feat: page console history across compaction

crates/protocol/src/lib.rs

@@ -831,6 +831,34 @@ pub struct SessionSnapshot {
     pub entries: Vec<SessionSnapshotEntry>,
 }
 
+/// One user-visible conversation turn. A turn starts at a canonical user entry
+/// and contains every public committed entry until the next user entry.
+/// `turn_id` is the stable `entry_id` of that first user entry.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+pub struct SessionConversationTurn {
+    pub turn_id: String,
+    pub entries: Vec<SessionSnapshotEntry>,
+}
+
+/// Bounded backward page over the adopted conversation lineage.
+///
+/// Turns remain chronological within a page. `next_cursor` is an opaque,
+/// identity-bound boundary for the page immediately preceding `turns`.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
+#[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
+pub struct SessionHistoryPage {
+    pub session_id: String,
+    /// Stable identity of the adopted active lineage used to fence stale pages.
+    pub lineage_id: String,
+    pub turns: Vec<SessionConversationTurn>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub next_cursor: Option<String>,
+    pub has_more: bool,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
 #[cfg_attr(feature = "json-schema", derive(schemars::JsonSchema))]
@@ -957,8 +985,17 @@ pub enum Event {
     /// activated for a turn. Broadcast to every subscribed client so TUI / GUI
     /// instances show the same user line that reconnect snapshots replay.
     UserMessage {
+        /// Stable durable history identity. Older mixed-version producers omit it.
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        entry_id: Option<String>,
         segments: Vec<Segment>,
     },
+    /// A canonical assistant/tool entry has committed to durable history.
+    /// Streaming events remain the in-flight authority; this event supplies the
+    /// stable identity used to reconcile that live block with paged history.
+    SessionEntryCommitted {
+        entry: SessionSnapshotEntry,
+    },
     /// One agent-injected system item committed to history.
     ///
     /// Carries the JSON form of `session_store::SystemItem`. Covers
@@ -2759,6 +2796,7 @@ mod tests {
     #[test]
     fn event_user_message_roundtrip() {
         let event = Event::UserMessage {
+            entry_id: Some("entry-1".to_string()),
             segments: vec![Segment::text("hello 世界")],
         };
         let json = serde_json::to_string(&event).unwrap();
@@ -2769,7 +2807,7 @@ mod tests {
 
         let decoded: Event = serde_json::from_str(&json).unwrap();
         match decoded {
-            Event::UserMessage { segments } => {
+            Event::UserMessage { segments, .. } => {
                 assert_eq!(segments.len(), 1);
                 match &segments[0] {
                     Segment::Text { content } => assert_eq!(content, "hello 世界"),

crates/protocol/src/typescript.rs

@@ -11,12 +11,13 @@ use crate::{
     InternalWorkerRef, InternalWorkerSnapshot, InvokeKind, MemoryWorkerEvent, Method,
     PasteArtifactAvailability, PasteArtifactMediaType, PasteArtifactRef, PendingSubmissionSummary,
     PendingSubmissionsSnapshot, Permission, RewindSummary, RewindTarget, RewindTargetId, RunResult,
-    ScopeRule, Segment, SessionContentPart, SessionEntryProvenance, SessionMessageRole,
+    ScopeRule, Segment, SessionContentPart, SessionConversationTurn, SessionEntryProvenance,
-    SessionSnapshot, SessionSnapshotEntry, SessionSnapshotEntryData, SessionToolAttachment,
+    SessionHistoryPage, SessionMessageRole, SessionSnapshot, SessionSnapshotEntry,
-    SubmissionDisposition, SymlinkPolicy, ToolResultDisposition, TurnResult,
+    SessionSnapshotEntryData, SessionToolAttachment, SubmissionDisposition, SymlinkPolicy,
-    UploadedFileAvailability, UploadedFileRef, WorkerBusyState, WorkerCommandAcknowledgement,
+    ToolResultDisposition, TurnResult, UploadedFileAvailability, UploadedFileRef, WorkerBusyState,
-    WorkerCommandDisposition, WorkerCommandEnvelope, WorkerCommandKind, WorkerEvent,
+    WorkerCommandAcknowledgement, WorkerCommandDisposition, WorkerCommandEnvelope,
-    WorkerMaintenanceState, WorkerRunState, WorkerState, WorkerStateSnapshot, WorkerStatus,
+    WorkerCommandKind, WorkerEvent, WorkerMaintenanceState, WorkerRunState, WorkerState,
+    WorkerStateSnapshot, WorkerStatus,
     subscription::{
         EventSubscriptionSelector, MAX_CORRELATION_ID_BYTES, MAX_REJECTION_MESSAGE_BYTES,
         MAX_RESOURCE_ID_BYTES, MAX_SUBSCRIPTION_COLLECTION_ITEMS,
@@ -104,6 +105,8 @@ pub fn generated_protocol_types() -> String {
     push_decl::<SessionToolAttachment>(&cfg, &mut output);
     push_decl::<SessionSnapshotEntryData>(&cfg, &mut output);
     push_decl::<SessionSnapshotEntry>(&cfg, &mut output);
+    push_decl::<SessionConversationTurn>(&cfg, &mut output);
+    push_decl::<SessionHistoryPage>(&cfg, &mut output);
     push_decl::<PendingSubmissionSummary>(&cfg, &mut output);
     push_decl::<PendingSubmissionsSnapshot>(&cfg, &mut output);
     push_decl::<SubmissionDisposition>(&cfg, &mut output);

crates/runtime-api/src/lib.rs

@@ -655,6 +655,41 @@ pub struct WorkerSessionRequest {
     pub workspace_id: String,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct WorkerSessionHistoryRequest {
+    pub workspace_id: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub cursor: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub limit: Option<usize>,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum WorkerSessionHistoryUnavailableReason {
+    RetentionMissing,
+    ActivePointerMissing,
+    CorruptLog,
+    MigrationRequired,
+    RetentionExpired,
+    StorageUnavailable,
+    InvalidCursor,
+    ResourceLimit,
+    Unsupported,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[serde(tag = "availability", rename_all = "snake_case")]
+pub enum WorkerSessionHistoryAvailability {
+    Page {
+        page: protocol::SessionHistoryPage,
+    },
+    Unavailable {
+        reason: WorkerSessionHistoryUnavailableReason,
+        message: String,
+    },
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct RetainedSessionIdentity {
     pub session_id: String,
@@ -718,6 +753,17 @@ pub trait RuntimeApi {
         #[query] request: WorkerSessionRequest,
     ) -> Result<WorkerSessionAvailability, RuntimeApiError>;
 
+    #[get(
+        "/v1/workers/{worker_id}/session/history",
+        status = 200,
+        error_status = 400
+    )]
+    async fn worker_session_history(
+        &self,
+        #[path] worker_id: String,
+        #[query] request: WorkerSessionHistoryRequest,
+    ) -> Result<WorkerSessionHistoryAvailability, RuntimeApiError>;
+
     #[post("/v1/workers", status = 200, error_status = 400)]
     async fn create_worker(
         &self,
@@ -1053,6 +1099,17 @@ mod tests {
             Ok(WorkerSessionAvailability::LiveProtocol)
         }
 
+        async fn worker_session_history(
+            &self,
+            _worker_id: String,
+            _request: WorkerSessionHistoryRequest,
+        ) -> Result<WorkerSessionHistoryAvailability, RuntimeApiError> {
+            Ok(WorkerSessionHistoryAvailability::Unavailable {
+                reason: WorkerSessionHistoryUnavailableReason::Unsupported,
+                message: "unsupported".to_string(),
+            })
+        }
+
         async fn create_worker(
             &self,
             _request: CreateWorkerRequest,
@@ -1174,10 +1231,22 @@ mod tests {
         assert_eq!(value["message"], "snapshot exceeds limit");
     }
 
+    #[test]
+    fn worker_session_history_availability_has_closed_tagged_wire_shape() {
+        let value = serde_json::to_value(WorkerSessionHistoryAvailability::Unavailable {
+            reason: WorkerSessionHistoryUnavailableReason::InvalidCursor,
+            message: "cursor is stale".to_string(),
+        })
+        .unwrap();
+        assert_eq!(value["availability"], "unavailable");
+        assert_eq!(value["reason"], "invalid_cursor");
+        assert_eq!(value["message"], "cursor is stale");
+    }
+
     #[test]
     fn contract_inventory_is_complete_and_unique() {
         let operations = RuntimeApiMetadata::OPERATIONS;
-        assert_eq!(operations.len(), 16);
+        assert_eq!(operations.len(), 17);
         let mut routes = operations
             .iter()
             .map(|operation| (format!("{:?}", operation.method), operation.path))

crates/server-api/src/lib.rs

@@ -389,6 +389,20 @@ pub struct WorkspaceWorkerSessionResponse {
     pub observation: runtime_api::WorkerSessionAvailability,
 }
 
