport_limit(&codec) => {
+                empty_response(StatusCode::INTERNAL_SERVER_ERROR)
+            }
+            _ => self.protocol_error(
+                interaction,
+                &ProtocolError {
+                    code: ProtocolErrorCode::Internal,
+                    message: "HTTP adapter failed".into(),
+                },
+            ),
+        }
+    }
+
+    fn protocol_error(
+        &self,
+        interaction: ProtocolInteraction,
+        error: &ProtocolError,
+    ) -> Response<Vec<u8>> {
+        // Engine and policy diagnostics may contain paths, argument values, or
+        // backend details. Emit only fixed, bounded diagnostics on the wire.
+        let sanitized = ProtocolError {
+            code: error.code,
+            message: sanitized_message(error.code).into(),
+        };
+        encode_protocol_error_response(interaction, &sanitized, self.limits.wire)
+            .unwrap_or_else(|_| empty_response(StatusCode::INTERNAL_SERVER_ERROR))
+    }
+}
+
+fn operation_outcome_unknown() -> ProtocolError {
+    ProtocolError {
+        code: ProtocolErrorCode::OperationOutcomeUnknown,
+        message: "operation completed but its response could not be encoded".into(),
+    }
+}
+
+fn sanitized_message(code: ProtocolErrorCode) -> &'static str {
+    match code {
+        ProtocolErrorCode::InvalidRequest => "malformed WIP request",
+        ProtocolErrorCode::NotFound => "target path is not published",
+        ProtocolErrorCode::InterfaceNotFound => "interface is not published",
+        ProtocolErrorCode::InterfaceMismatch => "interface is not published on the target",
+        ProtocolErrorCode::OperationNotFound => "operation is not published",
+        ProtocolErrorCode::InvalidArguments => "arguments do not match the operation",
+        ProtocolErrorCode::ValidatorRequired => "object validator is required",
+        ProtocolErrorCode::ValidatorMismatch => "object validator does not match",
+        ProtocolErrorCode::InterfaceValidatorRequired => "interface validator is required",
+        ProtocolErrorCode::InterfaceValidatorMismatch => "interface validator does not match",
+        ProtocolErrorCode::PermissionDenied => "operation is not permitted",
+        ProtocolErrorCode::ResourceLimitExceeded => "projection resource limit exceeded",
+        ProtocolErrorCode::Internal => "HTTP adapter failed",
+        ProtocolErrorCode::OperationOutcomeUnknown => "operation outcome is unknown",
+    }
+}
+
+fn is_transport_limit(error: &CodecError) -> bool {
+    matches!(
+        error,
+        CodecError::BodyTooLarge { .. } | CodecError::NestingTooDeep { .. }
+    )
+}
+
+fn empty_response(status: StatusCode) -> Response<Vec<u8>> {
+    Response::builder()
+        .status(status)
+        .body(Vec::new())
+        .expect("static status builds an HTTP response")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::tempdir;
+    use wip_http::{
+        DecodedResponse, Limits, decode_fetch_interface_response, decode_observe_response,
+        encode_fetch_interface_request, encode_observe_request,
+    };
+    use wip_protocol::{FetchInterfaceRequest, ObserveRequest};
+
+    #[test]
+    fn adapter_serves_observation_and_interface_fetch_without_server() {
+        let root = tempdir().unwrap();
+        std::fs::write(root.path().join("file"), b"contents").unwrap();
+        let limits = ResourceLimits::default();
+        let projection =
+            crate::default_projection(root.path(), crate::AccessMode::ReadOnly, limits).unwrap();
+        let view = projection.view(&());
+        let endpoint = Endpoint::parse("http://localhost/custom").unwrap();
+        let adapter = HttpAdapter::new(&view, &endpoint, limits);
+        let context = ExecutionContext::new();
+        let request = ObserveRequest {
+            path: "/file".into(),
+            depth: 0,
+        };
+        let response = adapter.handle_http_with_context(
+            encode_observe_request(&endpoint, &request, limits.wire).unwrap(),
+            &context,
+        );
+        let DecodedResponse::Success(observation) =
+            decode_observe_response(&request, &response, limits.wire).unwrap()
+        else {
+            panic!("expected observation success")
+        };
+        let request = FetchInterfaceRequest {
+            interface: observation.object.interfaces[0].clone(),
+        };
+        let response = adapter.handle_http_with_context(
+            encode_fetch_interface_request(&endpoint, &request, limits.wire).unwrap(),
+            &context,
+        );
+        assert!(matches!(
+            decode_fetch_interface_response(&request, &response, limits.wire).unwrap(),
+            DecodedResponse::Success(_)
+        ));
+    }
+
+    #[test]
+    fn adapter_preserves_transport_boundaries_and_execution_context() {
+        let root = tempdir().unwrap();
+        let limits = ResourceLimits::default();
+        let projection =
+            crate::default_projection(root.path(), crate::AccessMode::ReadOnly, limits).unwrap();
+        let view = projection.view(&());
+        let endpoint = Endpoint::parse("http://localhost/wip").unwrap();
+        let adapter = HttpAdapter::new(&view, &endpoint, limits);
+        let context = ExecutionContext::new();
+        for uri in [
+            "/wip/v1/observe?query=1",
+            "/wip/v1/unknown",
+            "/wip/v1/observe/extra",
+        ] {
+            let response = adapter.handle_http_with_context(
+                Request::builder().uri(uri).body(Vec::new()).unwrap(),
+                &context,
+            );
+            assert_eq!(response.status(), StatusCode::NOT_FOUND);
+            assert!(response.body().is_empty());
+        }
+        let response = adapter.handle_http_with_context(
+            Request::builder()
+                .uri("/wip/v1/observe")
+                .body(Vec::new())
+                .unwrap(),
+            &context,
+        );
+        assert_eq!(response.status(), StatusCode::METHOD_NOT_ALLOWED);
+        assert_eq!(response.headers()[ALLOW], "POST");
+        assert!(response.body().is_empty());
+        let request = ObserveRequest {
+            path: "/".into(),
+            depth: 0,
+        };
+        let response = adapter.handle_http_with_context(
+            encode_observe_request(&endpoint, &request, limits.wire).unwrap(),
+            &ExecutionContext::new().with_resource_budget(0),
+        );
+        let text = std::str::from_utf8(response.body()).unwrap();
+        assert!(text.contains("resource_limit_exceeded"));
+        let response = adapter.handle_http_with_context(
+            encode_observe_request(&endpoint, &request, limits.wire).unwrap(),
+            &ExecutionContext::new().with_deadline(Instant::now()),
+        );
+        assert_eq!(response.status(), StatusCode::GATEWAY_TIMEOUT);
+        assert!(response.body().is_empty());
+    }
+
+    #[test]
+    fn post_success_encoding_is_unknown_except_empty_transport_limit_failure() {
+        let root = tempdir().unwrap();
+        let limits = ResourceLimits::default();
+        let projection =
+            crate::default_projection(root.path(), crate::AccessMode::ReadOnly, limits).unwrap();
+        let view = projection.view(&());
+        let endpoint = Endpoint::parse("http://localhost/wip").unwrap();
+        let adapter = HttpAdapter::new(&view, &endpoint, limits);
+        let error = decode_observe_request(b"{", limits.wire).unwrap_err();
+        let response = adapter.operation_encode_error(EncodeHttpError::Codec(error));
+        assert!(
+            std::str::from_utf8(response.body())
+                .unwrap()
+                .contains("operation_outcome_unknown")
+        );
+        let tiny_limits = Limits::new(1, 1, 1).unwrap();
+        let error = decode_observe_request(b"{}", tiny_limits).unwrap_err();
+        assert!(is_transport_limit(&error));
+        let response = adapter.operation_encode_error(EncodeHttpError::Codec(error));
+        assert_eq!(response.status(), StatusCode::INTERNAL_SERVER_ERROR);
+        assert!(response.body().is_empty());
+        assert!(!response.headers().contains_key(http::header::CONTENT_TYPE));
+    }
+
+    #[test]
+    fn engine_error_diagnostics_are_sanitized_and_bounded() {
+        let root = tempdir().unwrap();
+        let limits = ResourceLimits::default();
+        let projection =
+            crate::default_projection(root.path(), crate::AccessMode::ReadOnly, limits).unwrap();
+        let view = projection.view(&());
+        let endpoint = Endpoint::parse("http://localhost/wip").unwrap();
+        let adapter = HttpAdapter::new(&view, &endpoint, limits);
+        let response = adapter.protocol_error(
+            ProtocolInteraction::Observe,
+            &ProtocolError {
+                code: ProtocolErrorCode::Internal,
+                message: "/private/backend/secret".repeat(1000),
+            },
+        );
+        assert!(response.body().len() < 512);
+        assert!(
+            !std::str::from_utf8(response.body())
+                .unwrap()
+                .contains("secret")
+        );
+        assert_eq!(response.status(), StatusCode::INTERNAL_SERVER_ERROR);
+    }
+}

crates/wip-fs-server/src/lib.rs

@@ -4,15 +4,49 @@
 //!
 //! - [`wip_protocol`] owns logical requests and responses;
 //! - [`wip_host`] owns object publication, validators, and typed dispatch;
-//! - [`wip_http`] owns routes, JSON, envelopes, batching, and status mapping;
+//! - [`wip_http`] owns routes, JSON, envelopes, and status mapping;
 //! - this crate owns the filesystem capability boundary and the real HTTP listener.
 //!
+//! # Extension boundary
+//!
+//! [`Projection`] composes a [`FilesystemBackend`], typed [`Composition`] and
+//! [`ProjectionPolicy`]. External local Objects can wrap a [`BackendEntry`] and
+//! implement generated interfaces without orphan-rule workarounds. The backend
+//! retains a root-confined target and atomic validator/dispatch boundary; the
+//! engine owns recursive observation and standard host typed validation. No
+//! listener is needed to use [`ProjectionView`]. [`HttpAdapter`] applies the
+//! existing standard HTTP binding to a deployment-established principal view.
+//!
+//! Backends and Operations are trusted code, responsible for truthful effects,
+//! public-only metadata and ongoing execution-context bounds. Policies must be
+//! stable within a view; changing descriptor visibility requires new reference
+//! lifetimes. See the crate README for implementer security and migration details.
+//!
+//! ```no_run
+//! use wip_fs_server::{default_projection, AccessMode, ResourceLimits};
+//! use wip_host::{ExecutionContext, ObjectProvider};
+//! use wip_protocol::ObserveRequest;
+//!
+//! let engine = default_projection(std::path::Path::new("./public"),
+//!     AccessMode::ReadOnly, ResourceLimits::default())?;
+//! let view = engine.view(&());
+//! let context = ExecutionContext::new().with_resource_budget(128);
+//! let tree = view.observe(&context, &ObserveRequest { path: "/".into(), depth: 1 })?;
+//! assert_eq!(tree.object.name, "");
+//! let object = view.observe_object_with_context(&context, "/")?;
+//! assert!(object.interfaces.is_empty());
+//! # Ok::<(), Box<dyn std::error::Error>>(())
+//! ```
+//!
 //! The built-in HTTP listener is intentionally loopback-only. TLS termination,
 //! certificates, authentication, and externally visible schemes are independent
 //! deployment concerns rather than WIP transport profiles.
 
 #![deny(missing_docs)]
 
+mod defaults;
+mod engine;
+mod http_adapter;
 mod interfaces;
 mod projection;
 mod server;
@@ -21,7 +55,17 @@ use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::path::PathBuf;
 use std::time::Duration;
 
-pub use interfaces::{FileRead, FileWrite, SymlinkInspect};
+pub use defaults::{DefaultComposition, DefaultInterfaces, DefaultObject, default_projection};
+pub use engine::{
+    BackendEntry, Composition, DefaultPolicy, EntryKind, FilesystemBackend, Projection,
+    ProjectionPolicy, ProjectionView, ResolvedEntry,
+};
+pub use http_adapter::HttpAdapter;
+pub use interfaces::{
+    FileRead, FileReadDefinition, FileWrite, FileWriteDefinition, SymlinkInspect,
+    SymlinkInspectDefinition,
+};
+pub use projection::{LinuxBackend, LinuxEntry};
 pub use server::{BoundServer, ServerBuildError, WipFsServer};
 
 /// Filesystem capabilities published by regular files.
@@ -36,7 +80,7 @@ pub enum AccessMode {
 /// Bounded resource policy applied by the HTTP adapter and filesystem provider.
 #[derive(Debug, Clone, Copy)]
 pub struct ResourceLimits {
-    /// Standard JSON, body-size, nesting, and batch limits.
+    /// Standard JSON, body-size, and nesting limits.
     pub wire: wip_http::Limits,
     /// Maximum bytes returned by one file read.
     pub max_file_read_bytes: usize,
@@ -59,7 +103,7 @@ pub struct ResourceLimits {
 impl Default for ResourceLimits {
     fn default() -> Self {
         Self {
-            wire: wip_http::Limits::new(256 * 1024, 2 * 1024 * 1024, 64, 64)
+            wire: wip_http::Limits::new(256 * 1024, 2 * 1024 * 1024, 64)
                 .expect("default wire limits are nonzero"),
             max_file_read_bytes: 1024 * 1024,
             max_file_write_bytes: 1024 * 1024,

crates/wip-fs-server/src/server.rs

@@ -6,26 +6,19 @@ use std::thread;
 use std::time::{Duration, Instant};
 
 use http::{Request, Response, StatusCode};
-use wip_host::{ExecutionContext, ObjectProvider};
+use wip_host::ExecutionContext;
-use wip_http::{
+use wip_http::Endpoint;
-    BatchRequestKind, BatchResponse, BatchResponseItem, BatchSuccess, CodecError, EncodeHttpError,
-    Endpoint, RequestMetadataError, ResourceLimitKind, Route, decode_batch_request,
-    decode_call_operation_metadata, decode_fetch_interface_request, decode_observe_request,
-    encode_batch_error_response, encode_batch_resource_limit_error_response, encode_batch_response,
-    encode_call_operation_response, encode_fetch_interface_response, encode_observe_response,
-    encode_protocol_error_response, encode_resource_limit_error_response, validate_http_request,
-};
-use wip_protocol::{ProtocolError, ProtocolErrorCode, ProtocolInteraction};
 
-use crate::projection::Projection;
+use crate::engine::Projection;
-use crate::{ConfigError, ServerConfig};
+use crate::http_adapter::HttpAdapter;
+use crate::{ConfigError, DefaultComposition, DefaultPolicy, LinuxBackend, ServerConfig};
 
-/// Filesystem projection and framework-neutral standard WIP request adapter.
+/// Default Linux filesystem projection and bounded loopback HTTP listener.
 pub struct WipFsServer {
     config: ServerConfig,
     endpoint: Endpoint,
     effective_root: std::path::PathBuf,
-    projection: Arc<Projection>,
+    projection: Arc<Projection<LinuxBackend, DefaultComposition, DefaultPolicy>>,
 }
 
 impl WipFsServer {
@@ -33,8 +26,8 @@ impl WipFsServer {
     pub fn new(config: ServerConfig) -> Result<Self, ServerBuildError> {
         config.validate()?;
         let endpoint = config.endpoint()?;
-        let projection = Projection::open(&config.root, config.access, config.limits)?;
+        let projection = crate::default_projection(&config.root, config.access, config.limits)?;
-        let effective_root = projection.effective_root()?;
+        let effective_root = projection.backend().effective_root()?;
         Ok(Self {
             config,
             endpoint,
@@ -68,21 +61,12 @@ impl WipFsServer {
         request: Request<Vec<u8>>,
         deadline: Instant,
     ) -> Response<Vec<u8>> {
-        let Some(route) = self.route(request.uri().path()) else {
-            return empty_response(StatusCode::NOT_FOUND);
-        };
-        if let Err(error) = validate_http_request(&self.endpoint, route, &request) {
-            return self.metadata_error(route, error);
-        }
         let context = ExecutionContext::new()
             .with_deadline(deadline)
             .with_resource_budget(u64::from(self.config.limits.max_observation_nodes));
-        match route {
+        let view = self.projection.view(&());
-            Route::Observe => self.observe(request.body(), &context),
+        HttpAdapter::new(&view, &self.endpoint, self.config.limits)
-            Route::FetchInterface => self.fetch_interface(request.body()),
+            .handle_http_with_context(request, &context)
-            Route::CallOperation => self.call_operation(request.body(), &context),
-            Route::Batch => self.batch(request.body(), &context),
-        }
     }
 