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct WorkspaceWorkerSessionHistoryQuery {
+    pub cursor: Option<String>,
+    pub limit: Option<usize>,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct WorkspaceWorkerSessionHistoryResponse {
+    pub subject: WorkspaceWorkerSubject,
+    #[serde(flatten)]
+    pub observation: runtime_api::WorkerSessionHistoryAvailability,
+}
+
 #[api(reqwest, axum, openapi)]
 pub trait ServerApi {
     #[get("/health", status = 200, error_status = 400)]
@@ -1141,6 +1155,20 @@ pub trait ServerApi {
         #[path] worker_id: String,
     ) -> Result<WorkspaceWorkerSessionResponse, ServerApiError>;
 
+    #[get(
+        "/api/w/{workspace_id}/runtimes/{runtime_id}/workers/{worker_id}/session/history",
+        status = 200,
+        error_status = 400,
+        openapi = false
+    )]
+    async fn worker_session_history(
+        &self,
+        #[path] workspace_id: String,
+        #[path] runtime_id: String,
+        #[path] worker_id: String,
+        #[query] query: WorkspaceWorkerSessionHistoryQuery,
+    ) -> Result<WorkspaceWorkerSessionHistoryResponse, ServerApiError>;
+
     #[get(
         "/api/workers",
         status = 200,
@@ -11506,7 +11534,7 @@ mod openapi_artifact_tests {
         ];
         // Session observation retains its existing explicit non-OpenAPI boundary independently of
         // the Runtime/Worker-source signed operation inventory above.
-        const OTHER_OPENAPI_EXCLUDED: &[&str] = &["worker_session"];
+        const OTHER_OPENAPI_EXCLUDED: &[&str] = &["worker_session", "worker_session_history"];
         const DOCUMENTED_SIGNED_INTERNAL: &[&str] = &["workspace_runtime_config"];
         const BROWSER_ONLY: &[&str] = &["merge_request_selector_repair"];
 

crates/session-store/src/lib.rs

@@ -37,23 +37,31 @@ use std::path::Path;
 /// Read an existing retained file without updating its access timestamp.
 /// Observation fails closed when the platform cannot provide that guarantee.
 pub(crate) fn read_without_atime(path: &Path) -> io::Result<Vec<u8>> {
+    read_without_atime_bounded(path, u64::MAX)
+}
+
+/// Read at most `max_bytes + 1` retained bytes without updating access time.
+/// The extra byte lets callers prove that the authoritative file exceeded a
+/// limit without first racing a separate metadata length observation.
+pub(crate) fn read_without_atime_bounded(path: &Path, max_bytes: u64) -> io::Result<Vec<u8>> {
     #[cfg(any(target_os = "linux", target_os = "android"))]
     {
         use std::fs::OpenOptions;
         use std::io::Read;
         use std::os::unix::fs::OpenOptionsExt;
 
-        let mut file = OpenOptions::new()
+        let file = OpenOptions::new()
             .read(true)
             .custom_flags(libc::O_NOATIME)
             .open(path)?;
         let mut bytes = Vec::new();
-        file.read_to_end(&mut bytes)?;
+        file.take(max_bytes.saturating_add(1))
+            .read_to_end(&mut bytes)?;
         Ok(bytes)
     }
     #[cfg(not(any(target_os = "linux", target_os = "android")))]
     {
-        let _ = path;
+        let _ = (path, max_bytes);
         Err(io::Error::new(
             io::ErrorKind::Unsupported,
             "read-only retained observation requires no-atime file reads",
@@ -88,8 +96,12 @@ pub use history::{
 pub use logged_item::{LoggedContentPart, LoggedItem, LoggedRole, from_logged, to_logged};
 pub use paste_artifact::PasteArtifactLimits;
 pub use public_snapshot::{
-    DEFAULT_RETAINED_SNAPSHOT_MAX_BYTES, RetainedSessionIdentity, RetainedSessionSnapshot,
+    DEFAULT_RETAINED_HISTORY_MAX_ENTRIES, DEFAULT_RETAINED_HISTORY_MAX_RESPONSE_BYTES,
-    RetainedSnapshotReadError, project_session_snapshot, read_retained_session_snapshot,
+    DEFAULT_RETAINED_HISTORY_MAX_SCAN_BYTES, DEFAULT_RETAINED_HISTORY_MAX_SEGMENTS,
+    DEFAULT_RETAINED_HISTORY_PAGE_TURNS, DEFAULT_RETAINED_SNAPSHOT_MAX_BYTES,
+    MAX_RETAINED_HISTORY_PAGE_TURNS, RetainedHistoryReadError, RetainedHistoryReadLimits,
+    RetainedSessionIdentity, RetainedSessionSnapshot, RetainedSnapshotReadError,
+    project_session_snapshot, read_retained_session_history_page, read_retained_session_snapshot,
 };
 pub use segment::{
     SegmentStartState, append_entry, append_system_item, classify_logged_history_entry,

crates/session-store/src/store.rs

@@ -33,6 +33,9 @@ pub enum StoreError {
     #[error("log corrupted at line {line}: {message}")]
     Corrupt { line: usize, message: String },
 
+    #[error("retained observation read limit exceeded")]
+    ReadLimitExceeded,
+
     #[error("paste artifact storage is unavailable")]
     PasteArtifactUnsupported,
 

crates/session-store/src/worker_session_store.rs

@@ -111,6 +111,19 @@ impl WorkerSessionStore {
         session_id: SessionId,
         segment_id: SegmentId,
     ) -> Result<Vec<LogEntry>, StoreError> {
+        self.read_all_read_only_bounded(session_id, segment_id, u64::MAX)
+            .map(|(entries, _)| entries)
+    }
+
+    /// Read one retained Segment under an actual byte bound without touching
+    /// access time. The file descriptor read, rather than a preceding stat, is
+    /// the limit authority so concurrent appends cannot evade accounting.
+    pub fn read_all_read_only_bounded(
+        &self,
+        session_id: SessionId,
+        segment_id: SegmentId,
+        max_bytes: u64,
+    ) -> Result<(Vec<LogEntry>, u64), StoreError> {
         let retained_session_id = self.session_id.lock().map_err(|_| StoreError::Corrupt {
             line: 0,
             message: "Worker Session identity lock poisoned".to_string(),
@@ -123,14 +136,18 @@ impl WorkerSessionStore {
             });
         }
         let path = self.log_path(segment_id);
-        let bytes = crate::read_without_atime(&path).map_err(|error| {
+        let bytes = crate::read_without_atime_bounded(&path, max_bytes).map_err(|error| {
             if error.kind() == std::io::ErrorKind::NotFound {
                 StoreError::NotFound(segment_id)
             } else {
                 StoreError::Io(error)
             }
         })?;
-        parse_jsonl(&bytes)
+        let byte_len = bytes.len() as u64;
+        if byte_len > max_bytes {
+            return Err(StoreError::ReadLimitExceeded);
+        }
+        Ok((parse_jsonl(&bytes)?, byte_len))
     }
 
     pub fn segment_log_len(&self, segment_id: SegmentId) -> Result<u64, StoreError> {

crates/standalone/tests/host.rs

@@ -117,7 +117,7 @@ async fn in_process_host_runs_text_and_read_tool_then_shuts_down() {
                 .expect("protocol event")
                 .expect("worker event")
             {
-                Event::UserMessage { segments }
+                Event::UserMessage { segments, .. }
                     if format!("{segments:?}").contains("read the probe") =>
                 {
                     saw_user_message = true;

crates/tui/src/app.rs

@@ -1156,7 +1156,7 @@ impl App {
             Event::PendingSubmissionsChanged { pending } => {
                 self.pending_submissions = pending;
             }
-            Event::UserMessage { segments } => {
+            Event::UserMessage { segments, .. } => {
                 self.turn_index += 1;
                 self.blocks.push(Block::TurnHeader {
                     turn: self.turn_index,
@@ -1176,6 +1176,9 @@ impl App {
                 }
                 self.assistant_streaming = false;
             }
+            // The TUI already renders assistant/tool streaming events. This commit
+            // marker exists so identity-aware clients can reconcile durable history.
+            Event::SessionEntryCommitted { .. } => {}
             Event::SystemItem { item } => {
                 self.apply_system_item(&item);
                 self.assistant_streaming = false;
@@ -3399,6 +3402,7 @@ mod completion_flow_tests {
             ]),
         });
         app.handle_worker_event(Event::UserMessage {
+            entry_id: None,
             segments: vec![Segment::text("first persisted message")],
         });
 