     /// Binds the built-in bounded loopback HTTP listener.
@@ -105,237 +89,6 @@ impl WipFsServer {
             listener: Arc::new(listener),
         })
     }
-
-    fn route(&self, path: &str) -> Option<Route> {
-        [
-            Route::Observe,
-            Route::FetchInterface,
-            Route::CallOperation,
-            Route::Batch,
-        ]
-        .into_iter()
-        .find(|route| self.endpoint.route(*route).path() == path)
-    }
-
-    fn observe(&self, body: &[u8], context: &ExecutionContext) -> Response<Vec<u8>> {
-        let request = match decode_observe_request(body, self.config.limits.wire) {
-            Ok(request) => request,
-            Err(error) => return self.codec_error(ProtocolInteraction::Observe, error),
-        };
-        match self.projection.observe(context, &request) {
-            Ok(tree) => encode_observe_response(&request, &tree, self.config.limits.wire)
-                .unwrap_or_else(|error| {
-                    self.read_encode_error(ProtocolInteraction::Observe, error)
-                }),
-            Err(error) => self.protocol_error(ProtocolInteraction::Observe, &error, None),
-        }
-    }
-
-    fn fetch_interface(&self, body: &[u8]) -> Response<Vec<u8>> {
-        let request = match decode_fetch_interface_request(body, self.config.limits.wire) {
-            Ok(request) => request,
-            Err(error) => return self.codec_error(ProtocolInteraction::FetchInterface, error),
-        };
-        match self.projection.fetch_interface(&request) {
-            Ok(interface) => {
-                encode_fetch_interface_response(&request, &interface, self.config.limits.wire)
-                    .unwrap_or_else(|error| {
-                        self.read_encode_error(ProtocolInteraction::FetchInterface, error)
-                    })
-            }
-            Err(error) => self.protocol_error(ProtocolInteraction::FetchInterface, &error, None),
-        }
-    }
-
-    fn call_operation(&self, body: &[u8], context: &ExecutionContext) -> Response<Vec<u8>> {
-        let metadata = match decode_call_operation_metadata(body, self.config.limits.wire) {
-            Ok(metadata) => metadata,
-            Err(error) => return self.codec_error(ProtocolInteraction::CallOperation, error),
-        };
-        let may_commit = metadata.operation == "replace";
-        let decoded = std::sync::Mutex::new(None);
-        let execution = self.projection.call_operation_with_context_and_decoder(
-            context,
-            metadata.target.clone(),
-            metadata.interface.clone(),
-            metadata.operation.clone(),
-            |descriptor| {
-                let request = metadata.decode_request(body, descriptor, self.config.limits.wire)?;
-                let arguments = request.arguments.clone();
-                *decoded.lock().unwrap_or_else(|error| error.into_inner()) =
-                    Some((request, descriptor.clone()));
-                Ok::<_, CodecError>(arguments)
-            },
-        );
-        match execution.map_err(|error| error.protocol_error()) {
-            Ok(result) => {
-                let Some((request, descriptor)) = decoded
-                    .into_inner()
-                    .unwrap_or_else(|error| error.into_inner())
-                else {
-                    let error = ProtocolError {
-                        code: if may_commit {
-                            ProtocolErrorCode::OperationOutcomeUnknown
-                        } else {
-                            ProtocolErrorCode::Internal
-                        },
-                        message: "operation completed without response metadata".into(),
-                    };
-                    return self.protocol_error(ProtocolInteraction::CallOperation, &error, None);
-                };
-                encode_call_operation_response(
-                    &request,
-                    &descriptor,
-                    &result,
-                    self.config.limits.wire,
-                )
-                .unwrap_or_else(|encode_error| {
-                    if !may_commit {
-                        return self
-                            .read_encode_error(ProtocolInteraction::CallOperation, encode_error);
-                    }
-                    // Replacement may already be committed, so a response
-                    // encoding failure cannot carry a non-commit guarantee.
-                    let error = ProtocolError {
-                        code: ProtocolErrorCode::OperationOutcomeUnknown,
-                        message: "operation completed but its response could not be encoded".into(),
-                    };
-                    self.protocol_error(ProtocolInteraction::CallOperation, &error, None)
-                })
-            }
-            Err(error) => self.protocol_error(ProtocolInteraction::CallOperation, &error, None),
-        }
-    }
-
-    fn batch(&self, body: &[u8], context: &ExecutionContext) -> Response<Vec<u8>> {
-        let request = match decode_batch_request(body, self.config.limits.wire) {
-            Ok(request) => request,
-            Err(error) => return self.batch_codec_error(error),
-        };
-        let responses = request
-            .requests
-            .iter()
-            .map(|item| {
-                let outcome = match &item.request {
-                    BatchRequestKind::Observe(request) => self
-                        .projection
-                        .observe(context, request)
-                        .map(BatchSuccess::Observe),
-                    BatchRequestKind::FetchInterface(request) => self
-                        .projection
-                        .fetch_interface(request)
-                        .map(BatchSuccess::FetchInterface),
-                    BatchRequestKind::Invalid { error, .. } => Err(error.clone()),
-                };
-                BatchResponseItem {
-                    id: item.id.clone(),
-                    outcome,
-                }
-            })
-            .collect();
-        let response = BatchResponse { responses };
-        encode_batch_response(&request, &response, self.config.limits.wire).unwrap_or_else(
-            |error| match error {
-                EncodeHttpError::Codec(codec) => self.batch_codec_error(codec),
-                EncodeHttpError::Http(_) => self.batch_top_error(&internal_error(), None),
-            },
-        )
-    }
-
-    fn metadata_error(&self, route: Route, error: RequestMetadataError) -> Response<Vec<u8>> {
-        match error {
-            RequestMetadataError::InvalidRequest(_) => self.protocol_error(
-                interaction(route),
-                &ProtocolError {
-                    code: ProtocolErrorCode::InvalidRequest,
-                    message: "invalid HTTP request metadata".into(),
-                },
-                None,
-            ),
-            RequestMetadataError::UnsupportedMediaType => {
-                empty_response(StatusCode::UNSUPPORTED_MEDIA_TYPE)
-            }
-            RequestMetadataError::NotAcceptable => empty_response(StatusCode::NOT_ACCEPTABLE),
-        }
-    }
-
-    fn codec_error(
-        &self,
-        interaction: ProtocolInteraction,
-        error: CodecError,
-    ) -> Response<Vec<u8>> {
-        if let Some(kind) = error.resource_limit_kind() {
-            self.protocol_error(interaction, &resource_error(), Some(kind))
-        } else {
-            self.protocol_error(
-                interaction,
-                &ProtocolError {
-                    code: ProtocolErrorCode::InvalidRequest,
-                    message: "malformed WIP request".into(),
-                },
-                None,
-            )
-        }
-    }
-
-    fn batch_codec_error(&self, error: CodecError) -> Response<Vec<u8>> {
-        if let Some(kind) = error.resource_limit_kind() {
-            self.batch_top_error(&resource_error(), Some(kind))
-        } else {
-            self.batch_top_error(
-                &ProtocolError {
-                    code: ProtocolErrorCode::InvalidRequest,
-                    message: "malformed WIP batch request".into(),
-                },
-                None,
-            )
-        }
-    }
-
-    fn read_encode_error(
-        &self,
-        interaction: ProtocolInteraction,
-        error: EncodeHttpError,
-    ) -> Response<Vec<u8>> {
-        match error {
-            EncodeHttpError::Codec(codec) if codec.resource_limit_kind().is_some() => {
-                self.protocol_error(interaction, &resource_error(), codec.resource_limit_kind())
-            }
-            _ => self.protocol_error(interaction, &internal_error(), None),
-        }
-    }
-
-    fn protocol_error(
-        &self,
-        interaction: ProtocolInteraction,
-        error: &ProtocolError,
-        resource_kind: Option<ResourceLimitKind>,
-    ) -> Response<Vec<u8>> {
-        let encoded = match resource_kind {
-            Some(kind) => encode_resource_limit_error_response(
-                interaction,
-                error,
-                kind,
-                self.config.limits.wire,
-            ),
-            None => encode_protocol_error_response(interaction, error, self.config.limits.wire),
-        };
-        encoded.unwrap_or_else(|_| empty_response(StatusCode::INTERNAL_SERVER_ERROR))
-    }
-
-    fn batch_top_error(
-        &self,
-        error: &ProtocolError,
-        resource_kind: Option<ResourceLimitKind>,
-    ) -> Response<Vec<u8>> {
-        let encoded = match resource_kind {
-            Some(kind) => {
-                encode_batch_resource_limit_error_response(error, kind, self.config.limits.wire)
-            }
-            None => encode_batch_error_response(error, self.config.limits.wire),
-        };
-        encoded.unwrap_or_else(|_| empty_response(StatusCode::INTERNAL_SERVER_ERROR))
-    }
 }
 
 /// Bound real HTTP listener for a [`WipFsServer`].
@@ -404,7 +157,7 @@ struct ParsedRequestHead {
 enum IntakeError {
     Timeout,
     HeaderTooLarge,
-    PayloadTooLarge { target: String },
+    PayloadTooLarge,
     BadRequest,
     Socket,
 }
@@ -425,9 +178,7 @@ fn serve_connection(service: &WipFsServer, mut stream: TcpStream) {
         Err(IntakeError::HeaderTooLarge) => {
             Some(empty_response(StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE))
         }
-        Err(IntakeError::PayloadTooLarge { target }) => {
+        Err(IntakeError::PayloadTooLarge) => Some(empty_response(StatusCode::PAYLOAD_TOO_LARGE)),
-            Some(payload_too_large_response(service, &target))
-        }
         Err(IntakeError::BadRequest) => Some(empty_response(StatusCode::BAD_REQUEST)),
         Err(IntakeError::Timeout | IntakeError::Socket) => None,
     };
@@ -466,9 +217,7 @@ fn read_http_request(
 
     let parsed = parse_request_head(&received[..header_end])?;
     if parsed.content_length > maximum_body {
-        return Err(IntakeError::PayloadTooLarge {
+        return Err(IntakeError::PayloadTooLarge);
-            target: parsed.target,
-        });
     }
     let mut body = Vec::with_capacity(parsed.content_length);
     let buffered = &received[header_end..];
@@ -567,27 +316,6 @@ fn read_with_deadline(
     })
 }
 
-fn payload_too_large_response(service: &WipFsServer, target: &str) -> Response<Vec<u8>> {
-    let route = service.route(target.split('?').next().unwrap_or_default());
-    route.map_or_else(
-        || empty_response(StatusCode::PAYLOAD_TOO_LARGE),
-        |route| {
-            if route == Route::Batch {
-                service.batch_top_error(
-                    &resource_error(),
-                    Some(ResourceLimitKind::RepresentationBytes),
-                )
-            } else {
-                service.protocol_error(
-                    interaction(route),
-                    &resource_error(),
-                    Some(ResourceLimitKind::RepresentationBytes),
-                )
-            }
-        },
-    )
-}
-
 fn write_http_response(
     stream: &mut TcpStream,
     response: &Response<Vec<u8>>,
@@ -648,29 +376,6 @@ fn write_all_with_deadline(
     stream.flush()
 }
 
-fn interaction(route: Route) -> ProtocolInteraction {
-    match route {
-        Route::Observe => ProtocolInteraction::Observe,
-        Route::FetchInterface => ProtocolInteraction::FetchInterface,
-        Route::CallOperation => ProtocolInteraction::CallOperation,
-        Route::Batch => ProtocolInteraction::Observe,
-    }
-}
-
-fn resource_error() -> ProtocolError {
-    ProtocolError {
-        code: ProtocolErrorCode::ResourceLimitExceeded,
-        message: "configured resource limit exceeded".into(),
-    }
-}
-
-fn internal_error() -> ProtocolError {
-    ProtocolError {
-        code: ProtocolErrorCode::Internal,
-        message: "filesystem server failed".into(),
-    }
-}
-
 fn empty_response(status: StatusCode) -> Response<Vec<u8>> {
     Response::builder()
         .status(status)

crates/wip-fs-server/tests/end_to_end.rs

@@ -9,10 +9,9 @@ use std::time::{Duration, Instant};
 use tempfile::tempdir;
 use wip_fs_server::{AccessMode, ServerConfig, WipFsServer};
 use wip_http::{
-    BatchRequest, BatchRequestItem, BatchRequestKind, BatchResponse, BatchSuccess, DecodedResponse,
+    ClientResponseError, DecodedResponse, Endpoint, JSON_CONTENT_TYPE, Limits, Route,
-    Endpoint, JSON_CONTENT_TYPE, Limits, Route, decode_batch_request, decode_batch_response,
+    TransportFailureKind, decode_call_operation_response, decode_fetch_interface_response,
-    decode_call_operation_response, decode_fetch_interface_response, decode_observe_response,
+    decode_observe_response, encode_call_operation_request, encode_fetch_interface_request,
-    encode_batch_request, encode_call_operation_request, encode_fetch_interface_request,
     encode_observe_request,
 };
 use wip_protocol::{
@@ -21,7 +20,7 @@ use wip_protocol::{
 };
 
 #[test]
-fn real_listener_serves_three_core_interactions_batch_and_write() {
+fn real_listener_serves_three_core_interactions_and_write() {
     let temporary = tempdir().expect("temporary root");
     std::fs::write(temporary.path().join("hello.txt"), b"hello world").expect("write file");
     std::fs::create_dir(temporary.path().join("nested")).expect("create directory");
@@ -124,36 +123,6 @@ fn real_listener_serves_three_core_interactions_batch_and_write() {
     );
     assert_eq!(read.result, Value::Bytes(b"world".to_vec()));
 
-    let batch_request = BatchRequest {
-        requests: vec![
-            BatchRequestItem {
-                id: "root".into(),
-                request: BatchRequestKind::Observe(ObserveRequest {
-                    path: "/".into(),
-                    depth: 0,
-                }),
-            },
-            BatchRequestItem {
-                id: "tree".into(),
-                request: BatchRequestKind::Observe(ObserveRequest {
-                    path: "/nested".into(),
-                    depth: 1,
-                }),
-            },
-            BatchRequestItem {
-                id: "interface".into(),
-                request: BatchRequestKind::FetchInterface(read_interface_request.clone()),
-            },
-        ],
-    };
-    let response = exchange(
-        address,
-        encode_batch_request(&endpoint, &batch_request, limits).expect("encode batch"),
-    );
-    let batch =
-        success(decode_batch_response(&batch_request, &response, limits).expect("decode batch"));
-    assert_batch_successes(&batch);
-
     let write_interface_request = FetchInterfaceRequest {
         interface: file.interfaces[1].clone(),
     };
@@ -210,6 +179,162 @@ fn real_listener_serves_three_core_interactions_batch_and_write() {
         .expect("listener exits cleanly");
 }
 
+#[test]
+fn real_listener_keeps_route_method_and_malformed_body_boundaries_distinct() {
+    let temporary = tempdir().expect("temporary root");
+    let mut config = ServerConfig::for_root(temporary.path());
+    config.limits.wire = Limits::new(64, 4_096, 64).expect("wire limits");
+    let bound = Arc::new(
+        WipFsServer::new(config)
+            .expect("build server")
+            .bind()
+            .expect("bind"),
+    );
+    let address = bound.local_addr();
+    let shutdown = Arc::new(AtomicBool::new(false));
+    let worker = {
+        let bound = Arc::clone(&bound);
+        let shutdown = Arc::clone(&shutdown);
+        thread::spawn(move || bound.serve_until(shutdown))
+    };
+
+    for uri in [
+        "/wip/v1/unknown",
+        "/wip/v1/batch",
+        "/wip/v1/observe?unexpected=true",
+        "/wip/v1/observe/extra",
+    ] {
+        let response = exchange(address, json_request(http::Method::POST, uri, b"{}"));
+        assert_eq!(response.status(), http::StatusCode::NOT_FOUND);
+        assert!(response.body().is_empty());
+        assert!(!response.headers().contains_key(http::header::CONTENT_TYPE));
+        assert!(!response.headers().contains_key(http::header::ALLOW));
+    }
+
+    let wrong_method = exchange(
+        address,
+        json_request(http::Method::GET, "/wip/v1/observe", b""),
+    );
+    assert_eq!(wrong_method.status(), http::StatusCode::METHOD_NOT_ALLOWED);
+    assert_eq!(wrong_method.headers()[http::header::ALLOW], "POST");
+    assert!(wrong_method.body().is_empty());
+    assert!(
+        !wrong_method
+            .headers()
+            .contains_key(http::header::CONTENT_TYPE)
+    );
+
+    let mut unsupported_coding = json_request(
+        http::Method::POST,
+        "/wip/v1/observe",
+        br#"{"path":"/","depth":0}"#,
+    );
+    unsupported_coding
+        .headers_mut()
+        .insert(http::header::CONTENT_ENCODING, "gzip".parse().unwrap());
+    let unsupported_coding = exchange(address, unsupported_coding);
+    assert_eq!(
+        unsupported_coding.status(),
+        http::StatusCode::UNSUPPORTED_MEDIA_TYPE
+    );
+    assert!(unsupported_coding.body().is_empty());
+    assert!(
+        !unsupported_coding
+            .headers()
+            .contains_key(http::header::CONTENT_TYPE)
+    );
+
+    let malformed = exchange(
+        address,
+        json_request(http::Method::POST, "/wip/v1/observe", b"{"),
+    );
+    assert_eq!(malformed.status(), http::StatusCode::BAD_REQUEST);
+    assert_eq!(
+        malformed.headers()[http::header::CONTENT_TYPE],
+        JSON_CONTENT_TYPE
+    );
+    assert!(
+        std::str::from_utf8(malformed.body())
+            .expect("UTF-8 error envelope")
+            .contains("\"invalid_request\"")
+    );
+
+    let oversized = exchange(
+        address,
+        json_request(http::Method::POST, "/wip/v1/observe", &[b'x'; 65]),
+    );
+    assert_eq!(oversized.status(), http::StatusCode::PAYLOAD_TOO_LARGE);
+    assert!(oversized.body().is_empty());
+    assert!(!oversized.headers().contains_key(http::header::CONTENT_TYPE));
+
+    let mut header_only = TcpStream::connect(address).expect("connect header-only client");
+    header_only
+        .set_read_timeout(Some(Duration::from_secs(1)))
+        .expect("set header-only timeout");
+    write!(
+        header_only,
+        "POST /wip/v1/observe HTTP/1.1\r\nHost: localhost\r\nContent-Type: application/json\r\nContent-Length: 65\r\n\r\n"
+    )
+    .expect("write oversized request head");
+    header_only.flush().expect("flush oversized request head");
+    let mut raw = Vec::new();
+    header_only
+        .read_to_end(&mut raw)
+        .expect("read immediate limit response");
+    assert!(raw.starts_with(b"HTTP/1.1 413 "));
+    assert!(raw.ends_with(b"\r\n\r\n"));
+    assert!(
+        !raw.windows(b"resource_limit_exceeded".len())
+            .any(|window| { window == b"resource_limit_exceeded" })
+    );
+
+    shutdown.store(true, Ordering::Release);
+    worker
+        .join()
+        .expect("join listener")
+        .expect("listener exits cleanly");
+}
+
+#[test]
+fn raw_decoder_limits_are_transport_failures() {
+    let temporary = tempdir().expect("temporary root");
+    let mut config = ServerConfig::for_root(temporary.path());
+    config.limits.wire = Limits::new(4_096, 4_096, 8).expect("wire limits");
+    let server = WipFsServer::new(config).expect("build server");
+
+    let nested = br#"{"path":[[[[[[[[["/"]]]]]]]]],"depth":0}"#;
+    let response = server.handle_http(json_request(http::Method::POST, "/wip/v1/observe", nested));
+    assert_eq!(response.status(), http::StatusCode::PAYLOAD_TOO_LARGE);
+    assert!(response.body().is_empty());
+    assert!(!response.headers().contains_key(http::header::CONTENT_TYPE));
+}
+
+#[test]
+fn logical_observation_limit_remains_protocol_resource_failure() {
+    let temporary = tempdir().expect("temporary root");
+    let mut config = ServerConfig::for_root(temporary.path());
+    config.limits.max_observation_depth = 0;
+    let limits = config.limits.wire;
+    let server = WipFsServer::new(config).expect("build server");
+    let endpoint = Endpoint::parse("http://localhost/wip").expect("endpoint");
+    let request = ObserveRequest {
+        path: "/".into(),
+        depth: 1,
+    };
+
+    let response = server.handle_http(
+        encode_observe_request(&endpoint, &request, limits).expect("encode observation"),
+    );
+    assert_eq!(response.status(), http::StatusCode::UNPROCESSABLE_ENTITY);
+    assert!(matches!(
+        decode_observe_response(&request, &response, limits).expect("decode logical limit"),
+        DecodedResponse::ProtocolFailure {
+            error,
+            status_mismatch: None,
+        } if error.code == ProtocolErrorCode::ResourceLimitExceeded
+    ));
+}
+
 #[test]
 fn stalled_request_body_times_out_and_releases_the_only_worker() {
     let temporary = tempdir().expect("temporary root");
@@ -281,37 +406,6 @@ fn stalled_request_body_times_out_and_releases_the_only_worker() {
         .expect("listener exits cleanly");
 }
 
-#[test]
-fn batch_keeps_known_malformed_arguments_item_local() {
-    let temporary = tempdir().expect("temporary root");
-    let config = ServerConfig::for_root(temporary.path());
-    let limits = config.limits.wire;
-    let server = WipFsServer::new(config).expect("build server");
-    let endpoint = Endpoint::parse("http://localhost/wip").expect("endpoint");
-    let body = br#"{"requests":[{"id":"ok","method":"observe","arguments":{"path":"/","depth":0}},{"id":"bad","method":"observe","arguments":{"path":"/","depth":"bad"}}]}"#;
-    let logical = decode_batch_request(body, limits).expect("decode item-local invalid request");
-    assert!(matches!(
-        logical.requests[1].request,
-        BatchRequestKind::Invalid { .. }
-    ));
-    let request = http::Request::builder()
-        .method(http::Method::POST)
-        .uri(endpoint.route(Route::Batch).as_str())
-        .header(http::header::CONTENT_TYPE, JSON_CONTENT_TYPE)
-        .header(http::header::ACCEPT, "application/json")
-        .body(body.to_vec())
-        .expect("build request");
-    let response = server.handle_http(request);
-    let batch = success(
-        decode_batch_response(&logical, &response, limits).expect("decode mixed batch response"),
-    );
-    assert!(matches!(
-        batch.responses[0].outcome,
-        Ok(BatchSuccess::Observe(_))
-    ));
-    assert!(batch.responses[1].outcome.is_err());
-}
-
 #[test]
 fn call_argument_decoding_does_not_mask_missing_target() {
     let temporary = tempdir().expect("temporary root");
@@ -359,11 +453,11 @@ fn backend_invalid_unicode_path_is_not_found_not_internal() {
 }
 
 #[test]
-fn read_response_size_failure_preserves_non_commit_guarantee() {
+fn read_response_size_failure_is_transport_local() {
     let temporary = tempdir().expect("temporary root");
     std::fs::write(temporary.path().join("large"), vec![b'x'; 2_000]).expect("write file");
     let mut config = ServerConfig::for_root(temporary.path());
-    config.limits.wire = Limits::new(4_096, 1_024, 64, 64).expect("wire limits");
+    config.limits.wire = Limits::new(4_096, 1_024, 64).expect("wire limits");
     let limits = config.limits.wire;
     let server = WipFsServer::new(config).expect("build server");
     let endpoint = Endpoint::parse("http://localhost/wip").expect("endpoint");
@@ -406,30 +500,15 @@ fn read_response_size_failure_preserves_non_commit_guarantee() {
         encode_call_operation_request(&endpoint, &call, &interface.descriptor, limits)
             .expect("encode read call"),
     );
-    assert_eq!(response.status(), http::StatusCode::PAYLOAD_TOO_LARGE);
+    assert_eq!(response.status(), http::StatusCode::INTERNAL_SERVER_ERROR);
-    match decode_call_operation_response(&call, &interface.descriptor, &response, limits)
+    assert!(response.body().is_empty());
-        .expect("decode resource failure")
+    assert!(!response.headers().contains_key(http::header::CONTENT_TYPE));
-    {
-        DecodedResponse::ProtocolFailure { error, .. } => {
-            assert_eq!(error.code, ProtocolErrorCode::ResourceLimitExceeded);
-        }
-        DecodedResponse::Success(_) => panic!("oversized read response must fail"),
-    }
-}
-
-fn assert_batch_successes(batch: &BatchResponse) {
-    assert_eq!(batch.responses.len(), 3);
     assert!(matches!(
-        batch.responses[0].outcome,
+        decode_call_operation_response(&call, &interface.descriptor, &response, limits)
-        Ok(BatchSuccess::Observe(_))
+            .expect_err("oversized representation is not a protocol failure"),
-    ));
+        ClientResponseError::TransportBinding(failure)
-    assert!(matches!(
+            if failure.status == http::StatusCode::INTERNAL_SERVER_ERROR
-        batch.responses[1].outcome,
+                && failure.kind == TransportFailureKind::HttpStatus
-        Ok(BatchSuccess::Observe(_))
-    ));
-    assert!(matches!(
-        batch.responses[2].outcome,
-        Ok(BatchSuccess::FetchInterface(_))
     ));
 }
 
@@ -440,6 +519,16 @@ fn success<T>(response: DecodedResponse<T>) -> T {
     }
 }
 
+fn json_request(method: http::Method, uri: &str, body: &[u8]) -> http::Request<Vec<u8>> {
+    http::Request::builder()
+        .method(method)
+        .uri(uri)
+        .header(http::header::CONTENT_TYPE, JSON_CONTENT_TYPE)
+        .header(http::header::ACCEPT, "application/json")
+        .body(body.to_vec())
+        .expect("build JSON request")
+}
+
 fn exchange(address: SocketAddr, request: http::Request<Vec<u8>>) -> http::Response<Vec<u8>> {
     let mut stream = TcpStream::connect(address).expect("connect listener");
     stream

crates/wip-host/Cargo.toml

@@ -1,13 +1,17 @@
 [package]
 name = "wip-host"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Host-side object publication and operation dispatch for WIP"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-host"
 
 [dependencies]
-wip-interface = { path = "../wip-interface" }
+wip-interface.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true
 
 [dev-dependencies]
 trybuild = "1"

crates/wip-host/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
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crates/wip-host/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-host/README.md

@@ -0,0 +1,15 @@
+# wip-host
+
+Framework-independent Host publication and operation dispatch for the Web Interface Protocol (WIP).
+
+`wip-host` registers generated interfaces, explicitly publishes them on request-scoped objects, validates object and interface preconditions, and performs interface-qualified operation dispatch against one host-owned instance. Backend transactions, persistence, and network serving remain application responsibilities.
+
+```toml
+[dependencies]
+wip-host = "0.1.0"
+wip-interface = "0.1.0"
+```
+
+See the [API documentation](https://docs.rs/wip-host) for publication, provider, execution-context, and effect-guarantee boundaries.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-host/src/lib.rs

@@ -211,6 +211,17 @@ pub struct InterfaceObservation {
 }
 
 impl InterfaceObservation {
+    /// Restricts this effective view to visible operations and reachable types.
+    ///
+    /// Registry artifacts are unchanged. When operations are removed, interface-
+    /// wide documentation is omitted because it may describe hidden operations.
+    /// Providers must use the same predicate for publication and fetch.
+    #[must_use]
+    pub fn project_operations(mut self, visible: impl Fn(&str) -> bool) -> Self {
+        restrict_descriptor(&mut self.descriptor, visible);
+        self
+    }
+
     /// Converts this host observation to a validated canonical protocol response.
     ///
     /// A Host-side response construction failure is returned as `Internal`; it is
@@ -449,6 +460,60 @@ pub trait WipObject {
     }
 }
 
+fn restrict_descriptor(descriptor: &mut InterfaceDescriptor, visible: impl Fn(&str) -> bool) {
+    let count = descriptor.operations.len();
+    descriptor
+        .operations
+        .retain(|operation| visible(&operation.name));
+    if descriptor.operations.len() == count {
+        return;
+    }
+    descriptor.documentation = None;
+    let mut used = HashSet::new();
+    fn references(expression: &wip_protocol::TypeExpr, used: &mut HashSet<String>) {
+        use wip_protocol::TypeExpr;
+        match expression {
+            TypeExpr::Named { name } => {
+                used.insert(name.clone());
+            }
+            TypeExpr::Record { fields } => {
+                for field in fields {
+                    references(&field.r#type, used);
+                }
+            }
+            TypeExpr::List { items } => references(items, used),
+            TypeExpr::Union { cases } => {
+                for case in cases {
+                    if let Some(payload) = &case.payload {
+                        references(payload, used);
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+    for operation in &descriptor.operations {
+        for parameter in &operation.parameters {
+            references(&parameter.r#type, &mut used);
+        }
+        references(&operation.returns.r#type, &mut used);
+    }
+    loop {
+        let before = used.len();
+        for declaration in &descriptor.types {
+            if used.contains(&declaration.name) {
+                references(&declaration.definition, &mut used);
+            }
+        }
+        if before == used.len() {
+            break;
+        }
+    }
+    descriptor
+        .types
+        .retain(|declaration| used.contains(&declaration.name));
+}
+
 type DispatchFn<T> = fn(&T, &str, BTreeMap<String, Value>) -> Result<Value, DispatchError>;
 
 struct BoundInterface<T> {
@@ -502,6 +567,46 @@ impl<T: WipObject> PublishedObject<T> {
         Ok(self)
     }
 