@@ -3417,6 +3421,7 @@ mod completion_flow_tests {
         assert_eq!(input_text(&app), "");
 
         app.handle_worker_event(Event::UserMessage {
+            entry_id: None,
             segments: submitted,
         });
         // Simulate run-derived attachment display after the submitted user line.
@@ -3457,6 +3462,7 @@ mod completion_flow_tests {
         let mut app = App::new("test".into());
         let submitted = submit_text(&mut app, "original submit");
         app.handle_worker_event(Event::UserMessage {
+            entry_id: None,
             segments: submitted,
         });
         for c in "draft while running".chars() {
@@ -3485,6 +3491,7 @@ mod completion_flow_tests {
             let mut app = App::new("test".into());
             let submitted = submit_text(&mut app, "normal run");
             app.handle_worker_event(Event::UserMessage {
+                entry_id: None,
                 segments: submitted,
             });
             app.handle_worker_event(Event::RunEnd { result });

crates/tui/src/console/mod.rs

@@ -1688,6 +1688,7 @@ mod tests {
         );
 
         connection.observe_worker_event(&Event::UserMessage {
+            entry_id: None,
             segments: vec![Segment::text("inspect"), Segment::UploadedFile { file }],
         });
         assert!(connection.pending_attachments.is_empty());
@@ -1776,7 +1777,10 @@ mod tests {
             assert!(!reconcile_attachment_submission(
                 &mut pending,
                 &mut awaiting,
-                &Event::UserMessage { segments },
+                &Event::UserMessage {
+                    entry_id: None,
+                    segments,
+                },
             ));
             assert_eq!(awaiting, expected);
             assert!(pending.is_empty());

crates/worker-runtime/src/execution.rs

@@ -477,6 +477,13 @@ pub struct WorkerSessionObservationRequest {
     pub worker_ref: WorkerRef,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct WorkerSessionHistoryRequest {
+    pub worker_ref: WorkerRef,
+    pub cursor: Option<String>,
+    pub limit: Option<usize>,
+}
+
 pub trait WorkerExecutionBackend: Send + Sync + 'static {
     fn backend_id(&self) -> &str;
 
@@ -497,6 +504,16 @@ pub trait WorkerExecutionBackend: Send + Sync + 'static {
         }
     }
 
+    fn worker_session_history(
+        &self,
+        _request: WorkerSessionHistoryRequest,
+    ) -> runtime_api::WorkerSessionHistoryAvailability {
+        runtime_api::WorkerSessionHistoryAvailability::Unavailable {
+            reason: runtime_api::WorkerSessionHistoryUnavailableReason::Unsupported,
+            message: "session history paging is not supported by this Runtime".to_string(),
+        }
+    }
+
     fn spawn_worker(&self, request: WorkerExecutionSpawnRequest) -> WorkerExecutionSpawnResult;
 
     /// Read-only restore validation performed before any live controller,
@@ -726,6 +743,13 @@ impl WorkerExecutionBackendRef {
         self.backend.worker_session(request)
     }
 
+    pub(crate) fn worker_session_history(
+        &self,
+        request: WorkerSessionHistoryRequest,
+    ) -> runtime_api::WorkerSessionHistoryAvailability {
+        self.backend.worker_session_history(request)
+    }
+
     pub(crate) fn spawn_worker(
         &self,
         request: WorkerExecutionSpawnRequest,

crates/worker-runtime/src/http_server/runtime_management_api.rs

@@ -260,6 +260,35 @@ impl runtime_api::RuntimeApi for RuntimeManagementApi {
             .map_err(api_error)
     }
 
+    async fn worker_session_history(
+        &self,
+        worker_id: String,
+        request: runtime_api::WorkerSessionHistoryRequest,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, runtime_api::RuntimeApiError> {
+        let worker_ref = worker_ref_for(&self.state.runtime, worker_id).map_err(api_error)?;
+        let scope = auth_workspace_scope(&self.state, auth_extension().as_ref())
+            .map_err(api_error)?
+            .ok_or_else(|| {
+                runtime_api::RuntimeApiError::new(
+                    StatusCode::FORBIDDEN.as_u16(),
+                    "runtime_worker_session_scope_required",
+                    "Worker Session history requires a Workspace-scoped capability",
+                )
+            })?;
+        if scope.workspace_id != request.workspace_id {
+            return Err(runtime_api::RuntimeApiError::new(
+                StatusCode::FORBIDDEN.as_u16(),
+                "runtime_worker_session_workspace_scope_mismatch",
+                "Worker Session Workspace scope does not match the authenticated capability",
+            ));
+        }
+        self.state
+            .runtime
+            .worker_session_history_scoped(&scope, &worker_ref, request.cursor, request.limit)
+            .map_err(RuntimeHttpRestError::runtime)
+            .map_err(api_error)
+    }
+
     async fn create_worker(
         &self,
         value: runtime_api::CreateWorkerRequest,

crates/worker-runtime/src/runtime.rs

@@ -16,7 +16,8 @@ use crate::execution::{
     WorkerExecutionBackend, WorkerExecutionBackendRef, WorkerExecutionHandle,
     WorkerExecutionOperation, WorkerExecutionResult, WorkerExecutionSpawnRequest,
     WorkerExecutionSpawnResult, WorkerExecutionStopRequest, WorkerLifecycleOperationId,
-    WorkerSessionObservationRequest, WorkspaceConfigFetchRequest, WorkspaceConfigFetchResult,
+    WorkerSessionHistoryRequest, WorkerSessionObservationRequest, WorkspaceConfigFetchRequest,
+    WorkspaceConfigFetchResult,
 };
 #[cfg(feature = "fs-store")]
 use crate::fs_store::{
@@ -1613,6 +1614,38 @@ impl Runtime {
         })
     }
 
+    /// Read one bounded page from the adopted durable Session lineage without
+    /// restoring the Worker or modifying model context.
+    pub fn worker_session_history_scoped(
+        &self,
+        scope: &RuntimeWorkspaceScope,
+        worker_ref: &WorkerRef,
+        cursor: Option<String>,
+        limit: Option<usize>,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, RuntimeError> {
+        let operation_lock = self.worker_operation_lock(worker_ref.worker_id)?;
+        let _operation_guard = operation_lock
+            .lock()
+            .map_err(|_| RuntimeError::StatePoisoned)?;
+        self.ensure_worker_in_workspace(scope, worker_ref)?;
+        let backend = {
+            let state = self.lock()?;
+            state.worker(worker_ref)?;
+            state.execution_backend.clone()
+        };
+        Ok(match backend {
+            Some(backend) => backend.worker_session_history(WorkerSessionHistoryRequest {
+                worker_ref: worker_ref.clone(),
+                cursor,
+                limit,
+            }),
+            None => runtime_api::WorkerSessionHistoryAvailability::Unavailable {
+                reason: runtime_api::WorkerSessionHistoryUnavailableReason::Unsupported,
+                message: "session history paging is not supported by this Runtime".to_string(),
+            },
+        })
+    }
+
     /// Attach a live execution through a workspace-scoped Runtime authorization context.
     pub fn restore_worker_scoped(
         &self,

crates/worker-runtime/src/worker_backend.rs

@@ -172,6 +172,15 @@ pub trait RuntimeWorkerFactory: Send + Sync + 'static {
         Err(session_store::RetainedSnapshotReadError::RetentionMissing)
     }
 
+    fn retained_session_history_page(
+        &self,
+        _worker_ref: &WorkerRef,
+        _cursor: Option<&str>,
+        _limit: Option<usize>,
+    ) -> Result<protocol::SessionHistoryPage, session_store::RetainedHistoryReadError> {
+        Err(session_store::RetainedHistoryReadError::RetentionMissing)
+    }
+
     async fn spawn_controller(
         &self,
         request: WorkerExecutionSpawnRequest,
@@ -1027,6 +1036,25 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
         )
     }
 
+    fn retained_session_history_page(
+        &self,
+        worker_ref: &WorkerRef,
+        cursor: Option<&str>,
+        limit: Option<usize>,
+    ) -> Result<protocol::SessionHistoryPage, session_store::RetainedHistoryReadError> {
+        let aggregate_dir = self
+            .worker_aggregate_dir(worker_ref)
+            .map_err(|_| session_store::RetainedHistoryReadError::RetentionMissing)?;
+        let worker_name = Self::runtime_worker_name_for_ref(worker_ref);
+        session_store::read_retained_session_history_page(
+            &aggregate_dir,
+            &worker_name,
+            cursor,
+            limit,
+            session_store::RetainedHistoryReadLimits::default(),
+        )
+    }
+
     fn observe_workspace_prompt_projection(
         &self,
         projection: worker::WorkspacePromptProjection,
@@ -2216,6 +2244,48 @@ where
         }
     }
 