+    /// Restricts a publication to an ordered interface/operation view.
+    ///
+    /// This never adds implementations or changes codecs. The provider must use
+    /// the identical operation predicate for `fetch_interface`, and keep the
+    /// effective view stable for the lifetime of its references. Filtered
+    /// descriptors are scoped to that view, not mutations of registry artifacts.
+    pub fn project(
+        mut self,
+        interfaces: &[InterfaceRef],
+        visible: impl Fn(&InterfaceRef, &str) -> bool,
+    ) -> Result<Self, PublicationError> {
+        let mut projected = Vec::with_capacity(interfaces.len());
+        for reference in interfaces {
+            if projected
+                .iter()
+                .any(|bound: &BoundInterface<T>| &bound.artifact.reference == reference)
+            {
+                return Err(PublicationError::DuplicateInterface(reference.clone()));
+            }
+            let Some(index) = self
+                .interfaces
+                .iter()
+                .position(|bound| &bound.artifact.reference == reference)
+            else {
+                return Err(PublicationError::UnexposedInterface(reference.clone()));
+            };
+            let mut bound = self.interfaces.remove(index);
+            let mut descriptor = bound.artifact.descriptor.clone();
+            restrict_descriptor(&mut descriptor, |operation| visible(reference, operation));
+            bound.artifact = Arc::new(InterfaceArtifact {
+                reference: reference.clone(),
+                descriptor,
+                validator: bound.artifact.validator.clone(),
+            });
+            projected.push(bound);
+        }
+        self.interfaces = projected;
+        Ok(self)
+    }
+
     /// Returns the host-private implementation without projecting its fields.
     #[must_use]
     pub fn implementation(&self) -> &T {
@@ -782,6 +887,15 @@ pub enum OperationAttempt {
 }
 
 impl OperationAttempt {
+    /// Rejects a provider precondition before typed implementation invocation.
+    ///
+    /// Only use this before dispatch starts; post-invocation failures require
+    /// an explicit effect disposition. The diagnostic is intentionally generic.
+    #[must_use]
+    pub fn reject(kind: CallErrorKind) -> Self {
+        Self::NotStarted(CallError::new(kind, "provider precondition failed"))
+    }
+
     /// Marks a post-invocation failure as fully rolled back.
     ///
     /// Successful attempts and pre-dispatch failures are returned unchanged.
@@ -1016,11 +1130,18 @@ pub trait ObjectProvider {
 pub enum PublicationError {
     /// The same opaque interface reference was exposed more than once.
     DuplicateInterface(InterfaceRef),
+    /// Projection attempted to add an interface without an implementation.
+    UnexposedInterface(InterfaceRef),
 }
 
 impl Display for PublicationError {
     fn fmt(&self, formatter: &mut Formatter<'_>) -> fmt::Result {
         match self {
+            Self::UnexposedInterface(reference) => write!(
+                formatter,
+                "interface `{}` has no implementation",
+                reference.as_str()
+            ),
             Self::DuplicateInterface(reference) => write!(
                 formatter,
                 "interface `{}` is already exposed by this object",
@@ -1032,6 +1153,70 @@ impl Display for PublicationError {
 
 impl Error for PublicationError {}
 
+#[cfg(test)]
+mod projection_tests {
+    use super::*;
+    use wip_protocol::{
+        Documentation, OperationDeclaration, ReturnDeclaration, TypeDeclaration, TypeExpr,
+    };
+
+    #[test]
+    fn operation_views_prune_hidden_types_and_documentation_without_mutating_registry() {
+        let named = |name: &str| TypeExpr::Named { name: name.into() };
+        let operation = |name: &str, returns| OperationDeclaration {
+            name: name.into(),
+            documentation: None,
+            parameters: Vec::new(),
+            returns: ReturnDeclaration {
+                documentation: None,
+                r#type: returns,
+            },
+        };
+        let declaration = |name: &str, definition| TypeDeclaration {
+            name: name.into(),
+            documentation: None,
+            definition,
+        };
+        let descriptor = InterfaceDescriptor {
+            format: "wip/1".into(),
+            documentation: Some(Documentation {
+                summary: "contains hidden operation details".into(),
+                details: None,
+            }),
+            operations: vec![
+                operation("visible", named("Public")),
+                operation("secret", named("Secret")),
+            ],
+            types: vec![
+                declaration(
+                    "Public",
+                    TypeExpr::List {
+                        items: Box::new(named("Shared")),
+                    },
+                ),
+                declaration("Shared", TypeExpr::String),
+                declaration("Secret", TypeExpr::Bytes),
+            ],
+        };
+        let mut projected = descriptor.clone();
+        restrict_descriptor(&mut projected, |operation| operation == "visible");
+        assert_eq!(projected.operations.len(), 1);
+        assert!(projected.documentation.is_none());
+        assert_eq!(
+            projected
+                .types
+                .iter()
+                .map(|declaration| declaration.name.as_str())
+                .collect::<Vec<_>>(),
+            vec!["Public", "Shared"]
+        );
+        assert_eq!(descriptor.types.len(), 3);
+        restrict_descriptor(&mut projected, |_| false);
+        assert!(projected.types.is_empty());
+        assert!(projected.operations.is_empty());
+    }
+}
+
 /// Stable Host dispatch failure kind.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum CallErrorKind {

crates/wip-host/tests/host.rs

@@ -14,6 +14,62 @@ use wip_interface::{
 };
 use wip_protocol::ProtocolErrorCode;
 
+#[test]
+fn principal_projection_orders_subsets_and_rejects_unimplemented_or_duplicate_tokens() {
+    let mut registry = InterfaceRegistry::new();
+    let read = registry.register(ReaderDefinition, None).unwrap();
+    let write = registry.register(WriterDefinition, None).unwrap();
+    let hidden = registry.register(HiddenDefinition, None).unwrap();
+    let publication = || {
+        PublishedObject::new(Document::open("document", None, Rc::new(Cell::new(0))))
+            .expose(&read)
+            .unwrap()
+            .expose(&write)
+            .unwrap()
+    };
+    let projected = publication()
+        .project(
+            &[write.reference().clone(), read.reference().clone()],
+            |_, operation| operation == "label",
+        )
+        .unwrap();
+    assert_eq!(
+        projected.protocol_object().interfaces,
+        vec![write.reference().as_str(), read.reference().as_str()]
+    );
+    assert!(
+        publication()
+            .project(&[hidden.reference().clone()], |_, _| true)
+            .is_err()
+    );
+    assert!(
+        publication()
+            .project(
+                &[read.reference().clone(), read.reference().clone()],
+                |_, _| true
+            )
+            .is_err()
+    );
+    assert!(
+        publication()
+            .project(&[], |_, _| true)
+            .unwrap()
+            .protocol_object()
+            .interfaces
+            .is_empty()
+    );
+    let full = registry.fetch_interface(read.reference().as_str()).unwrap();
+    let filtered = full
+        .clone()
+        .project_operations(|operation| operation == "label");
+    assert_eq!(filtered.descriptor.operations.len(), 1);
+    assert_eq!(full.descriptor.operations.len(), 3);
+    assert_eq!(
+        registry.fetch_interface(read.reference().as_str()).unwrap(),
+        full
+    );
+}
+
 #[interface]
 pub trait Reader {
     /// Returns the reader-qualified label.

crates/wip-http/Cargo.toml

@@ -1,9 +1,13 @@
 [package]
 name = "wip-http"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Framework-independent standard WIP over HTTP v1 binding"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-http"
 
 [dependencies]
 base64 = "0.22"
@@ -11,4 +15,4 @@ http = "1"
 serde = "1"
 serde_json = "1"
 url = "2"
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true

crates/wip-http/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
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+   limitations under the License.

crates/wip-http/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-http/README.md

@@ -0,0 +1,31 @@
+# wip-http
+
+Framework-independent WIP over HTTP v1 endpoint, route, JSON codec, and response-classification support.
+
+The crate maps the three WIP Core interactions to fixed HTTP routes and strict UTF-8 JSON representations. It constructs and validates `http` request and response values but deliberately performs no network I/O and does not define TLS, authentication, proxy, or connection policy.
+
+```toml
+[dependencies]
+wip-http = "0.1.0"
+```
+
+```rust
+use wip_http::wip_protocol::ObserveRequest;
+use wip_http::{Endpoint, Limits, encode_observe_request};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let endpoint = Endpoint::parse("https://example.test/wip")?;
+    let limits = Limits::new(64 * 1024, 1024 * 1024, 64)?;
+    let request = encode_observe_request(
+        &endpoint,
+        &ObserveRequest { path: "/".into(), depth: 0 },
+        limits,
+    )?;
+    assert_eq!(request.uri(), "https://example.test/wip/v1/observe");
+    Ok(())
+}
+```
+
+See the [API documentation](https://docs.rs/wip-http) for codec and failure-boundary details.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-http/src/batch.rs