+    fn worker_session_history(
+        &self,
+        request: crate::execution::WorkerSessionHistoryRequest,
+    ) -> runtime_api::WorkerSessionHistoryAvailability {
+        match self.factory.retained_session_history_page(
+            &request.worker_ref,
+            request.cursor.as_deref(),
+            request.limit,
+        ) {
+            Ok(page) => runtime_api::WorkerSessionHistoryAvailability::Page { page },
+            Err(error) => {
+                let reason = match error {
+                    session_store::RetainedHistoryReadError::RetentionMissing => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::RetentionMissing
+                    }
+                    session_store::RetainedHistoryReadError::ActivePointerMissing => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::ActivePointerMissing
+                    }
+                    session_store::RetainedHistoryReadError::MigrationRequired => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::MigrationRequired
+                    }
+                    session_store::RetainedHistoryReadError::CorruptLog => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::CorruptLog
+                    }
+                    session_store::RetainedHistoryReadError::StorageUnavailable => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::StorageUnavailable
+                    }
+                    session_store::RetainedHistoryReadError::InvalidCursor => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::InvalidCursor
+                    }
+                    session_store::RetainedHistoryReadError::ResourceLimit => {
+                        runtime_api::WorkerSessionHistoryUnavailableReason::ResourceLimit
+                    }
+                };
+                runtime_api::WorkerSessionHistoryAvailability::Unavailable {
+                    reason,
+                    message: error.to_string(),
+                }
+            }
+        }
+    }
+
     fn observe_workspace_prompt_projection(
         &self,
         projection: worker::WorkspacePromptProjection,

crates/worker/src/in_flight.rs

@@ -619,8 +619,8 @@ mod tests {
         let (committed_tx, committed_rx) = mpsc::channel();
         let commit_thread = thread::spawn(move || {
             // This mirrors Worker::append_entry ordering: clear in-flight first,
-            // then publish the finalized AssistantItem. AssistantItem entries
+            // then publish the finalized AssistantItem. Identity-aware clients
-            // are mirror-only and are not delivered as live entry events.
+            // reconcile this durable commit with the preceding streamed block.
             in_flight_for_commit.clear_for_committed_item_then(&assistant_item, || {
                 sink_for_commit.publish(assistant_entry);
             });
@@ -639,7 +639,10 @@ mod tests {
             in_flight_snapshot.blocks.as_slice(),
             [InFlightBlock::Text { text, finished: true }] if text == "done"
         ));
-        assert!(entry_rx.try_recv().is_err());
+        assert!(matches!(
+            entry_rx.try_recv(),
+            Ok(LogEntry::AnnotatedAssistantItem { .. })
+        ));
         let post_commit_guard = in_flight.snapshot_guard();
         assert!(snapshot_from_guard(&post_commit_guard).is_empty());
     }

crates/worker/src/ipc/protocol_session.rs

@@ -34,7 +34,41 @@ pub fn live_log_entry_event(entry: LogEntry) -> Option<Event> {
                 session_store::public_snapshot::project_current_session_snapshot(&[entry]);
             Some(Event::SegmentRotated { session })
         }
-        LogEntry::AnnotatedUserInput { segments, .. } => Some(Event::UserMessage { segments }),
+        LogEntry::AnnotatedUserInput {
+            ts,
+            segments,
+            history,
+            extensions,
+        } => {
+            let projected = session_store::public_snapshot::project_current_session_snapshot(&[
+                LogEntry::AnnotatedUserInput {
+                    ts,
+                    segments: segments.clone(),
+                    history,
+                    extensions,
+                },
+            ]);
+            let entry_id = projected
+                .entries
+                .iter()
+                .find(|entry| {
+                    matches!(
+                        entry.data,
+                        protocol::SessionSnapshotEntryData::UserInput { .. }
+                    )
+                })
+                .map(|entry| entry.entry_id.clone());
+            Some(Event::UserMessage { entry_id, segments })
+        }
+        entry
+        @ (LogEntry::AnnotatedAssistantItem { .. } | LogEntry::AnnotatedToolResult { .. }) => {
+            let mut projected =
+                session_store::public_snapshot::project_current_session_snapshot(&[entry]);
+            projected
+                .entries
+                .pop()
+                .map(|entry| Event::SessionEntryCommitted { entry })
+        }
         LogEntry::AnnotatedSystemItem { entry, .. } => {
             let value = serde_json::to_value(&entry.item).expect("SystemItem is Serialize");
             Some(Event::SystemItem { item: value })
@@ -94,7 +128,9 @@ mod tests {
         .expect("UserInput must be live-relevant");
 
         match event {
-            Event::UserMessage { segments: echoed } => assert_eq!(echoed, segments),
+            Event::UserMessage {
+                segments: echoed, ..
+            } => assert_eq!(echoed, segments),
             other => panic!("expected UserMessage, got {other:?}"),
         }
     }

crates/worker/src/segment_log_sink.rs

@@ -92,14 +92,11 @@ impl SegmentLogSink {
     ///   - `LogEntry::AnnotatedSegmentStart` → `Event::SegmentRotated` on the wire.
     ///   - `LogEntry::AnnotatedUserInput`    → `Event::UserMessage`.
     ///   - `LogEntry::AnnotatedSystemItem`   → `Event::SystemItem`.
+    ///   - assistant/tool commits            → `Event::SessionEntryCommitted`.
     ///   - `LogEntry::Invoke`       → `Event::InvokeStart`.
-    /// Everything else (AssistantItem, ToolResult, TurnEnd,
+    /// Operational checkpoints remain mirror-only. Assistant/tool streaming
-    /// RunCompleted, RunErrored, PausedTurnAbandoned, LlmUsage, Extension,
+    /// events are still the in-flight authority; the committed-entry event adds
-    /// ConfigChanged) is reflected in the mirror so reconnect snapshots stay accurate,
+    /// the durable stable identity needed to reconcile retained history.
-    /// but is not sent live — the streaming events (TextDelta /
-    /// ToolCallStart / ToolResult / TurnEnd / etc.) already provide
-    /// that data, and re-broadcasting it as a typed entry would just
-    /// double-render every block on the client side.
     pub fn publish(&self, entry: LogEntry) {
         let mut mirror = self
             .inner
@@ -122,6 +119,8 @@ impl SegmentLogSink {
             entry,
             LogEntry::AnnotatedSegmentStart { .. }
                 | LogEntry::AnnotatedUserInput { .. }
+                | LogEntry::AnnotatedAssistantItem { .. }
+                | LogEntry::AnnotatedToolResult { .. }
                 | LogEntry::AnnotatedSystemItem { .. }
                 | LogEntry::Invoke { .. }
         )

crates/workspace-server/src/hosts.rs

@@ -1188,6 +1188,19 @@ pub trait WorkspaceWorkerRuntime: Send + Sync {
         })
     }
 
+    fn worker_session_history(
+        &self,
+        _workspace_id: &str,
+        _worker_ref: &EmbeddedWorkerRef,
+        _cursor: Option<String>,
+        _limit: Option<usize>,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, String> {
+        Ok(runtime_api::WorkerSessionHistoryAvailability::Unavailable {
+            reason: runtime_api::WorkerSessionHistoryUnavailableReason::Unsupported,
+            message: "session history paging is not supported by this Runtime".to_string(),
+        })
+    }
+
     fn observation_source(
         &self,
         _worker_id: &str,
@@ -2017,6 +2030,31 @@ impl RuntimeRegistry {
             })
     }
 
+    pub fn worker_session_history(
+        &self,
+        workspace_id: &str,
+        worker: &RuntimeWorkerRef,
+        cursor: Option<String>,
+        limit: Option<usize>,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, RuntimeRegistryError> {
+        validate_backend_identifier("runtime_id", &worker.runtime_id)?;
+        validate_backend_identifier("worker_id", &worker.worker_id)?;
+        let runtime = self.runtime(&worker.runtime_id)?;
+        let worker_ref =
+            EmbeddedWorkerRef::new(EmbeddedWorkerId::parse(&worker.worker_id).ok_or_else(
+                || RuntimeRegistryError::UnknownWorker {
+                    worker: worker.clone(),
+                },
+            )?);
+        runtime
+            .worker_session_history(workspace_id, &worker_ref, cursor, limit)
+            .map_err(|message| RuntimeRegistryError::RuntimeOperationFailed {
+                runtime_id: worker.runtime_id.clone(),
+                code: "worker_session_history_failed".to_string(),
+                message,
+            })
+    }
+
     pub fn observation_source(
         &self,
         worker: &RuntimeWorkerRef,
@@ -2909,6 +2947,19 @@ impl WorkspaceWorkerRuntime for EmbeddedWorkerRuntime {
             .map_err(|error| error.to_string())
     }
 
+    fn worker_session_history(
+        &self,
+        workspace_id: &str,
+        worker_ref: &EmbeddedWorkerRef,
+        cursor: Option<String>,
+        limit: Option<usize>,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, String> {
+        let scope = RuntimeWorkspaceScope::new(workspace_id, "embedded-backend");
+        self.runtime
+            .worker_session_history_scoped(&scope, worker_ref, cursor, limit)
+            .map_err(|error| error.to_string())
+    }
+
     fn observation_source(
         &self,
         worker_id: &str,
@@ -4924,6 +4975,27 @@ impl WorkspaceWorkerRuntime for RemoteWorkerRuntime {
         .map_err(|diagnostic| diagnostic.message)
     }
 