@@ -1,570 +0,0 @@
-use std::collections::{BTreeMap, BTreeSet};
-
-use http::header::{ACCEPT, CONTENT_TYPE};
-use http::{Method, Request, Response, StatusCode};
-use serde_json::{Map, Value as Json};
-use wip_protocol::{
-    FetchInterfaceRequest, FetchInterfaceResponse, INTERFACE_FORMAT_V1, ObserveRequest,
-    ObserveResponse, ProtocolError, ProtocolErrorCode, ProtocolInteraction,
-};
-
-use crate::response::{self, DecodedResponse};
-use crate::{
-    BodyKind, ClientResponseError, CodecError, EncodeHttpError, Endpoint, InvalidResponseKind,
-    JSON_CONTENT_TYPE, Limits, ResourceLimitKind, Route, is_json_content_type, json,
-};
-
-/// A retrieval method accepted by the standard v1 batch endpoint.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum BatchMethod {
-    /// Observe one object and its indexable descendants.
-    Observe,
-    /// Fetch one interface descriptor.
-    FetchInterface,
-}
-
-impl BatchMethod {
-    fn name(self) -> &'static str {
-        match self {
-            Self::Observe => "observe",
-            Self::FetchInterface => "fetch_interface",
-        }
-    }
-
-    fn interaction(self) -> ProtocolInteraction {
-        match self {
-            Self::Observe => ProtocolInteraction::Observe,
-            Self::FetchInterface => ProtocolInteraction::FetchInterface,
-        }
-    }
-}
-
-/// One retrieval interaction accepted by the standard v1 batch endpoint.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum BatchRequestKind {
-    /// Observe one object and its indexable descendants.
-    Observe(ObserveRequest),
-    /// Fetch one interface descriptor.
-    FetchInterface(FetchInterfaceRequest),
-    /// A known method whose `arguments` are not a valid logical request.
-    Invalid {
-        /// Method that was successfully identified from the item envelope.
-        method: BatchMethod,
-        /// Item-local `invalid_request` to return without rejecting other items.
-        error: ProtocolError,
-    },
-}
-
-impl BatchRequestKind {
-    fn interaction(&self) -> ProtocolInteraction {
-        match self {
-            Self::Observe(_) => ProtocolInteraction::Observe,
-            Self::FetchInterface(_) => ProtocolInteraction::FetchInterface,
-            Self::Invalid { method, .. } => method.interaction(),
-        }
-    }
-}
-
-/// One uniquely identified batch subrequest.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct BatchRequestItem {
-    /// Identifier used only to correlate the corresponding subresponse.
-    pub id: String,
-    /// Retrieval interaction and arguments.
-    pub request: BatchRequestKind,
-}
-
-/// A standard v1 batch request.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct BatchRequest {
-    /// Independent subrequests. Identifiers must be unique.
-    pub requests: Vec<BatchRequestItem>,
-}
-
-/// Successful result of one batch item.
-#[derive(Debug, Clone, PartialEq)]
-pub enum BatchSuccess {
-    /// Successful `observe` result.
-    Observe(ObserveResponse),
-    /// Successful `fetch_interface` result.
-    FetchInterface(FetchInterfaceResponse),
-}
-
-/// One batch subresponse, correlated by `id` rather than array position.
-#[derive(Debug, Clone, PartialEq)]
-pub struct BatchResponseItem {
-    /// Identifier copied from its subrequest.
-    pub id: String,
-    /// Direct interaction result or canonical item-local protocol failure.
-    pub outcome: Result<BatchSuccess, ProtocolError>,
-}
-
-/// A valid standard v1 batch response.
-#[derive(Debug, Clone, PartialEq)]
-pub struct BatchResponse {
-    /// Exactly one response for each requested identifier, in any order.
-    pub responses: Vec<BatchResponseItem>,
-}
-
-fn validate_ids<'a>(ids: impl Iterator<Item = &'a str>, maximum: usize) -> Result<(), CodecError> {
-    let mut seen = BTreeSet::new();
-    let mut count = 0;
-    for id in ids {
-        count += 1;
-        if !seen.insert(id) {
-            return Err(CodecError::DuplicateBatchId { id: id.into() });
-        }
-    }
-    if count > maximum {
-        return Err(CodecError::TooManyBatchItems {
-            actual: count,
-            maximum,
-        });
-    }
-    Ok(())
-}
-
-fn request_item_to_json(item: &BatchRequestItem) -> Result<Json, CodecError> {
-    let (method, arguments) = match &item.request {
-        BatchRequestKind::Observe(value) => ("observe", json::observe_request_to_json(value)),
-        BatchRequestKind::FetchInterface(value) => (
-            "fetch_interface",
-            json::fetch_interface_request_to_json(value),
-        ),
-        BatchRequestKind::Invalid { .. } => {
-            return Err(CodecError::InvalidField {
-                field: "requests".into(),
-                reason: "item-local invalid requests cannot be encoded as client requests".into(),
-            });
-        }
-    };
-    Ok(serde_json::json!({"id": item.id, "method": method, "arguments": arguments}))
-}
-
-fn request_to_json(request: &BatchRequest, limits: Limits) -> Result<Json, CodecError> {
-    validate_ids(
-        request.requests.iter().map(|item| item.id.as_str()),
-        limits.max_batch_items,
-    )?;
-    for item in &request.requests {
-        match &item.request {
-            BatchRequestKind::Observe(value) => value.validate()?,
-            BatchRequestKind::FetchInterface(_) | BatchRequestKind::Invalid { .. } => {}
-        }
-    }
-    let requests = request
-        .requests
-        .iter()
-        .map(request_item_to_json)
-        .collect::<Result<Vec<_>, _>>()?;
-    Ok(serde_json::json!({"requests": requests}))
-}
-
-fn request_from_json(value: &Json, limits: Limits) -> Result<BatchRequest, CodecError> {
-    let fields = exact_object(value, "batch", &["requests"])?;
-    let values = array(required(fields, "requests")?, "requests")?;
-    if values.len() > limits.max_batch_items {
-        return Err(CodecError::TooManyBatchItems {
-            actual: values.len(),
-            maximum: limits.max_batch_items,
-        });
-    }
-    let mut requests = Vec::with_capacity(values.len());
-    for (index, value) in values.iter().enumerate() {
-        let field = format!("requests[{index}]");
-        let fields = exact_object(value, &field, &["id", "method", "arguments"])?;
-        let id = string(required(fields, "id")?, &format!("{field}.id"))?;
-        let method_name = string(required(fields, "method")?, &format!("{field}.method"))?;
-        let arguments = required(fields, "arguments")?;
-        let method = match method_name.as_str() {
-            "observe" => BatchMethod::Observe,
-            "fetch_interface" => BatchMethod::FetchInterface,
-            _ => {
-                return Err(CodecError::InvalidField {
-                    field: format!("{field}.method"),
-                    reason: "batch supports only observe and fetch_interface".into(),
-                });
-            }
-        };
-        let decoded = match method {
-            BatchMethod::Observe => {
-                json::observe_request_from_json(arguments).map(BatchRequestKind::Observe)
-            }
-            BatchMethod::FetchInterface => json::fetch_interface_request_from_json(arguments)
-                .map(BatchRequestKind::FetchInterface),
-        };
-        let request = decoded.unwrap_or_else(|error| BatchRequestKind::Invalid {
-            method,
-            error: ProtocolError {
-                code: ProtocolErrorCode::InvalidRequest,
-                message: format!("invalid {} arguments: {error}", method.name()),
-            },
-        });
-        requests.push(BatchRequestItem { id, request });
-    }
-    validate_ids(
-        requests.iter().map(|item| item.id.as_str()),
-        limits.max_batch_items,
-    )?;
-    Ok(BatchRequest { requests })
-}
-
-/// Encodes a batch request using `POST v1/batch`.
-pub fn encode_batch_request(
-    endpoint: &Endpoint,
-    value: &BatchRequest,
-    limits: Limits,
-) -> Result<Request<Vec<u8>>, EncodeHttpError> {
-    let body = json::serialize(&request_to_json(value, limits)?, BodyKind::Request, limits)?;
-    Ok(Request::builder()
-        .method(Method::POST)
-        .uri(endpoint.route(Route::Batch).as_str())
-        .header(CONTENT_TYPE, JSON_CONTENT_TYPE)
-        .header(ACCEPT, "application/json")
-        .body(body)?)
-}
-
-/// Decodes and validates a batch request body.
-pub fn decode_batch_request(body: &[u8], limits: Limits) -> Result<BatchRequest, CodecError> {
-    let value = json::parse(body, BodyKind::Request, limits)?;
-    request_from_json(&value, limits)
-}
-
-fn success_to_json(success: &BatchSuccess) -> Json {
-    match success {
-        BatchSuccess::Observe(value) => json::observe_response_to_json(value),
-        BatchSuccess::FetchInterface(value) => json::fetch_interface_response_to_json(value),
-    }
-}
-
-fn response_to_json(
-    request: &BatchRequest,
-    response: &BatchResponse,
-    limits: Limits,
-) -> Result<Json, CodecError> {
-    correlate(request, response, limits)?;
-    Ok(serde_json::json!({
-        "responses": response.responses.iter().map(|item| {
-            let mut fields = Map::new();
-            fields.insert("id".into(), Json::String(item.id.clone()));
-            match &item.outcome {
-                Ok(success) => { fields.insert("result".into(), success_to_json(success)); }
-                Err(error) => { fields.insert("error".into(), response::item_error_to_json(error)); }
-            }
-            Json::Object(fields)
-        }).collect::<Vec<_>>()
-    }))
-}
-
-fn correlate(
-    request: &BatchRequest,
-    response: &BatchResponse,
-    limits: Limits,
-) -> Result<(), CodecError> {
-    validate_ids(
-        request.requests.iter().map(|item| item.id.as_str()),
-        limits.max_batch_items,
-    )?;
-    validate_ids(
-        response.responses.iter().map(|item| item.id.as_str()),
-        limits.max_batch_items,
-    )?;
-    let requested: BTreeMap<&str, &BatchRequestKind> = request
-        .requests
-        .iter()
-        .map(|item| (item.id.as_str(), &item.request))
-        .collect();
-    for item in &response.responses {
-        let Some(kind) = requested.get(item.id.as_str()) else {
-            return Err(CodecError::UnexpectedBatchId {
-                id: item.id.clone(),
-            });
-        };
-        match (&item.outcome, *kind) {
-            (Ok(BatchSuccess::Observe(value)), BatchRequestKind::Observe(request)) => {
-                request.validate_response(value)?;
-            }
-            (
-                Ok(BatchSuccess::FetchInterface(value)),
-                BatchRequestKind::FetchInterface(request),
-            ) => {
-                value.validate_for(request)?;
-            }
-            (
-                Err(error),
-                BatchRequestKind::Invalid {
-                    error: expected, ..
-                },
-            ) if error == expected => {}
-            (Err(error), kind)
-                if !matches!(kind, BatchRequestKind::Invalid { .. })
-                    && error.code.is_allowed_for(kind.interaction()) => {}
-            _ => {
-                return Err(CodecError::BatchInteractionMismatch {
-                    id: item.id.clone(),
-                });
-            }
-        }
-    }
-    for item in &request.requests {
-        if !response.responses.iter().any(|other| other.id == item.id) {
-            return Err(CodecError::MissingBatchId {
-                id: item.id.clone(),
-            });
-        }
-    }
-    Ok(())
-}
-
-/// Encodes a valid batch response. Item failures remain inside HTTP 200.
-pub fn encode_batch_response(
-    request: &BatchRequest,
-    value: &BatchResponse,
-    limits: Limits,
-) -> Result<Response<Vec<u8>>, EncodeHttpError> {
-    let body = json::serialize(
-        &response_to_json(request, value, limits)?,
-        BodyKind::Response,
-        limits,
-    )?;
-    Ok(Response::builder()
-        .status(StatusCode::OK)
-        .header(CONTENT_TYPE, JSON_CONTENT_TYPE)
-        .body(body)?)
-}
-
-/// Encodes a top-level batch-envelope failure.
-///
-/// Item-local failures belong in [`BatchResponseItem`]. Only failures that can
-/// reject the batch envelope before item execution are accepted here. A
-/// resource-limit failure defaults to the logical-limit status; use
-/// [`encode_batch_resource_limit_error_response`] when the concrete class is
-/// known.
-pub fn encode_batch_error_response(
-    error: &ProtocolError,
-    limits: Limits,
-) -> Result<Response<Vec<u8>>, EncodeHttpError> {
-    if !matches!(
-        error.code,
-        ProtocolErrorCode::InvalidRequest
-            | ProtocolErrorCode::ResourceLimitExceeded
-            | ProtocolErrorCode::Internal
-    ) {
-        return Err(CodecError::InvalidField {
-            field: "error.code".into(),
-            reason: "code is not valid for a top-level batch failure".into(),
-        }
-        .into());
-    }
-    let body = json::serialize(&response::error_to_json(error), BodyKind::Response, limits)?;
-    Ok(Response::builder()
-        .status(response::status_for_error(error.code))
-        .header(CONTENT_TYPE, JSON_CONTENT_TYPE)
-        .body(body)?)
-}
-
-/// Encodes a class-specific top-level batch `resource_limit_exceeded` failure.
-pub fn encode_batch_resource_limit_error_response(
-    error: &ProtocolError,
-    kind: ResourceLimitKind,
-    limits: Limits,
-) -> Result<Response<Vec<u8>>, EncodeHttpError> {
-    if error.code != ProtocolErrorCode::ResourceLimitExceeded {
-        return Err(CodecError::InvalidField {
-            field: "error.code".into(),
-            reason: "resource-limit encoder requires resource_limit_exceeded".into(),
-        }
-        .into());
-    }
-    let body = json::serialize(&response::error_to_json(error), BodyKind::Response, limits)?;
-    Ok(Response::builder()
-        .status(response::status_for_resource_limit(kind))
-        .header(CONTENT_TYPE, JSON_CONTENT_TYPE)
-        .body(body)?)
-}
-
-fn response_from_json(
-    value: &Json,
-    request: &BatchRequest,
-    limits: Limits,
-) -> Result<BatchResponse, CodecError> {
-    let fields = exact_object(value, "batch", &["responses"])?;
-    let values = array(required(fields, "responses")?, "responses")?;
-    if values.len() > limits.max_batch_items {
-        return Err(CodecError::TooManyBatchItems {
-            actual: values.len(),
-            maximum: limits.max_batch_items,
-        });
-    }
-    let requested: BTreeMap<&str, &BatchRequestKind> = request
-        .requests
-        .iter()
-        .map(|item| (item.id.as_str(), &item.request))
-        .collect();
-    let mut responses = Vec::with_capacity(values.len());
-    for (index, value) in values.iter().enumerate() {
-        let field = format!("responses[{index}]");
-        let fields = object(value, &field)?;
-        for name in fields.keys() {
-            if !["id", "result", "error"].contains(&name.as_str()) {
-                return Err(CodecError::UnknownField {
-                    field: format!("{field}.{name}"),
-                });
-            }
-        }
-        let id = string(required(fields, "id")?, &format!("{field}.id"))?;
-        let Some(kind) = requested.get(id.as_str()) else {
-            return Err(CodecError::UnexpectedBatchId { id });
-        };
-        let outcome = match (fields.get("result"), fields.get("error")) {
-            (Some(_), Some(_)) | (None, None) => {
-                return Err(CodecError::InvalidField {
-                    field,
-                    reason: "batch item must contain exactly one of result or error".into(),
-                });
-            }
-            (None, Some(error)) => {
-                let error = response::item_error_from_json(error)?;
-                match kind {
-                    BatchRequestKind::Invalid {
-                        error: expected, ..
-                    } if error == *expected => {}
-                    BatchRequestKind::Invalid { .. } => {
-                        return Err(CodecError::BatchInteractionMismatch { id });
-                    }
-                    kind if error.code.is_allowed_for(kind.interaction()) => {}
-                    _ => return Err(CodecError::BatchInteractionMismatch { id }),
-                }
-                Err(error)
-            }
-            (Some(result), None) => Ok(match kind {
-                BatchRequestKind::Observe(request) => {
-                    let value = json::observe_response_from_json(result)?;
-                    request.validate_response(&value)?;
-                    BatchSuccess::Observe(value)
-                }
-                BatchRequestKind::FetchInterface(request) => {
-                    let value = json::fetch_interface_response_from_json(result)?;
-                    value.validate_for(request)?;
-                    BatchSuccess::FetchInterface(value)
-                }
-                BatchRequestKind::Invalid { .. } => {
-                    return Err(CodecError::BatchInteractionMismatch { id });
-                }
-            }),
-        };
-        responses.push(BatchResponseItem { id, outcome });
-    }
-    let response = BatchResponse { responses };
-    correlate(request, &response, limits)?;
-    Ok(response)
-}
-
-/// Decodes a batch response, including item-local failures within HTTP 200.
-pub fn decode_batch_response<B: AsRef<[u8]>>(
-    request: &BatchRequest,
-    value: &Response<B>,
-    limits: Limits,
-) -> Result<DecodedResponse<BatchResponse>, ClientResponseError> {
-    let valid_content_type = value
-        .headers()
-        .get(CONTENT_TYPE)
-        .and_then(|value| value.to_str().ok())
-        .is_some_and(is_json_content_type);
-    if !valid_content_type {
-        if value.status().is_success() {
-            return Err(ClientResponseError::invalid(
-                InvalidResponseKind::InvalidBatch,
-                "missing or non-UTF-8 application/json Content-Type",
-            ));
-        }
-        return Err(response::transport_failure(value.status()));
-    }
-    let decoded = response::decode(
-        value.status(),
-        value.body().as_ref(),
-        ProtocolInteraction::Observe,
-        limits,
-        |json| response_from_json(json, request, limits),
-    )
-    .map_err(|error| match error {
-        ClientResponseError::InvalidResponse { detail, .. } => {
-            ClientResponseError::invalid(InvalidResponseKind::InvalidBatch, detail)
-        }
-        other => other,
-    })?;
-    if let DecodedResponse::ProtocolFailure { error, .. } = &decoded
-        && !matches!(
-            error.code,
-            ProtocolErrorCode::InvalidRequest
-                | ProtocolErrorCode::ResourceLimitExceeded
-                | ProtocolErrorCode::Internal
-        )
-    {
-        return Err(ClientResponseError::invalid(
-            InvalidResponseKind::InvalidBatch,
-            "protocol code is not valid for a top-level batch failure",
-        ));
-    }
-    if let DecodedResponse::Success(success) = &decoded {
-        for item in &success.responses {
-            if let Ok(BatchSuccess::FetchInterface(interface)) = &item.outcome
-                && interface.descriptor.format != INTERFACE_FORMAT_V1
-            {
-                return Err(ClientResponseError::UnsupportedDescriptorFormat {
-                    format: interface.descriptor.format.clone(),
-                });
-            }
-        }
-    }
-    Ok(decoded)
-}
-
-fn object<'a>(value: &'a Json, field: &str) -> Result<&'a Map<String, Json>, CodecError> {
-    value.as_object().ok_or_else(|| CodecError::InvalidField {
-        field: field.into(),
-        reason: "expected object".into(),
-    })
-}
-
-fn exact_object<'a>(
-    value: &'a Json,
-    field: &str,
-    allowed: &[&str],
-) -> Result<&'a Map<String, Json>, CodecError> {
-    let fields = object(value, field)?;
-    for name in fields.keys() {
-        if !allowed.contains(&name.as_str()) {
-            return Err(CodecError::UnknownField {
-                field: format!("{field}.{name}"),
-            });
-        }
-    }
-    Ok(fields)
-}
-
-fn required<'a>(fields: &'a Map<String, Json>, name: &str) -> Result<&'a Json, CodecError> {
-    fields
-        .get(name)
-        .ok_or_else(|| CodecError::MissingField { field: name.into() })
-}
-
-fn string(value: &Json, field: &str) -> Result<String, CodecError> {
-    value
-        .as_str()
-        .map(str::to_owned)
-        .ok_or_else(|| CodecError::InvalidField {
-            field: field.into(),
-            reason: "expected string".into(),
-        })
-}
-
-fn array<'a>(value: &'a Json, field: &str) -> Result<&'a [Json], CodecError> {
-    value
-        .as_array()
-        .map(Vec::as_slice)
-        .ok_or_else(|| CodecError::InvalidField {
-            field: field.into(),
-            reason: "expected array".into(),
-        })
-}

crates/wip-http/src/codec.rs

@@ -1,7 +1,7 @@
 use std::error::Error;
 use std::fmt::{self, Display, Formatter};
 
-use http::header::{ACCEPT, CONTENT_TYPE};
+use http::header::{ACCEPT, CONTENT_ENCODING, CONTENT_TYPE};
 use http::{HeaderMap, Method, Request, Response, StatusCode};
 use wip_protocol::{
     CallOperationRequest, CallOperationResponse, FetchInterfaceRequest, FetchInterfaceResponse,
@@ -12,7 +12,7 @@ use wip_protocol::{
 use crate::response::{self, DecodedResponse};
 use crate::{
     BodyKind, ClientResponseError, CodecError, Endpoint, InvalidResponseKind, JSON_CONTENT_TYPE,
-    Limits, ResourceLimitKind, Route, json,
+    Limits, Route, json,
 };
 
 fn request(
@@ -36,6 +36,9 @@ fn response(status: StatusCode, body: Vec<u8>) -> Result<Response<Vec<u8>>, http
 }
 
 fn require_response_content_type<B>(response: &Response<B>) -> Result<(), ClientResponseError> {
+    if !has_supported_content_coding(response.headers()) {
+        return Err(response::unsupported_content_coding(response.status()));
+    }
     let valid = response
         .headers()
         .get(CONTENT_TYPE)
@@ -181,9 +184,11 @@ fn accepts_json(headers: &HeaderMap) -> bool {
 /// A failure while validating inbound HTTP request metadata.
 #[derive(Debug)]
 pub enum RequestMetadataError {
-    /// The method or route does not match the selected WIP interaction.
+    /// The request URI does not exactly identify the selected standard route.
-    InvalidRequest(CodecError),
+    NotFound,
-    /// The request body does not use UTF-8 `application/json`.
+    /// A known standard route was requested with a method other than `POST`.
+    MethodNotAllowed,
+    /// The request body does not use UTF-8 `application/json` or identity coding.
     UnsupportedMediaType,
     /// The request's `Accept` metadata excludes `application/json`.
     NotAcceptable,
@@ -194,32 +199,47 @@ impl RequestMetadataError {
     #[must_use]
     pub const fn status(&self) -> StatusCode {
         match self {
-            Self::InvalidRequest(_) => StatusCode::BAD_REQUEST,
+            Self::NotFound => StatusCode::NOT_FOUND,
+            Self::MethodNotAllowed => StatusCode::METHOD_NOT_ALLOWED,
             Self::UnsupportedMediaType => StatusCode::UNSUPPORTED_MEDIA_TYPE,
             Self::NotAcceptable => StatusCode::NOT_ACCEPTABLE,
         }
     }
+
+    /// Returns the value for an `Allow` response header, when required.
+    #[must_use]
+    pub const fn allow(&self) -> Option<&'static str> {
+        match self {
+            Self::MethodNotAllowed => Some("POST"),
+            Self::NotFound | Self::UnsupportedMediaType | Self::NotAcceptable => None,
+        }
+    }
 }
 
 impl Display for RequestMetadataError {
     fn fmt(&self, formatter: &mut Formatter<'_>) -> fmt::Result {
         match self {
-            Self::InvalidRequest(error) => error.fmt(formatter),
+            Self::NotFound => formatter.write_str("request URI is not a standard WIP route"),
+            Self::MethodNotAllowed => formatter.write_str("standard WIP routes require POST"),
             Self::UnsupportedMediaType => {
-                formatter.write_str("expected UTF-8 application/json Content-Type")
+                formatter.write_str("expected identity-coded UTF-8 application/json Content-Type")
             }
             Self::NotAcceptable => formatter.write_str("request does not accept application/json"),
         }
     }
 }
 