+    fn worker_session_history(
+        &self,
+        workspace_id: &str,
+        worker_ref: &EmbeddedWorkerRef,
+        cursor: Option<String>,
+        limit: Option<usize>,
+    ) -> Result<runtime_api::WorkerSessionHistoryAvailability, String> {
+        let worker_id = worker_ref.worker_id.to_string();
+        let request = runtime_api::WorkerSessionHistoryRequest {
+            workspace_id: workspace_id.to_string(),
+            cursor,
+            limit,
+        };
+        self.run_runtime_api(
+            self.request_timeout,
+            MAX_REMOTE_RUNTIME_RESPONSE_BYTES,
+            move |client| async move { client.worker_session_history(worker_id, request).await },
+        )
+        .map_err(|diagnostic| diagnostic.message)
+    }
+
     fn observation_source(
         &self,
         worker_id: &str,

crates/workspace-server/src/server.rs

@@ -4584,6 +4584,9 @@ fn generated_workspace_contract_router(service: ServerApiContractService) -> Rou
         .merge(server_api::server_api_axum::skill_get(service.clone()))
         .merge(server_api::server_api_axum::skill_activate(service.clone()))
         .merge(server_api::server_api_axum::worker_session(service.clone()))
+        .merge(server_api::server_api_axum::worker_session_history(
+            service.clone(),
+        ))
         .merge(server_api::server_api_axum::repository_list(
             service.clone(),
         ))
@@ -6248,6 +6251,50 @@ impl server_api::ServerApi for ServerApiContractService {
         })
     }
 
+    async fn worker_session_history(
+        &self,
+        workspace_id: String,
+        runtime_id: String,
+        worker_id: String,
+        query: server_api::WorkspaceWorkerSessionHistoryQuery,
+    ) -> std::result::Result<
+        server_api::WorkspaceWorkerSessionHistoryResponse,
+        server_api::ServerApiError,
+    > {
+        let api = self.workspace_api().map_err(|_| {
+            runtime_api::RuntimeApiError::new(
+                StatusCode::NOT_FOUND.as_u16(),
+                "workspace_not_found",
+                "Workspace was not found",
+            )
+        })?;
+        if workspace_id != api.config.workspace_id {
+            return Err(runtime_api::RuntimeApiError::new(
+                StatusCode::NOT_FOUND.as_u16(),
+                "workspace_not_found",
+                "Workspace was not found",
+            ));
+        }
+        let worker = RuntimeWorkerRef::new(runtime_id.clone(), worker_id.clone());
+        let observation = api
+            .runtime
+            .worker_session_history(&workspace_id, &worker, query.cursor, query.limit)
+            .map_err(|_error| {
+                runtime_api::RuntimeApiError::new(
+                    StatusCode::BAD_GATEWAY.as_u16(),
+                    "worker_session_history_failed",
+                    "Worker Session history request failed",
+                )
+            })?;
+        Ok(server_api::WorkspaceWorkerSessionHistoryResponse {
+            subject: server_api::WorkspaceWorkerSubject::RuntimeWorker {
+                runtime_id,
+                worker_id,
+            },
+            observation,
+        })
+    }
+
     async fn workspace_worker_list_alias(
         &self,
     ) -> std::result::Result<server_api::WorkerListResponse, server_api::RepositoryApiError> {

openapi/server-api.json

@@ -14020,7 +14020,7 @@
   "info": {
     "title": "Yoi Server API",
     "version": "0.1.0",
-    "x-yoi-source-digest": "sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052"
+    "x-yoi-source-digest": "sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0"
   },
   "openapi": "3.1.0",
   "paths": {

web/workspace/deno.json

@@ -6,7 +6,7 @@
     "dev": "deno run -A npm:vite@7.2.7 dev",
     "dev:backend": "cd ../.. && cargo run -p yoi-workspace-server --bin yoi-server -- serve --listen 127.0.0.1:8787",
     "check": "deno run -A npm:@sveltejs/kit@2.49.4 sync && deno run -A npm:svelte-check@4.3.4 --tsconfig ./tsconfig.json",
-    "test": "deno test --allow-read=src,test,tests,../../docs --allow-env=LOG,VSCODE_TEXTMATE_DEBUG,NODE_ENV tests/workspace-model.test.ts tests/repository-api.test.ts tests/workspace-catalog.test.ts tests/profile-api.test.ts tests/skill-api.test.ts tests/tooltip-contract.test.ts tests/bevel-contract.test.ts tests/bevel-line-contract.test.ts tests/typography-contract.test.ts src/lib/workspace/auth/model.test.ts src/lib/workspace/protocol-validator.test.ts tests/auth-api.test.ts src/lib/workspace/api/http.test.ts src/lib/workspace/api/workers.test.ts src/lib/workspace/api/ticket-browser.test.ts src/lib/workspace/header/breadcrumb-model.test.ts src/lib/workspace/console/chat-submit.test.ts src/lib/workspace/console/composer-delivery.test.ts test/composer-history.test.ts tests/composer-paste.test.ts src/lib/workspace/console/composer-command.test.ts src/lib/workspace/console/composer-draft.test.ts src/lib/workspace/console/composer-completion.test.ts test/console/ansi.test.ts src/lib/workspace/console/model.test.ts src/lib/workspace/console/run-status.test.ts src/lib/workspace/companion/api.test.ts tests/workdir-api.test.ts tests/workdir-permissions.test.ts src/lib/workspace/console/tasks.test.ts test/ticket-detail-route-reuse.test.ts test/spa-shell.test.ts test/objective-pages.test.ts test/repositories/ui.test.ts src/lib/workspace/console/worker-console.ui.test.ts src/lib/workspace/settings/model.test.ts tests/runtime-connection.test.ts tests/runtime-management.test.ts tests/runtime-management-source.test.ts src/lib/workspace/sidebar/override-stack.test.ts src/lib/workspace/sidebar/route-ownership.test.ts src/lib/workspace/sidebar/workers.test.ts src/lib/workspace/sidebar/workspace-switcher.test.ts src/lib/workspace/sidebar/worker-subscription.test.ts src/lib/workspace/sidebar/worker-workdir-meta.test.ts src/lib/workspace/sidebar/worker-launch.test.ts test/sidebar/worker-actions.test.ts src/lib/workspace/tickets/merge-request-resources.test.ts src/lib/workspace/tickets/ticket-panel.test.ts test/merge-request-status.test.ts test/config-source/decodal-grammar.test.ts test/config-source/editor-state.test.ts test/config-source/fixed-schema-wrapper.test.ts test/config-source/toolchain.test.ts test/config-source/wasm-parity.test.ts test/config-source/api.test.ts tests/memory-api.test.ts test/repository-access/api.test.ts test/repository-access/loader.test.ts test/repository-access/model.test.ts test/repository-access/structure.test.ts test/repository-ssh-connection-ui.test.ts",
+    "test": "deno test --allow-read=src,test,tests,../../docs --allow-env=LOG,VSCODE_TEXTMATE_DEBUG,NODE_ENV tests/workspace-model.test.ts tests/repository-api.test.ts tests/workspace-catalog.test.ts tests/profile-api.test.ts tests/skill-api.test.ts tests/tooltip-contract.test.ts tests/bevel-contract.test.ts tests/bevel-line-contract.test.ts tests/typography-contract.test.ts src/lib/workspace/auth/model.test.ts src/lib/workspace/protocol-validator.test.ts tests/auth-api.test.ts src/lib/workspace/api/http.test.ts src/lib/workspace/api/workers.test.ts src/lib/workspace/api/ticket-browser.test.ts src/lib/workspace/header/breadcrumb-model.test.ts src/lib/workspace/console/chat-submit.test.ts src/lib/workspace/console/composer-delivery.test.ts test/composer-history.test.ts tests/composer-paste.test.ts src/lib/workspace/console/composer-command.test.ts src/lib/workspace/console/composer-draft.test.ts src/lib/workspace/console/composer-completion.test.ts test/console/ansi.test.ts src/lib/workspace/console/history.test.ts src/lib/workspace/console/model.test.ts src/lib/workspace/console/run-status.test.ts src/lib/workspace/companion/api.test.ts tests/workdir-api.test.ts tests/workdir-permissions.test.ts src/lib/workspace/console/tasks.test.ts test/ticket-detail-route-reuse.test.ts test/spa-shell.test.ts test/objective-pages.test.ts test/repositories/ui.test.ts src/lib/workspace/console/worker-console.ui.test.ts src/lib/workspace/settings/model.test.ts tests/runtime-connection.test.ts tests/runtime-management.test.ts tests/runtime-management-source.test.ts src/lib/workspace/sidebar/override-stack.test.ts src/lib/workspace/sidebar/route-ownership.test.ts src/lib/workspace/sidebar/workers.test.ts src/lib/workspace/sidebar/workspace-switcher.test.ts src/lib/workspace/sidebar/worker-subscription.test.ts src/lib/workspace/sidebar/worker-workdir-meta.test.ts src/lib/workspace/sidebar/worker-launch.test.ts test/sidebar/worker-actions.test.ts src/lib/workspace/tickets/merge-request-resources.test.ts src/lib/workspace/tickets/ticket-panel.test.ts test/merge-request-status.test.ts test/config-source/decodal-grammar.test.ts test/config-source/editor-state.test.ts test/config-source/fixed-schema-wrapper.test.ts test/config-source/toolchain.test.ts test/config-source/wasm-parity.test.ts test/config-source/api.test.ts tests/memory-api.test.ts test/repository-access/api.test.ts test/repository-access/loader.test.ts test/repository-access/model.test.ts test/repository-access/structure.test.ts test/repository-ssh-connection-ui.test.ts",
     "test:component": "deno run -A npm:vitest@3.2.4 run --config vitest.config.ts",
     "build": "deno run -A npm:vite@7.2.7 build",
     "preview": "deno run -A npm:vite@7.2.7 preview",

web/workspace/src/lib/generated/companion-api.ts

@@ -1,6 +1,6 @@
 // @generated by yoi-companion-openapi-typescript@1. Do not edit.
 // Input: openapi/server-api.json
-// Input contract: 0.1.0 (sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052)
+// Input contract: 0.1.0 (sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0)
 // Options: companion-operation-schema-closure,openapi-3.1,strict-integer-ranges,sorted-output
 // Output: web/workspace/src/lib/generated/companion-api.ts
 // Regenerate/check: cargo run -q -p server-api --example generate_companion_api_types -- --check

web/workspace/src/lib/generated/protocol.ts

@@ -149,6 +149,14 @@ entry_id: string,
  */
 timestamp: number, provenance: SessionEntryProvenance, derived_from?: Array<string>, } & ({ "kind": "user_input", segments: Array<Segment>, } | { "kind": "message", role: SessionMessageRole, content: Array<SessionContentPart>, } | { "kind": "tool_call", call_id: string, name: string, arguments: string, } | { "kind": "tool_result", call_id: string, summary: string, content?: string | null, is_error: boolean, attachments?: Array<SessionToolAttachment>, } | { "kind": "system_item", item_kind: string, content: string, data?: unknown, } | { "kind": "run_error", message: string, });
 
+export type SessionConversationTurn = { turn_id: string, entries: Array<SessionSnapshotEntry>, };
+
+export type SessionHistoryPage = { session_id: string,
+/**
+ * Stable identity of the adopted active lineage used to fence stale pages.
+ */
+lineage_id: string, turns: Array<SessionConversationTurn>, next_cursor?: string | null, has_more: boolean, };
+
 export type PendingSubmissionSummary = { submission_id: string, accepted_at_ms: number, segment_count: number, byte_len: number, };
 
 export type PendingSubmissionsSnapshot = { revision: number, notification_count: number, head_id: string | null, submissions: Array<PendingSubmissionSummary>, };
@@ -296,7 +304,11 @@ export type SubscriptionFrame = { protocol_version: number, } & ({ "frame": "req
 
 export type Method = { "method": "submit", "params": { submission_request_id: string, input: Array<Segment>, } } | { "method": "notify", "params": { notification_request_id: string, message: string, } } | { "method": "worker_event", "params": WorkerEvent } | { "method": "list_pending_submissions" } | { "method": "cancel_pending_submission", "params": { submission_id: string, expected_revision: number, } } | { "method": "clear_pending_submissions", "params": { expected_revision: number, } } | { "method": "continue_pending", "params": { expected_revision: number, expected_head_id: string, } } | { "method": "resume", "params": { command: WorkerCommandEnvelope, } } | { "method": "cancel", "params": { command: WorkerCommandEnvelope, } } | { "method": "pause", "params": { command: WorkerCommandEnvelope, } } | { "method": "compact", "params": { command: WorkerCommandEnvelope, } } | { "method": "list_rewind_targets" } | { "method": "rewind_to", "params": { target: RewindTargetId, expected_head_entries: number, } } | { "method": "shutdown", "params": { command: WorkerCommandEnvelope, } } | { "method": "list_completions", "params": { kind: CompletionKind, prefix: string, } } | { "method": "list_workers" } | { "method": "restore_worker", "params": { name: string, } } | { "method": "register_peer", "params": { name: string, } };
 
-export type Event = { "event": "submission_accepted", "data": { submission_request_id: string, submission_id: string, disposition: SubmissionDisposition, } } | { "event": "submission_rejected", "data": { submission_request_id: string, message: string, } } | { "event": "pending_submissions_changed", "data": { pending: PendingSubmissionsSnapshot, } } | { "event": "user_message", "data": { segments: Array<Segment>, } } | { "event": "system_item", "data": { item: unknown, } } | { "event": "invoke_start", "data": { kind: InvokeKind, } } | { "event": "turn_start", "data": { turn: number, } } | { "event": "turn_end", "data": { turn: number, result: TurnResult, } } | { "event": "llm_call_start", "data": { llm_call: number, } } | { "event": "llm_call_end", "data": { llm_call: number, } } | { "event": "llm_retry", "data": { llm_call: number,
+export type Event = { "event": "submission_accepted", "data": { submission_request_id: string, submission_id: string, disposition: SubmissionDisposition, } } | { "event": "submission_rejected", "data": { submission_request_id: string, message: string, } } | { "event": "pending_submissions_changed", "data": { pending: PendingSubmissionsSnapshot, } } | { "event": "user_message", "data": {
+/**
+ * Stable durable history identity. Older mixed-version producers omit it.
+ */
+entry_id?: string | null, segments: Array<Segment>, } } | { "event": "session_entry_committed", "data": { entry: SessionSnapshotEntry, } } | { "event": "system_item", "data": { item: unknown, } } | { "event": "invoke_start", "data": { kind: InvokeKind, } } | { "event": "turn_start", "data": { turn: number, } } | { "event": "turn_end", "data": { turn: number, result: TurnResult, } } | { "event": "llm_call_start", "data": { llm_call: number, } } | { "event": "llm_call_end", "data": { llm_call: number, } } | { "event": "llm_retry", "data": { llm_call: number,
 /**
  * The attempt that just failed. 1 origin.
  */

web/workspace/src/lib/generated/repository-api.ts

@@ -1,6 +1,6 @@
 // @generated by yoi-repository-openapi-typescript@1. Do not edit.
 // Input: openapi/server-api.json
-// Input contract: 0.1.0 (sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052)
+// Input contract: 0.1.0 (sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0)
 // Options: repository-operation-schema-closure,openapi-3.1,format:uint64=safe-number,strict-safe-integers,sorted-output
 // Output: web/workspace/src/lib/generated/repository-api.ts
 // Regenerate/check: cargo run -q -p server-api --example generate_repository_openapi_types -- --check

web/workspace/src/lib/generated/runtime-api.ts

@@ -1,6 +1,6 @@
 // @generated by yoi-runtime-openapi-typescript@1. Do not edit.
 // Input: openapi/server-api.json
-// Input contract: 0.1.0 (sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052)
+// Input contract: 0.1.0 (sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0)
 // Options: runtime-operation-schema-closure,openapi-3.1,strict-integer-ranges,sorted-output
 // Output: web/workspace/src/lib/generated/runtime-api.ts
 // Regenerate/check: cargo run -q -p server-api --example generate_runtime_api_types -- --check

web/workspace/src/lib/generated/ticket-api.ts

@@ -1,6 +1,6 @@
 // @generated by yoi-ticket-browser-openapi-typescript@1. Do not edit.
 // Input: openapi/server-api.json
-// Input contract: 0.1.0 (sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052)
+// Input contract: 0.1.0 (sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0)
 // Options: ticket-objective-merge-request-browser-operation-schema-closure,openapi-3.1,strict-integer-ranges,sorted-output
 // Output: web/workspace/src/lib/generated/ticket-api.ts
 // Regenerate/check: cargo run -q -p server-api --example generate_ticket_api_types -- --check

web/workspace/src/lib/generated/worker-launch-api.ts

@@ -1,6 +1,6 @@
 // @generated by yoi-worker-openapi-typescript@1. Do not edit.
 // Input: openapi/server-api.json
-// Input contract: 0.1.0 (sha256:7b06d005d3436758c96fc4cfd462df76460f89620fd1b58fdf05009d96bb9052)
+// Input contract: 0.1.0 (sha256:49856606e4a16d138cc04a62a6096fd40fff213587b1cbf7f0594f28994a45b0)
 // Options: worker-operation-schema-closure,openapi-3.1,strict-integer-ranges,sorted-output
 // Output: web/workspace/src/lib/generated/worker-launch-api.ts
 // Regenerate/check: cargo run -q -p server-api --example generate_worker_launch_api_types -- --check