-impl Error for RequestMetadataError {
+impl Error for RequestMetadataError {}
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
+
-        match self {
+pub(crate) fn has_supported_content_coding(headers: &HeaderMap) -> bool {
-            Self::InvalidRequest(error) => Some(error),
+    headers.get_all(CONTENT_ENCODING).iter().all(|value| {
-            Self::UnsupportedMediaType | Self::NotAcceptable => None,
+        value.to_str().is_ok_and(|value| {
-        }
+            let mut codings = value.split(',').map(str::trim);
-    }
+            let first = codings.next();
+            first.is_some_and(|coding| coding.eq_ignore_ascii_case("identity"))
+                && codings.all(|coding| coding.eq_ignore_ascii_case("identity"))
+        })
+    })
 }
 
 /// Validates mandatory HTTP metadata for an inbound WIP request.
@@ -233,29 +253,19 @@ pub fn validate_http_request<B>(
     route: Route,
     value: &Request<B>,
 ) -> Result<(), RequestMetadataError> {
-    if value.method() != Method::POST {
-        return Err(RequestMetadataError::InvalidRequest(
-            CodecError::InvalidField {
-                field: "method".into(),
-                reason: "standard WIP routes require POST".into(),
-            },
-        ));
-    }
     let expected = endpoint.route(route);
     if value.uri().path() != expected.path() || value.uri().query().is_some() {
-        return Err(RequestMetadataError::InvalidRequest(
+        return Err(RequestMetadataError::NotFound);
-            CodecError::InvalidField {
+    }
-                field: "route".into(),
+    if value.method() != Method::POST {
-                reason: "request URI does not match the selected standard route".into(),
+        return Err(RequestMetadataError::MethodNotAllowed);
-            },
-        ));
     }
     let valid_content_type = value
         .headers()
         .get(CONTENT_TYPE)
         .and_then(|value| value.to_str().ok())
         .is_some_and(is_json_content_type);
-    if !valid_content_type {
+    if !valid_content_type || !has_supported_content_coding(value.headers()) {
         return Err(RequestMetadataError::UnsupportedMediaType);
     }
     if !accepts_json(value.headers()) {
@@ -526,9 +536,8 @@ fn encode_protocol_error_with_status(
 /// The code must be allowed for `interaction`. This API accepts only
 /// [`ProtocolError`], so client-local `InvalidResponse` and
 /// `UnsupportedDescriptorFormat` classifications cannot be emitted as Host
-/// error envelopes. Resource-limit errors use the logical-limit status; callers
+/// error envelopes. Logical `resource_limit_exceeded` failures use HTTP 422;
-/// that know the concrete limit class should use
+/// representation and deployment limits are not protocol errors.
-/// [`encode_resource_limit_error_response`].
 pub fn encode_protocol_error_response(
     interaction: ProtocolInteraction,
     error: &ProtocolError,
@@ -542,28 +551,6 @@ pub fn encode_protocol_error_response(
     )
 }
 
-/// Encodes a `resource_limit_exceeded` envelope with its class-specific status.
-pub fn encode_resource_limit_error_response(
-    interaction: ProtocolInteraction,
-    error: &ProtocolError,
-    kind: ResourceLimitKind,
-    limits: Limits,
-) -> Result<Response<Vec<u8>>, EncodeHttpError> {
-    if error.code != wip_protocol::ProtocolErrorCode::ResourceLimitExceeded {
-        return Err(CodecError::InvalidField {
-            field: "error.code".into(),
-            reason: "resource-limit encoder requires resource_limit_exceeded".into(),
-        }
-        .into());
-    }
-    encode_protocol_error_with_status(
-        interaction,
-        error,
-        response::status_for_resource_limit(kind),
-        limits,
-    )
-}
-
 /// Failure while building an outbound framework-neutral HTTP message.
 #[derive(Debug)]
 pub enum EncodeHttpError {

crates/wip-http/src/endpoint.rs

@@ -15,8 +15,6 @@ pub enum Route {
     FetchInterface,
     /// Call one operation.
     CallOperation,
-    /// Package independent retrieval interactions.
-    Batch,
 }
 
 impl Route {
@@ -27,7 +25,6 @@ impl Route {
             Self::Observe => "v1/observe",
             Self::FetchInterface => "v1/fetch_interface",
             Self::CallOperation => "v1/call_operation",
-            Self::Batch => "v1/batch",
         }
     }
 }
@@ -82,12 +79,7 @@ impl Endpoint {
     /// are not route components and therefore never match.
     #[must_use]
     pub fn recognize(&self, candidate: &Url) -> Option<Route> {
-        const ROUTES: [Route; 4] = [
+        const ROUTES: [Route; 3] = [Route::Observe, Route::FetchInterface, Route::CallOperation];
-            Route::Observe,
-            Route::FetchInterface,
-            Route::CallOperation,
-            Route::Batch,
-        ];
         if candidate.query().is_some() || candidate.fragment().is_some() {
             return None;
         }

crates/wip-http/src/error.rs

@@ -10,8 +10,6 @@ pub struct Limits {
     pub(crate) max_response_bytes: usize,
     /// Largest accepted JSON container nesting depth.
     pub(crate) max_nesting: usize,
-    /// Largest accepted number of batch items.
-    pub(crate) max_batch_items: usize,
 }
 
 impl Limits {
@@ -20,7 +18,6 @@ impl Limits {
         max_request_bytes: usize,
         max_response_bytes: usize,
         max_nesting: usize,
-        max_batch_items: usize,
     ) -> Result<Self, LimitConfigurationError> {
         if max_request_bytes == 0 {
             return Err(LimitConfigurationError::ZeroRequestBytes);
@@ -31,14 +28,10 @@ impl Limits {
         if max_nesting == 0 {
             return Err(LimitConfigurationError::ZeroNesting);
         }
-        if max_batch_items == 0 {
-            return Err(LimitConfigurationError::ZeroBatchItems);
-        }
         Ok(Self {
             max_request_bytes,
             max_response_bytes,
             max_nesting,
-            max_batch_items,
         })
     }
 
@@ -59,12 +52,6 @@ impl Limits {
     pub const fn max_nesting(self) -> usize {
         self.max_nesting
     }
-
-    /// Returns the batch item count limit.
-    #[must_use]
-    pub const fn max_batch_items(self) -> usize {
-        self.max_batch_items
-    }
 }
 
 /// Why a [`Limits`] configuration is not bounded.
@@ -76,8 +63,6 @@ pub enum LimitConfigurationError {
     ZeroResponseBytes,
     /// Nesting limit was zero.
     ZeroNesting,
-    /// Batch-item limit was zero.
-    ZeroBatchItems,
 }
 
 impl Display for LimitConfigurationError {
@@ -86,7 +71,6 @@ impl Display for LimitConfigurationError {
             Self::ZeroRequestBytes => "request byte limit must be nonzero",
             Self::ZeroResponseBytes => "response byte limit must be nonzero",
             Self::ZeroNesting => "nesting limit must be nonzero",
-            Self::ZeroBatchItems => "batch item limit must be nonzero",
         })
     }
 }
@@ -102,15 +86,6 @@ pub enum BodyKind {
     Response,
 }
 
-/// The class of a resource limit exceeded by a wire representation.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ResourceLimitKind {
-    /// A request or response representation exceeded its byte-size limit.
-    RepresentationBytes,
-    /// A logical limit such as nesting depth, batch count, or collection size was exceeded.
-    Logical,
-}
-
 /// A malformed or locally disallowed wire representation.
 #[derive(Debug)]
 pub enum CodecError {
@@ -157,47 +132,6 @@ pub enum CodecError {
     },
     /// Logical protocol validation rejected the decoded representation.
     ProtocolValidation(wip_protocol::ValidationError),
-    /// The batch exceeds its configured item count.
-    TooManyBatchItems {
-        /// Actual item count.
-        actual: usize,
-        /// Configured maximum.
-        maximum: usize,
-    },
-    /// Batch item identifiers are not unique.
-    DuplicateBatchId {
-        /// Repeated identifier.
-        id: String,
-    },
-    /// A response contains a batch identifier that was not requested.
-    UnexpectedBatchId {
-        /// Unexpected identifier.
-        id: String,
-    },
-    /// A response omitted a requested batch identifier.
-    MissingBatchId {
-        /// Missing identifier.
-        id: String,
-    },
-    /// A batch item result does not match its requested interaction.
-    BatchInteractionMismatch {
-        /// Item identifier.
-        id: String,
-    },
-}
-
-impl CodecError {
-    /// Classifies this failure when it represents a canonical resource limit.
-    #[must_use]
-    pub const fn resource_limit_kind(&self) -> Option<ResourceLimitKind> {
-        match self {
-            Self::BodyTooLarge { .. } => Some(ResourceLimitKind::RepresentationBytes),
-            Self::NestingTooDeep { .. } | Self::TooManyBatchItems { .. } => {
-                Some(ResourceLimitKind::Logical)
-            }
-            _ => None,
-        }
-    }
 }
 
 impl Display for CodecError {
@@ -225,15 +159,6 @@ impl Display for CodecError {
                 write!(formatter, "field `{field}` is not canonical base64")
             }
             Self::ProtocolValidation(error) => error.fmt(formatter),
-            Self::TooManyBatchItems { actual, maximum } => {
-                write!(formatter, "batch has {actual} items; maximum is {maximum}")
-            }
-            Self::DuplicateBatchId { id } => write!(formatter, "duplicate batch id `{id}`"),
-            Self::UnexpectedBatchId { id } => write!(formatter, "unexpected batch id `{id}`"),
-            Self::MissingBatchId { id } => write!(formatter, "missing batch id `{id}`"),
-            Self::BatchInteractionMismatch { id } => {
-                write!(formatter, "batch result does not match request `{id}`")
-            }
         }
     }
 }

crates/wip-http/src/lib.rs

@@ -2,11 +2,11 @@
 //!
 //! This crate owns endpoint and route derivation, UTF-8 JSON encoding, canonical
 //! success and error response handling, HTTP status mapping, descriptor-guided
-//! operation-value conversion, and retrieval batching. It deliberately performs
+//! operation-value conversion. It deliberately performs no I/O and depends on no
-//! no I/O and depends on no server framework, TLS implementation, filesystem
+//! server framework, TLS implementation, filesystem projection, client cache, or
-//! projection, client cache, or presentation layer. URL schemes, TLS,
+//! presentation layer. URL schemes, TLS, certificates, authentication mechanisms,
-//! certificates, authentication mechanisms, proxies, and caches are selected by
+//! proxies, and caches are selected by the HTTP implementation and deployment
-//! the HTTP implementation and deployment rather than by WIP conformance.
+//! rather than by WIP conformance.
 //!
 //! Logical values remain owned by [`wip_protocol`]. Validators and `Bytes` are
 //! encoded in JSON bodies using canonical RFC 4648 Section 4 base64; this crate
@@ -17,7 +17,7 @@
 //! use wip_protocol::ObserveRequest;
 //!
 //! let endpoint = Endpoint::parse("http://example.test/api/wip")?;
-//! let limits = Limits::new(64 * 1024, 1024 * 1024, 64, 100)?;
+//! let limits = Limits::new(64 * 1024, 1024 * 1024, 64)?;
 //! let request = encode_observe_request(
 //!     &endpoint,
 //!     &ObserveRequest { path: "/items/123".into(), depth: 0 },
@@ -30,34 +30,25 @@
 
 #![deny(missing_docs)]
 
-mod batch;
 mod codec;
 mod endpoint;
 mod error;
 mod json;
 mod response;
 
-pub use batch::{
-    BatchMethod, BatchRequest, BatchRequestItem, BatchRequestKind, BatchResponse,
-    BatchResponseItem, BatchSuccess, decode_batch_request, decode_batch_response,
-    encode_batch_error_response, encode_batch_request, encode_batch_resource_limit_error_response,
-    encode_batch_response,
-};
 pub use codec::{
     CallOperationMetadata, EncodeHttpError, RequestMetadataError, decode_call_operation_metadata,
     decode_call_operation_request, decode_call_operation_response, decode_fetch_interface_request,
     decode_fetch_interface_response, decode_observe_request, decode_observe_response,
     encode_call_operation_request, encode_call_operation_response, encode_fetch_interface_request,
     encode_fetch_interface_response, encode_observe_request, encode_observe_response,
-    encode_protocol_error_response, encode_resource_limit_error_response, is_json_content_type,
+    encode_protocol_error_response, is_json_content_type, validate_http_request,
-    validate_http_request,
 };
 pub use endpoint::{Endpoint, EndpointError, JSON_CONTENT_TYPE, Route};
-pub use error::{BodyKind, CodecError, LimitConfigurationError, Limits, ResourceLimitKind};
+pub use error::{BodyKind, CodecError, LimitConfigurationError, Limits};
 pub use response::{
     ClientResponseError, DecodedResponse, InvalidResponseKind, StatusMismatch,
     TransportBindingFailure, TransportFailureKind, error_code_name, status_for_error,
-    status_for_resource_limit,
 };
 
 /// Framework-neutral HTTP types used by this binding's public API.

crates/wip-http/src/response.rs

@@ -5,7 +5,7 @@ use http::StatusCode;
 use serde_json::{Map, Value as Json};
 use wip_protocol::{ProtocolError, ProtocolErrorCode, ProtocolInteraction};
 
-use crate::{BodyKind, CodecError, Limits, ResourceLimitKind, json};
+use crate::{BodyKind, CodecError, Limits, json};
 
 /// A successfully classified client response.
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -37,6 +37,8 @@ pub enum TransportFailureKind {
     AuthenticationRequired,
     /// HTTP 403, commonly emitted by endpoint policy or infrastructure.
     EndpointForbidden,
+    /// The response uses a content coding the client does not support.
+    UnsupportedContentCoding,
     /// Another non-success HTTP response without a WIP error envelope.
     HttpStatus,
 }
@@ -63,8 +65,6 @@ pub enum InvalidResponseKind {
     NonCanonicalSuccessStatus,
     /// A 2xx body was malformed or semantically invalid.
     InvalidSuccessBody,
-    /// A batch response did not correlate exactly with its request.
-    InvalidBatch,
 }
 
 /// A local failure while classifying or validating a peer response.
@@ -119,10 +119,6 @@ impl Display for ClientResponseError {
 impl Error for ClientResponseError {}
 
 /// Returns the canonical HTTP status for a wire-level protocol error.
-///
-/// [`ProtocolErrorCode::ResourceLimitExceeded`] defaults to the logical-limit
-/// status. Use [`status_for_resource_limit`] when the concrete limit class is
-/// known.
 #[must_use]
 pub const fn status_for_error(code: ProtocolErrorCode) -> StatusCode {
     match code {
@@ -145,22 +141,8 @@ pub const fn status_for_error(code: ProtocolErrorCode) -> StatusCode {
     }
 }
 
-/// Returns the canonical HTTP status for a concrete resource-limit class.
-#[must_use]
-pub const fn status_for_resource_limit(kind: ResourceLimitKind) -> StatusCode {
-    match kind {
-        ResourceLimitKind::RepresentationBytes => StatusCode::PAYLOAD_TOO_LARGE,
-        ResourceLimitKind::Logical => StatusCode::UNPROCESSABLE_ENTITY,
-    }
-}
-
 fn status_matches_error(status: StatusCode, code: ProtocolErrorCode) -> bool {
-    match code {
+    status == status_for_error(code)
-        ProtocolErrorCode::ResourceLimitExceeded => {
-            status == StatusCode::PAYLOAD_TOO_LARGE || status == StatusCode::UNPROCESSABLE_ENTITY
-        }
-        _ => status == status_for_error(code),
-    }
 }
 
 /// Returns the stable snake-case wire spelling of a protocol code.
@@ -213,14 +195,7 @@ pub(crate) fn error_to_json(error: &ProtocolError) -> Json {
     })
 }
 
-pub(crate) fn item_error_to_json(error: &ProtocolError) -> Json {
+fn protocol_error_from_json(value: &Json) -> Result<ProtocolError, CodecError> {
-    serde_json::json!({
-        "code": error_code_name(error.code),
-        "message": error.message,
-    })
-}
-
-pub(crate) fn item_error_from_json(value: &Json) -> Result<ProtocolError, CodecError> {
     let fields = value
         .as_object()
         .ok_or_else(|| invalid_field("error", "expected object"))?;
@@ -239,7 +214,7 @@ fn envelope_error_from_json(value: &Json) -> Result<Option<ProtocolError>, Codec
     if fields.len() != 1 || !fields.contains_key("error") {
         return Ok(None);
     }
-    item_error_from_json(&fields["error"]).map(Some)
+    protocol_error_from_json(&fields["error"]).map(Some)
 }
 
 fn exact(fields: &Map<String, Json>, allowed: &[&str], parent: &str) -> Result<(), CodecError> {
@@ -355,6 +330,13 @@ pub(crate) fn decode<T>(
     }
 }
 
+pub(crate) fn unsupported_content_coding(status: StatusCode) -> ClientResponseError {
+    ClientResponseError::TransportBinding(TransportBindingFailure {
+        status,
+        kind: TransportFailureKind::UnsupportedContentCoding,
+    })
+}
+
 pub(crate) fn transport_failure(status: StatusCode) -> ClientResponseError {
     let kind = match status {
         StatusCode::UNAUTHORIZED => TransportFailureKind::AuthenticationRequired,

crates/wip-http/tests/batch.rs

@@ -1,345 +0,0 @@
-use wip_http::http::StatusCode;
-use wip_http::wip_protocol::{
-    FetchInterfaceRequest, FetchInterfaceResponse, INTERFACE_FORMAT_V1, InterfaceDescriptor,
-    Object, ObjectObservation, ObserveRequest, ProtocolError, ProtocolErrorCode,
-};
-use wip_http::{
-    BatchMethod, BatchRequest, BatchRequestItem, BatchRequestKind, BatchResponse,
-    BatchResponseItem, BatchSuccess, ClientResponseError, DecodedResponse, Endpoint,
-    InvalidResponseKind, Limits, ResourceLimitKind, decode_batch_request, decode_batch_response,
-    encode_batch_error_response, encode_batch_request, encode_batch_resource_limit_error_response,
-    encode_batch_response,
-};
-
-fn limits() -> Limits {
-    Limits::new(100_000, 100_000, 64, 4).unwrap()
-}
-
-fn observed_item(validator: Option<Vec<u8>>) -> ObjectObservation {
-    ObjectObservation {
-        object: Object {
-            name: "item".into(),
-            description: None,
-            interfaces: vec![],
-            r#ref: None,
-            validator,
-        },
-        children: None,
-    }
-}
-
-fn request() -> BatchRequest {
-    BatchRequest {
-        requests: vec![
-            BatchRequestItem {
-                id: "object".into(),
-                request: BatchRequestKind::Observe(ObserveRequest {
-                    path: "/item".into(),
-                    depth: 0,
-                }),
-            },
-            BatchRequestItem {
-                id: "interface".into(),
-                request: BatchRequestKind::FetchInterface(FetchInterfaceRequest {
-                    interface: "interface-v1".into(),
-                }),
-            },
-        ],
-    }
-}
-
-#[test]
-fn batch_round_trips_by_unique_id_with_item_failures_and_validators() {
-    let request = request();
-    let endpoint = Endpoint::parse("https://example.test/wip").unwrap();
-    let encoded_request = encode_batch_request(&endpoint, &request, limits()).unwrap();
-    assert_eq!(encoded_request.uri().path(), "/wip/v1/batch");
-    assert_eq!(encoded_request.headers()["accept"], "application/json");
-    assert_eq!(
-        decode_batch_request(encoded_request.body(), limits()).unwrap(),
-        request
-    );
-
-    let response = BatchResponse {
-        responses: vec![
-            BatchResponseItem {
-                id: "interface".into(),
-                outcome: Err(ProtocolError {
-                    code: ProtocolErrorCode::InterfaceNotFound,
-                    message: "gone".into(),
-                }),
-            },
-            BatchResponseItem {
-                id: "object".into(),
-                outcome: Ok(BatchSuccess::Observe(observed_item(Some(vec![
-                    0, 1, 2, 255,
-                ])))),
-            },
-        ],
-    };
-    let encoded = encode_batch_response(&request, &response, limits()).unwrap();
-    assert_eq!(encoded.status(), StatusCode::OK);
-    assert!(
-        std::str::from_utf8(encoded.body())
-            .unwrap()
-            .contains("AAEC/w==")
-    );
-    assert_eq!(
-        decode_batch_response(&request, &encoded, limits()).unwrap(),
-        DecodedResponse::Success(response)
-    );
-}
-
-#[test]
-fn batch_interface_validator_round_trips_in_item_body() {
-    let request = BatchRequest {
-        requests: vec![BatchRequestItem {
-            id: "interface".into(),
-            request: BatchRequestKind::FetchInterface(FetchInterfaceRequest {
-                interface: "interface-v1".into(),
-            }),
-        }],
-    };
-    let response = BatchResponse {
-        responses: vec![BatchResponseItem {
-            id: "interface".into(),
-            outcome: Ok(BatchSuccess::FetchInterface(FetchInterfaceResponse {
-                interface: "interface-v1".into(),
-                descriptor: InterfaceDescriptor {
-                    format: INTERFACE_FORMAT_V1.into(),
-                    documentation: None,
-                    types: vec![],
-                    operations: vec![],
-                },
-                validator: Some(vec![255, 254, 253]),
-            })),
-        }],
-    };
-    let encoded = encode_batch_response(&request, &response, limits()).unwrap();
-    assert!(
-        std::str::from_utf8(encoded.body())
-            .unwrap()
-            .contains("//79")
-    );
-    assert_eq!(
-        decode_batch_response(&request, &encoded, limits()).unwrap(),
-        DecodedResponse::Success(response)
-    );
-}
-
-#[test]
-fn malformed_known_method_arguments_are_item_local() {
-    let body = br#"{
-        "requests": [
-            {"id":"valid","method":"observe","arguments":{"path":"/item","depth":0}},
-            {"id":"invalid","method":"observe","arguments":{"path":"/","depth":"deep"}}
-        ]
-    }"#;
-    let decoded = decode_batch_request(body, limits()).unwrap();
-    assert!(matches!(
-        decoded.requests[0].request,
-        BatchRequestKind::Observe(_)
-    ));
-    let invalid = match &decoded.requests[1].request {
-        BatchRequestKind::Invalid { method, error } => {
-            assert_eq!(*method, BatchMethod::Observe);
-            assert_eq!(error.code, ProtocolErrorCode::InvalidRequest);
-            error.clone()
-        }
-        other => panic!("expected item-local invalid request, got {other:?}"),
-    };
-
-    let response = BatchResponse {
-        responses: vec![
-            BatchResponseItem {
-                id: "valid".into(),
-                outcome: Ok(BatchSuccess::Observe(observed_item(None))),
-            },
-            BatchResponseItem {
-                id: "invalid".into(),
-                outcome: Err(invalid),
-            },
-        ],
-    };
-    let encoded = encode_batch_response(&decoded, &response, limits()).unwrap();
-    assert_eq!(encoded.status(), StatusCode::OK);
-    assert_eq!(
-        decode_batch_response(&decoded, &encoded, limits()).unwrap(),
-        DecodedResponse::Success(response)
-    );
-}
-
-#[test]
-fn invalid_batch_envelopes_are_rejected_at_top_level() {
-    assert!(decode_batch_request(br#"{}"#, limits()).is_err());
-
-    let malformed_item = br#"{
-        "requests": [
-            {"id":"item","method":"observe","arguments":{"path":"/","depth":0},"extra":true}
-        ]
-    }"#;
-    assert!(decode_batch_request(malformed_item, limits()).is_err());
-
-    let duplicate = br#"{
-        "requests": [
-            {"id":"same","method":"observe","arguments":{"path":"/a","depth":0}},
-            {"id":"same","method":"observe","arguments":{"path":"/b","depth":0}}
-        ]
-    }"#;
-    assert!(decode_batch_request(duplicate, limits()).is_err());
-
-    let operation = br#"{
-        "requests": [
-            {"id":"call","method":"call_operation","arguments":{}}
-        ]
-    }"#;
-    assert!(decode_batch_request(operation, limits()).is_err());
-
-    let too_many = Limits::new(100_000, 100_000, 64, 1).unwrap();
-    assert!(decode_batch_request(duplicate, too_many).is_err());
-}
-
-#[test]
-fn batch_resource_limits_use_413_or_422_and_never_429() {
-    let error = ProtocolError {
-        code: ProtocolErrorCode::ResourceLimitExceeded,
-        message: "bounded".into(),
-    };
-    for (kind, status) in [
-        (
-            ResourceLimitKind::RepresentationBytes,
-            StatusCode::PAYLOAD_TOO_LARGE,
-        ),
-        (ResourceLimitKind::Logical, StatusCode::UNPROCESSABLE_ENTITY),
-    ] {
-        let encoded = encode_batch_resource_limit_error_response(&error, kind, limits()).unwrap();
-        assert_eq!(encoded.status(), status);
-        assert_ne!(encoded.status(), StatusCode::TOO_MANY_REQUESTS);
-        assert_eq!(
-            decode_batch_response(&request(), &encoded, limits()).unwrap(),
-            DecodedResponse::ProtocolFailure {
-                error: error.clone(),
-                status_mismatch: None,
-            }
-        );
-    }
-}
-
-#[test]
-fn batch_success_body_requires_exactly_http_200() {
-    let request = request();
-    let response = BatchResponse {
-        responses: vec![
-            BatchResponseItem {
-                id: "object".into(),
-                outcome: Ok(BatchSuccess::Observe(observed_item(None))),
-            },
-            BatchResponseItem {
-                id: "interface".into(),
-                outcome: Err(ProtocolError {
-                    code: ProtocolErrorCode::InterfaceNotFound,
-                    message: "gone".into(),
-                }),
-            },
-        ],
-    };
-    let encoded = encode_batch_response(&request, &response, limits()).unwrap();
-    for status in [StatusCode::CREATED, StatusCode::ACCEPTED] {
-        let mut noncanonical = encoded.clone();
-        *noncanonical.status_mut() = status;
-        assert!(matches!(
-            decode_batch_response(&request, &noncanonical, limits()).unwrap_err(),
-            ClientResponseError::InvalidResponse { .. }
-        ));
-    }
-}
-
-#[test]
-fn top_level_batch_errors_use_the_batch_allowed_code_set() {
-    let invalid = ProtocolError {
-        code: ProtocolErrorCode::InvalidRequest,
-        message: "bad envelope".into(),
-    };
-    let encoded = encode_batch_error_response(&invalid, limits()).unwrap();
-    assert_eq!(
-        decode_batch_response(&request(), &encoded, limits()).unwrap(),
-        DecodedResponse::ProtocolFailure {
-            error: invalid,
-            status_mismatch: None,
-        }
-    );
-
-    let not_found = wip_http::http::Response::builder()
-        .status(StatusCode::NOT_FOUND)
-        .header("content-type", "application/json; charset=utf-8")
-        .body(br#"{"error":{"code":"not_found","message":"not a batch failure"}}"#.to_vec())
-        .unwrap();
-    assert!(matches!(
-        decode_batch_response(&request(), &not_found, limits()).unwrap_err(),
-        ClientResponseError::InvalidResponse {
-            kind: InvalidResponseKind::InvalidBatch,
-            ..
-        }
-    ));
-}
-
-#[test]
-fn unsupported_batch_descriptor_waits_for_envelope_correlation() {
-    let duplicate = wip_http::http::Response::builder()
-        .status(StatusCode::OK)
-        .header("content-type", "application/json; charset=utf-8")
-        .body(
-            br#"{"responses":[{"id":"interface","result":{"interface":"interface-v1","descriptor":{"format":"wip-interface/2","future":true}}},{"id":"interface","result":{"interface":"interface-v1","descriptor":{"format":"wip-interface/2"}}}]}"#
-                .to_vec(),
-        )
-        .unwrap();
-    assert!(matches!(
-        decode_batch_response(&request(), &duplicate, limits()).unwrap_err(),
-        ClientResponseError::InvalidResponse {
-            kind: InvalidResponseKind::InvalidBatch,
-            ..
-        }
-    ));
-
-    let missing = wip_http::http::Response::builder()
-        .status(StatusCode::OK)
-        .header("content-type", "application/json; charset=utf-8")
-        .body(
-            br#"{"responses":[{"id":"interface","result":{"interface":"interface-v1","descriptor":{"format":"wip-interface/2"}}}]}"#
-                .to_vec(),
-        )
-        .unwrap();
-    assert!(matches!(
-        decode_batch_response(&request(), &missing, limits()).unwrap_err(),
-        ClientResponseError::InvalidResponse {
-            kind: InvalidResponseKind::InvalidBatch,
-            ..
-        }
-    ));
-
-    let request = BatchRequest {
-        requests: vec![BatchRequestItem {
-            id: "interface".into(),
-            request: BatchRequestKind::FetchInterface(FetchInterfaceRequest {
-                interface: "interface-v1".into(),
-            }),
-        }],
-    };
-    assert!(matches!(
-        decode_batch_response(&request, &missing, limits()).unwrap_err(),
-        ClientResponseError::UnsupportedDescriptorFormat { format }
-            if format == "wip-interface/2"
-    ));
-}
-
-#[test]
-fn batch_response_must_have_exactly_the_requested_ids() {
-    let request = request();
-    let missing = BatchResponse {
-        responses: vec![BatchResponseItem {
-            id: "object".into(),
-            outcome: Ok(BatchSuccess::Observe(observed_item(None))),
-        }],
-    };
-    assert!(encode_batch_response(&request, &missing, limits()).is_err());
-}

crates/wip-http/tests/codecs.rs

@@ -10,15 +10,15 @@ use wip_http::wip_protocol::{
 };
 use wip_http::{
     ClientResponseError, CodecError, DecodedResponse, Endpoint, InvalidResponseKind, Limits,
-    ResourceLimitKind, decode_call_operation_metadata, decode_call_operation_request,
+    decode_call_operation_metadata, decode_call_operation_request, decode_call_operation_response,
-    decode_call_operation_response, decode_fetch_interface_request,
+    decode_fetch_interface_request, decode_fetch_interface_response, decode_observe_request,
-    decode_fetch_interface_response, decode_observe_request, decode_observe_response,
+    decode_observe_response, encode_call_operation_request, encode_call_operation_response,
-    encode_call_operation_request, encode_call_operation_response, encode_fetch_interface_request,
+    encode_fetch_interface_request, encode_fetch_interface_response, encode_observe_request,
-    encode_fetch_interface_response, encode_observe_request, encode_observe_response,
+    encode_observe_response,
 };
 
 fn limits() -> Limits {
-    Limits::new(1_000_000, 1_000_000, 100, 100).unwrap()
+    Limits::new(1_000_000, 1_000_000, 100).unwrap()
 }
 
 fn endpoint() -> Endpoint {
@@ -404,25 +404,17 @@ fn malformed_unknown_null_and_noncanonical_base64_are_rejected() {
 }
 
 #[test]
-fn caller_limits_bound_bytes_and_nesting() {
+fn caller_limits_remain_local_codec_failures() {
-    let tiny = Limits::new(8, 8, 2, 1).unwrap();
+    let tiny = Limits::new(8, 8, 2).unwrap();
     let too_large = decode_observe_request(br#"{"path":"/long","depth":0}"#, tiny).unwrap_err();
     assert!(matches!(&too_large, CodecError::BodyTooLarge { .. }));
-    assert_eq!(
-        too_large.resource_limit_kind(),
-        Some(ResourceLimitKind::RepresentationBytes)
-    );
 
     let nested = br#"{"path":[[["/"]]],"depth":0}"#;
-    let nesting_limited = Limits::new(1024, 1024, 2, 1).unwrap();
+    let nesting_limited = Limits::new(1024, 1024, 2).unwrap();
     let too_deep = decode_observe_request(nested, nesting_limited).unwrap_err();
     assert!(matches!(&too_deep, CodecError::NestingTooDeep { .. }));
-    assert_eq!(
-        too_deep.resource_limit_kind(),
-        Some(ResourceLimitKind::Logical)
-    );
 