web/workspace/src/lib/workspace/console/ConsoleTurnNavigation.svelte

@@ -0,0 +1,166 @@
+<script lang="ts">
+  import type { TurnNavigationItem } from "./turn-navigation";
+
+  type Props = {
+    items: TurnNavigationItem[];
+    hasMore: boolean;
+    loading: boolean;
+    error: string | null;
+    onLoadMore: () => void;
+    onTurnClick: (item: TurnNavigationItem) => void;
+    onTopEdgeChange: (atTop: boolean) => void;
+    historyAvailable?: boolean;
+    element?: HTMLElement | null;
+  };
+
+  let {
+    items,
+    hasMore,
+    loading,
+    error,
+    onLoadMore,
+    onTurnClick,
+    onTopEdgeChange,
+    historyAvailable = true,
+    element = $bindable(null),
+  }: Props = $props();
+
+  function handleScroll(event: Event) {
+    const target = event.currentTarget;
+    if (!(target instanceof HTMLElement)) return;
+    onTopEdgeChange(target.scrollTop <= 1);
+  }
+</script>
+
+<aside class="turn-navigation" aria-label="Conversation turns">
+  <div class="turn-list" bind:this={element} onscroll={handleScroll}>
+    <div class="history-boundary" class:complete={!hasMore && !error && !loading}>
+      {#if !historyAvailable}
+        <span>Earlier history is unavailable for this view</span>
+      {:else if loading}
+        <button type="button" disabled>Loading earlier conversation…</button>
+      {:else if error}
+        <button type="button" onclick={onLoadMore}>Retry earlier conversation</button>
+        <span title={error}>History unavailable</span>
+      {:else if hasMore}
+        <button type="button" onclick={onLoadMore}>Earlier conversation available</button>
+      {:else}
+        <span>Start of conversation</span>
+      {/if}
+    </div>
+
+    {#each items as item (item.turnId)}
+      <button
+        type="button"
+        class="turn"
+        data-turn-id={item.turnId}
+        aria-label={`Jump to conversation: ${item.user}`}
+        onclick={() => onTurnClick(item)}
+      >
+        <span class="bar" aria-hidden="true"></span>
+        <span class="preview">
+          <span class="user-preview">{item.user}</span>
+          {#each item.assistant as line}
+            <span class="assistant-preview">{line}</span>
+          {/each}
+        </span>
+      </button>
+    {/each}
+  </div>
+</aside>
+
+<style>
+  .turn-navigation {
+    min-width: 0;
+    min-height: 0;
+    height: 100%;
+    border-left: 1px solid var(--line);
+    background: color-mix(in srgb, var(--bg-raised) 82%, transparent);
+  }
+
+  .turn-list {
+    height: 100%;
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    padding: var(--space-2) var(--space-2) var(--space-4);
+  }
+
+  .history-boundary {
+    display: grid;
+    gap: 0.2rem;
+    justify-items: center;
+    min-height: 2.25rem;
+    color: var(--text-muted);
+    font-size: var(--font-size-compact);
+    text-align: center;
+  }
+
+  .history-boundary button {
+    border: 0;
+    background: transparent;
+    color: var(--tui-cyan);
+    cursor: pointer;
+    font: inherit;
+    padding: 0.25rem;
+  }
+
+  .history-boundary button:disabled {
+    cursor: wait;
+    opacity: 0.65;
+  }
+
+  .history-boundary.complete::before {
+    content: "";
+    width: 2rem;
+    border-top: 1px solid var(--line);
+  }
+
+  .turn {
+    display: grid;
+    width: 100%;
+    grid-template-columns: 1.6rem minmax(0, 1fr);
+    align-items: center;
+    border: 0;
+    background: transparent;
+    color: inherit;
+    cursor: pointer;
+    padding: 0.42rem 0;
+    text-align: left;
+  }
+
+  .bar {
+    width: 1.1rem;
+    border-top: 3px solid var(--tui-blue);
+    border-radius: 999px;
+    justify-self: center;
+  }
+
+  .preview {
+    display: grid;
+    min-width: 0;
+    gap: 0.12rem;
+  }
+
+  .user-preview,
+  .assistant-preview {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+  }
+
+  .user-preview {
+    color: var(--text);
+    font-size: var(--font-size-compact);
+  }
+
+  .assistant-preview {
+    color: var(--text-muted);
+    font-size: var(--font-size-compact);
+  }
+
+  .turn:focus-visible,
+  .turn:hover {
+    background: color-mix(in srgb, var(--tui-blue) 9%, transparent);
+    outline: none;
+  }
+</style>

web/workspace/src/lib/workspace/console/history.test.ts

@@ -0,0 +1,186 @@
+import type {
+  SessionConversationTurn,
+  SessionHistoryPage,
+  SessionSnapshotEntry,
+} from "$lib/generated/protocol";
+import {
+  applyConsoleHistoryPage,
+  beginConsoleHistoryRequest,
+  type ConsoleHistoryState,
+  conversationTurnPreviews,
+  emptyConsoleHistoryState,
+  historyEntries,
+  setConsoleHistoryTopEdge,
+  shouldLoadHistoryAtTop,
+} from "./history";
+
+declare const Deno: { test(name: string, fn: () => void): void };
+
+function assert(condition: boolean, message: string): void {
+  if (!condition) throw new Error(message);
+}
+
+function message(
+  id: string,
+  role: "user" | "assistant",
+  text: string,
+): SessionSnapshotEntry {
+  return {
+    entry_id: id,
+    timestamp: 1,
+    provenance: role === "user" ? "human_input" : "model_output",
+    kind: "message",
+    role,
+    content: [{ kind: "text", text }],
+  };
+}
+
+function turn(index: number): SessionConversationTurn {
+  return {
+    turn_id: `u-${index}`,
+    entries: [
+      message(`u-${index}`, "user", `question ${index}\nignored`),
+      message(`a-progress-${index}`, "assistant", `working ${index}`),
+      message(
+        `a-final-${index}`,
+        "assistant",
+        `done ${index}\ndetail a\ndetail b\ndetail c`,
+      ),
+    ],
+  };
+}
+
+function page(
+  turns: SessionConversationTurn[],
+  cursor: string | null,
+): SessionHistoryPage {
+  return {
+    session_id: "session-a",
+    lineage_id: "lineage-a",
+    turns,
+    next_cursor: cursor,
+    has_more: cursor !== null,
+  };
+}
+
+Deno.test("history prepends 12 turns as 5 then 5 then 2 without duplicates", () => {
+  let state = emptyConsoleHistoryState();
+  state = beginConsoleHistoryRequest(state, null)!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([8, 9, 10, 11, 12].map(turn), "cursor-8"),
+    null,
+  );
+  state = beginConsoleHistoryRequest(state, "cursor-8")!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([3, 4, 5, 6, 7].map(turn), "cursor-3"),
+    "cursor-8",
+  );
+  state = beginConsoleHistoryRequest(state, "cursor-3")!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([1, 2].map(turn), null),
+    "cursor-3",
+  );
+  assert(state.turns.length === 12, "all real turns must be retained");
+  assert(state.turns[0].turn_id === "u-1", "pages must remain chronological");
+  assert(
+    !state.hasMore && state.cursor === null,
+    "final short page must end history",
+  );
+
+  state = { ...state, requestedCursor: "__initial__", status: "loading" };
+  state = applyConsoleHistoryPage(
+    state,
+    page([8, 9, 10, 11, 12].map(turn), "cursor-8"),
+    null,
+  );
+  assert(
+    state.turns.length === 12,
+    "refresh must dedupe stable turn identities",
+  );
+  assert(
+    historyEntries(state).length === 36,
+    "entries must dedupe by stable identity",
+  );
+});
+
+Deno.test("refresh replaces overlapping latest turns while retaining loaded earlier turns", () => {
+  let state = emptyConsoleHistoryState();
+  state = beginConsoleHistoryRequest(state, null)!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([8, 9, 10, 11, 12].map(turn), "cursor-8"),
+    null,
+  );
+  state = beginConsoleHistoryRequest(state, "cursor-8")!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([3, 4, 5, 6, 7].map(turn), "cursor-3"),
+    "cursor-8",
+  );
+
+  const updated = turn(12);
+  updated.entries.push(message("a-later-12", "assistant", "actually finished"));
+  state = beginConsoleHistoryRequest(state, null)!;
+  state = applyConsoleHistoryPage(
+    state,
+    page([8, 9, 10, 11].map(turn).concat(updated), "stale-cursor-is-ignored"),
+    null,
+  );
+
+  assert(
+    state.turns.length === 10,
+    "refresh must not discard loaded earlier turns",
+  );
+  assert(
+    state.turns.at(-1)?.entries.at(-1)?.entry_id === "a-later-12",
+    "refresh must replace an overlapping turn with its latest committed entries",
+  );
+  assert(
+    state.cursor === "cursor-3",
+    "refresh must retain the oldest paging boundary",
+  );
+});
+
+Deno.test("turn preview uses one user line and final non-empty assistant up to three lines", () => {
+  const preview = conversationTurnPreviews([turn(4)])[0];
+  assert(preview.user === "question 4", "user preview must use its first line");
+  assert(
+    preview.assistant.join("|") === "done 4|detail a|detail b",
+    "preview must choose the final assistant and cap it at three lines",
+  );
+});
+
+Deno.test("top sentinel requests only once until it leaves the edge", () => {
+  let state: ConsoleHistoryState = {
+    ...emptyConsoleHistoryState(),
+    status: "ready",
+    cursor: "older",
+    hasMore: true,
+  };
+  assert(
+    shouldLoadHistoryAtTop(state, true),
+    "armed top edge should request a page",
+  );
+  state = beginConsoleHistoryRequest(state, "older")!;
+  assert(
+    !shouldLoadHistoryAtTop(state, true),
+    "in-flight page must suppress duplicates",
+  );
+  state = {
+    ...state,
+    status: "ready",
+    requestedCursor: null,
+  };
+  assert(
+    !shouldLoadHistoryAtTop(state, true),
+    "stationary sentinel must not drain history",
+  );
+  state = setConsoleHistoryTopEdge(state, false);
+  assert(
+    shouldLoadHistoryAtTop(state, true),
+    "leaving the top must rearm one request",
+  );
+});