-    let outbound_limited = Limits::new(1_000_000, 1_000_000, 1, 10).unwrap();
+    let outbound_limited = Limits::new(1_000_000, 1_000_000, 1).unwrap();
     assert!(
         encode_call_operation_request(
             &endpoint(),

crates/wip-http/tests/responses.rs

@@ -3,14 +3,13 @@ use wip_http::wip_protocol::{
     ObserveRequest, ProtocolError, ProtocolErrorCode, ProtocolInteraction,
 };
 use wip_http::{
-    ClientResponseError, DecodedResponse, InvalidResponseKind, Limits, ResourceLimitKind,
+    ClientResponseError, DecodedResponse, InvalidResponseKind, Limits, TransportFailureKind,
-    TransportFailureKind, decode_observe_response, encode_protocol_error_response,
+    decode_observe_response, encode_protocol_error_response, error_code_name, is_json_content_type,
-    encode_resource_limit_error_response, error_code_name, is_json_content_type, status_for_error,
+    status_for_error,
-    status_for_resource_limit,
 };
 
 fn limits() -> Limits {
-    Limits::new(64 * 1024, 64 * 1024, 32, 16).unwrap()
+    Limits::new(64 * 1024, 64 * 1024, 32).unwrap()
 }
 
 fn request() -> ObserveRequest {
@@ -120,41 +119,45 @@ fn every_protocol_code_has_stable_name_and_status() {
 }
 
 #[test]
-fn resource_limit_statuses_encode_and_decode_by_concrete_limit_class() {
+fn logical_resource_limit_uses_only_422_and_bare_413_is_transport_failure() {
     let error = ProtocolError {
         code: ProtocolErrorCode::ResourceLimitExceeded,
-        message: "bounded".into(),
+        message: "logical observation limit exceeded".into(),
     };
-    let cases = [
+    let encoded =
-        (
-            ResourceLimitKind::RepresentationBytes,
-            StatusCode::PAYLOAD_TOO_LARGE,
-        ),
-        (ResourceLimitKind::Logical, StatusCode::UNPROCESSABLE_ENTITY),
-    ];
-    for (kind, status) in cases {
-        assert_eq!(status_for_resource_limit(kind), status);
-        let encoded = encode_resource_limit_error_response(
-            ProtocolInteraction::Observe,
-            &error,
-            kind,
-            limits(),
-        )
-        .unwrap();
-        assert_eq!(encoded.status(), status);
-        assert_eq!(
-            decode_observe_response(&request(), &encoded, limits()).unwrap(),
-            DecodedResponse::ProtocolFailure {
-                error: error.clone(),
-                status_mismatch: None,
-            }
-        );
-    }
-
-    let default =
         encode_protocol_error_response(ProtocolInteraction::Observe, &error, limits()).unwrap();
-    assert_eq!(default.status(), StatusCode::UNPROCESSABLE_ENTITY);
+    assert_eq!(encoded.status(), StatusCode::UNPROCESSABLE_ENTITY);
-    assert_ne!(default.status(), StatusCode::TOO_MANY_REQUESTS);
+    assert_eq!(
+        decode_observe_response(&request(), &encoded, limits()).unwrap(),
+        DecodedResponse::ProtocolFailure {
+            error: error.clone(),
+            status_mismatch: None,
+        }
+    );
+
+    let mut noncanonical = encoded;
+    *noncanonical.status_mut() = StatusCode::PAYLOAD_TOO_LARGE;
+    assert_eq!(
+        decode_observe_response(&request(), &noncanonical, limits()).unwrap(),
+        DecodedResponse::ProtocolFailure {
+            error,
+            status_mismatch: Some(wip_http::StatusMismatch {
+                actual: StatusCode::PAYLOAD_TOO_LARGE,
+                expected: StatusCode::UNPROCESSABLE_ENTITY,
+            }),
+        }
+    );
+
+    let bare_413 = Response::builder()
+        .status(StatusCode::PAYLOAD_TOO_LARGE)
+        .body(Vec::<u8>::new())
+        .unwrap();
+    assert!(matches!(
+        decode_observe_response(&request(), &bare_413, limits()).unwrap_err(),
+        ClientResponseError::TransportBinding(failure)
+            if failure.status == StatusCode::PAYLOAD_TOO_LARGE
+                && failure.kind == TransportFailureKind::HttpStatus
+    ));
 }
 
 #[test]
@@ -171,6 +174,49 @@ fn rate_limit_status_without_protocol_envelope_stays_transport_failure() {
     ));
 }
 
+#[test]
+fn unsupported_response_content_coding_is_transport_failure() {
+    let mut encoded = encode_protocol_error_response(
+        ProtocolInteraction::Observe,
+        &ProtocolError {
+            code: ProtocolErrorCode::NotFound,
+            message: "missing".into(),
+        },
+        limits(),
+    )
+    .unwrap();
+    encoded
+        .headers_mut()
+        .insert("content-encoding", "gzip".parse().unwrap());
+    assert!(matches!(
+        decode_observe_response(&request(), &encoded, limits()).unwrap_err(),
+        ClientResponseError::TransportBinding(failure)
+            if failure.status == StatusCode::NOT_FOUND
+                && failure.kind == TransportFailureKind::UnsupportedContentCoding
+    ));
+
+    let success = response(StatusCode::OK, br#"{"object":{"name":"","interfaces":[]}}"#);
+    let mut identity = success.clone();
+    identity
+        .headers_mut()
+        .insert("content-encoding", "identity".parse().unwrap());
+    assert!(matches!(
+        decode_observe_response(&request(), &identity, limits()).unwrap(),
+        DecodedResponse::Success(_)
+    ));
+
+    let mut unsupported = success;
+    unsupported
+        .headers_mut()
+        .insert("content-encoding", "br".parse().unwrap());
+    assert!(matches!(
+        decode_observe_response(&request(), &unsupported, limits()).unwrap_err(),
+        ClientResponseError::TransportBinding(failure)
+            if failure.status == StatusCode::OK
+                && failure.kind == TransportFailureKind::UnsupportedContentCoding
+    ));
+}
+
 #[test]
 fn valid_success_body_requires_exactly_http_200() {
     let success_body = br#"{"object":{"name":"","interfaces":[]}}"#;

crates/wip-http/tests/routes.rs

@@ -14,7 +14,6 @@ fn endpoint_preserves_http_and_https_when_resolving_canonical_routes() {
             (Route::Observe, "v1/observe"),
             (Route::FetchInterface, "v1/fetch_interface"),
             (Route::CallOperation, "v1/call_operation"),
-            (Route::Batch, "v1/batch"),
         ];
         for (route, suffix) in expected {
             let url = format!("{scheme}://example.test/root/prefix/{suffix}");
@@ -61,7 +60,10 @@ fn inbound_http_metadata_enforces_post_route_and_json() {
         .header("content-type", "application/json")
         .body(Vec::<u8>::new())
         .unwrap();
-    assert!(validate_http_request(&endpoint, Route::Observe, &wrong_method).is_err());
+    let error = validate_http_request(&endpoint, Route::Observe, &wrong_method).unwrap_err();
+    assert!(matches!(&error, RequestMetadataError::MethodNotAllowed));
+    assert_eq!(error.status(), StatusCode::METHOD_NOT_ALLOWED);
+    assert_eq!(error.allow(), Some("POST"));
 
     let wrong_route = Request::builder()
         .method(Method::POST)
@@ -69,7 +71,21 @@ fn inbound_http_metadata_enforces_post_route_and_json() {
         .header("content-type", "application/json")
         .body(Vec::<u8>::new())
         .unwrap();
-    assert!(validate_http_request(&endpoint, Route::Observe, &wrong_route).is_err());
+    let error = validate_http_request(&endpoint, Route::Observe, &wrong_route).unwrap_err();
+    assert!(matches!(&error, RequestMetadataError::NotFound));
+    assert_eq!(error.status(), StatusCode::NOT_FOUND);
+    assert_eq!(error.allow(), None);
+
+    let query_and_wrong_method = Request::builder()
+        .method(Method::GET)
+        .uri("/wip/v1/observe?unexpected=true")
+        .header("content-type", "application/json")
+        .body(Vec::<u8>::new())
+        .unwrap();
+    assert!(matches!(
+        validate_http_request(&endpoint, Route::Observe, &query_and_wrong_method).unwrap_err(),
+        RequestMetadataError::NotFound
+    ));
 
     for accept in [
         "text/plain, */*;q=1, application/json;q=0",
@@ -114,6 +130,29 @@ fn inbound_http_metadata_enforces_post_route_and_json() {
         validate_http_request(&endpoint, Route::Observe, &unsupported_media_type).unwrap_err();
     assert!(matches!(&error, RequestMetadataError::UnsupportedMediaType));
     assert_eq!(error.status(), StatusCode::UNSUPPORTED_MEDIA_TYPE);
+
+    for coding in ["gzip", "identity, gzip"] {
+        let unsupported_coding = Request::builder()
+            .method(Method::POST)
+            .uri("/wip/v1/observe")
+            .header("content-type", "application/json")
+            .header("content-encoding", coding)
+            .body(Vec::<u8>::new())
+            .unwrap();
+        let error =
+            validate_http_request(&endpoint, Route::Observe, &unsupported_coding).unwrap_err();
+        assert!(matches!(&error, RequestMetadataError::UnsupportedMediaType));
+        assert_eq!(error.status(), StatusCode::UNSUPPORTED_MEDIA_TYPE);
+    }
+
+    let identity_coding = Request::builder()
+        .method(Method::POST)
+        .uri("/wip/v1/observe")
+        .header("content-type", "application/json")
+        .header("content-encoding", "identity")
+        .body(Vec::<u8>::new())
+        .unwrap();
+    assert!(validate_http_request(&endpoint, Route::Observe, &identity_coding).is_ok());
 }
 
 #[test]
@@ -130,6 +169,7 @@ fn invalid_endpoint_components_and_non_routes_are_rejected() {
     let endpoint = Endpoint::parse("http://example.test/wip").unwrap();
     for outside in [
         "http://example.test/wip/v1/unknown",
+        "http://example.test/wip/v1/batch",
         "http://example.test/wip/v1/observe/extra",
         "https://example.test/wip/v1/observe",
         "http://other.test/wip/v1/observe",

crates/wip-interface-macros/Cargo.toml

@@ -1,9 +1,13 @@
 [package]
 name = "wip-interface-macros"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Procedural macros for WIP interface declarations and DTO codecs"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-interface-macros"
 
 [lib]
 proc-macro = true

crates/wip-interface-macros/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

crates/wip-interface-macros/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-interface-macros/README.md

@@ -0,0 +1,9 @@
+# wip-interface-macros
+
+Procedural-macro implementation used by [`wip-interface`](https://crates.io/crates/wip-interface).
+
+Applications should depend on `wip-interface`, which re-exports `#[interface]` and `#[derive(WipType)]` together with the traits and types required by generated code. Direct use of this implementation crate is not a supported application API.
+
+See the [API documentation](https://docs.rs/wip-interface-macros) for the exported macro entry points.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-interface/Cargo.toml

@@ -1,13 +1,17 @@
 [package]
 name = "wip-interface"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Public Rust authoring API for WIP interfaces and operation value codecs"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-interface"
 
 [dependencies]
-wip-interface-macros = { path = "../wip-interface-macros" }
+wip-interface-macros.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true
 
 [dev-dependencies]
 trybuild = "1"

crates/wip-interface/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

crates/wip-interface/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-interface/README.md

@@ -0,0 +1,32 @@
+# wip-interface
+
+Public Rust authoring API for Web Interface Protocol (WIP) interfaces and application DTO codecs.
+
+The crate re-exports `#[interface]` and `#[derive(WipType)]`, generates Interface Descriptors and typed dispatch companions, and converts application-owned Rust values to and from the transport-independent value model.
+
+```toml
+[dependencies]
+wip-interface = "0.1.0"
+```
+
+```rust
+use wip_interface as wip;
+
+#[derive(wip::WipType)]
+struct Greeting {
+    message: String,
+}
+
+#[wip::interface]
+pub trait Greeter {
+    /// Builds a greeting.
+    ///
+    /// # Returns
+    /// The generated greeting.
+    fn greet(&self, name: String) -> wip::OperationResult<Greeting>;
+}
+```
+
+See the [API documentation](https://docs.rs/wip-interface) for supported interface syntax, DTO shapes, and failure semantics.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-protocol/Cargo.toml

@@ -1,8 +1,12 @@
 [package]
 name = "wip-protocol"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Transport-independent logical model and validation for WIP"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
+readme = "README.md"
+documentation = "https://docs.rs/wip-protocol"
 
 [dependencies]

crates/wip-protocol/LICENSE-APACHE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
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crates/wip-protocol/LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Hare
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

crates/wip-protocol/README.md

@@ -0,0 +1,14 @@
+# wip-protocol
+
+Transport-independent logical types and validation for the Web Interface Protocol (WIP).
+
+This crate defines the canonical Object and Interface Descriptor models, the three Core interaction request and response types, schema-neutral operation `Value`s, validators, protocol errors, and structural validation. It does not define an HTTP mapping, application DTOs, persistence, or network I/O.
+
+```toml
+[dependencies]
+wip-protocol = "0.1.0"
+```
+
+See the [API documentation](https://docs.rs/wip-protocol) for the complete model and validation rules.
+
+Licensed under either of Apache-2.0 or MIT at your option.

crates/wip-public-api-example/Cargo.toml

@@ -1,12 +1,14 @@
 [package]
 name = "wip-public-api-example"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Public-only end-to-end conformance consumer for the WIP Rust APIs"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
 publish = false
 
 [dependencies]
-wip-host = { path = "../wip-host" }
+wip-host.workspace = true
-wip-interface = { path = "../wip-interface" }
+wip-interface.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true

crates/wip-tui/Cargo.toml

@@ -1,9 +1,11 @@
 [package]
 name = "wip-tui"
-version = "0.1.0"
+version.workspace = true
-edition = "2024"
+edition.workspace = true
+rust-version.workspace = true
 description = "Interactive terminal client for exploring and operating WIP Worldspaces"
-license = "MIT OR Apache-2.0"
+license.workspace = true
+repository.workspace = true
 readme = "README.md"
 publish = false
 
@@ -13,10 +15,10 @@ crossterm = "0.28.1"
 ratatui = "0.29.0"
 serde_json = "1"
 ureq = "3.1.2"
-wip-client = { path = "../wip-client" }
+wip-client.workspace = true
-wip-http = { path = "../wip-http" }
+wip-http.workspace = true
-wip-protocol = { path = "../wip-protocol" }
+wip-protocol.workspace = true
 
 [dev-dependencies]
 tempfile = "3"
-wip-fs-server = { path = "../wip-fs-server" }
+wip-fs-server.workspace = true

crates/wip-tui/src/app.rs

@@ -939,7 +939,7 @@ mod tests {
         // A request identity has no public constructor; derive one through the runtime.
         let mut client = wip_client::Client::new(
             wip_client::ClientLimits::new(1, 4, 4, 4, 4).unwrap(),
-            wip_http::Limits::new(1024, 1024, 8, 8).unwrap(),
+            wip_http::Limits::new(1024, 1024, 8).unwrap(),
         );
         let session = client
             .open_session(

crates/wip-tui/src/runtime.rs

@@ -862,8 +862,7 @@ fn collect_entries_at(
 /// Standard bounded wire policy used by the executable and integration tests.
 #[must_use]
 pub fn default_wire_limits() -> Limits {
-    Limits::new(256 * 1024, 2 * 1024 * 1024, 64, 64)
+    Limits::new(256 * 1024, 2 * 1024 * 1024, 64).expect("static runtime wire limits are nonzero")
-        .expect("static runtime wire limits are nonzero")
 }
 
 /// Runs the interactive executable using process configuration.