web/workspace/src/lib/workspace/console/history.ts

@@ -0,0 +1,228 @@
+import type {
+  SessionConversationTurn,
+  SessionHistoryPage,
+  SessionSnapshotEntry,
+} from "$lib/generated/protocol";
+
+export const CONSOLE_HISTORY_PAGE_TURNS = 5;
+
+export type ConsoleHistoryStatus = "idle" | "loading" | "ready" | "error";
+
+export type ConsoleHistoryState = {
+  sessionId: string | null;
+  lineageId: string | null;
+  turns: SessionConversationTurn[];
+  cursor: string | null;
+  hasMore: boolean;
+  status: ConsoleHistoryStatus;
+  error: string | null;
+  /** Cursor currently in flight; prevents duplicate sentinel requests. */
+  requestedCursor: string | null;
+  /** Rearmed only after leaving the top edge or an explicit user action. */
+  topEdgeArmed: boolean;
+};
+
+export type ConsoleTurnPreview = {
+  turnId: string;
+  lineId: string;
+  user: string;
+  assistant: string[];
+};
+
+export function emptyConsoleHistoryState(): ConsoleHistoryState {
+  return {
+    sessionId: null,
+    lineageId: null,
+    turns: [],
+    cursor: null,
+    hasMore: false,
+    status: "idle",
+    error: null,
+    requestedCursor: null,
+    topEdgeArmed: true,
+  };
+}
+
+export function beginConsoleHistoryRequest(
+  state: ConsoleHistoryState,
+  cursor: string | null,
+): ConsoleHistoryState | null {
+  if (state.status === "loading" || state.requestedCursor !== null) return null;
+  if (cursor !== null && (!state.hasMore || cursor !== state.cursor)) {
+    return null;
+  }
+  return {
+    ...state,
+    status: "loading",
+    error: null,
+    requestedCursor: cursor ?? "__initial__",
+    topEdgeArmed: cursor === null ? state.topEdgeArmed : false,
+  };
+}
+
+export function applyConsoleHistoryPage(
+  state: ConsoleHistoryState,
+  page: SessionHistoryPage,
+  requestedCursor: string | null,
+): ConsoleHistoryState {
+  const requestKey = requestedCursor ?? "__initial__";
+  if (state.requestedCursor !== requestKey) return state;
+
+  const initial = requestedCursor === null;
+  if (
+    !initial &&
+    (state.sessionId !== page.session_id || state.lineageId !== page.lineage_id)
+  ) {
+    return failConsoleHistoryRequest(
+      state,
+      "The conversation changed while earlier history was loading. Retry from the current view.",
+    );
+  }
+
+  const incoming = page.turns.filter((turn) => turn.entries.length > 0);
+  const refreshingSameSession = initial &&
+    state.sessionId === page.session_id &&
+    state.turns.length > 0;
+  const turns = initial
+    ? refreshingSameSession
+      ? mergeRefreshedTurns(state.turns, incoming)
+      : dedupeTurns(incoming)
+    : dedupeTurns([...incoming, ...state.turns]);
+  return {
+    ...state,
+    sessionId: page.session_id,
+    lineageId: page.lineage_id,
+    turns,
+    cursor: refreshingSameSession ? state.cursor : (page.next_cursor ?? null),
+    hasMore: refreshingSameSession ? state.hasMore : page.has_more,
+    status: "ready",
+    error: null,
+    requestedCursor: null,
+  };
+}
+
+export function failConsoleHistoryRequest(
+  state: ConsoleHistoryState,
+  message: string,
+): ConsoleHistoryState {
+  return {
+    ...state,
+    status: "error",
+    error: message.slice(0, 512),
+    requestedCursor: null,
+  };
+}
+
+export function setConsoleHistoryTopEdge(
+  state: ConsoleHistoryState,
+  atTop: boolean,
+): ConsoleHistoryState {
+  if (!atTop && !state.topEdgeArmed) return { ...state, topEdgeArmed: true };
+  return state;
+}
+
+export function shouldLoadHistoryAtTop(
+  state: ConsoleHistoryState,
+  atTop: boolean,
+): boolean {
+  return atTop && state.topEdgeArmed && state.hasMore &&
+    state.status !== "loading" && state.requestedCursor === null;
+}
+
+export function historyEntries(
+  state: ConsoleHistoryState,
+): SessionSnapshotEntry[] {
+  return state.turns.flatMap((turn) => turn.entries);
+}
+
+export function conversationTurnPreviews(
+  turns: readonly SessionConversationTurn[],
+): ConsoleTurnPreview[] {
+  return turns.map((turn) => {
+    const userEntry = turn.entries.find(isUserEntry);
+    const assistants = turn.entries
+      .filter(isAssistantEntry)
+      .map(entryText)
+      .filter((text) => text.trim().length > 0);
+    const assistant = (assistants.at(-1) ?? "")
+      .split(/\r?\n/)
+      .map((line) => line.trim())
+      .filter(Boolean)
+      .slice(0, 3);
+    return {
+      turnId: turn.turn_id,
+      lineId: userEntry?.entry_id ?? turn.turn_id,
+      user: firstNonEmptyLine(userEntry ? entryText(userEntry) : ""),
+      assistant,
+    };
+  });
+}
+
+function mergeRefreshedTurns(
+  retained: readonly SessionConversationTurn[],
+  refreshed: readonly SessionConversationTurn[],
+): SessionConversationTurn[] {
+  const refreshedIds = new Set(refreshed.map((turn) => turn.turn_id));
+  return dedupeTurns([
+    ...retained.filter((turn) => !refreshedIds.has(turn.turn_id)),
+    ...refreshed,
+  ]);
+}
+
+function dedupeTurns(
+  turns: readonly SessionConversationTurn[],
+): SessionConversationTurn[] {
+  const seenTurns = new Set<string>();
+  const seenEntries = new Set<string>();
+  const result: SessionConversationTurn[] = [];
+  for (const turn of turns) {
+    if (seenTurns.has(turn.turn_id)) continue;
+    const entries = turn.entries.filter((entry) => {
+      if (seenEntries.has(entry.entry_id)) return false;
+      seenEntries.add(entry.entry_id);
+      return true;
+    });
+    if (entries.length === 0) continue;
+    seenTurns.add(turn.turn_id);
+    result.push({ ...turn, entries });
+  }
+  return result;
+}
+
+function isUserEntry(entry: SessionSnapshotEntry): boolean {
+  return entry.kind === "user_input" ||
+    (entry.kind === "message" && entry.role === "user");
+}
+
+function isAssistantEntry(entry: SessionSnapshotEntry): boolean {
+  return entry.kind === "message" && entry.role === "assistant";
+}
+
+function entryText(entry: SessionSnapshotEntry): string {
+  switch (entry.kind) {
+    case "user_input":
+      return entry.segments.map((segment) => {
+        if (segment.kind === "text" || segment.kind === "paste") {
+          return segment.content;
+        }
+        if (segment.kind === "file_ref") return `@file ${segment.path}`;
+        if (segment.kind === "uploaded_file") {
+          return `[Attachment: ${segment.file.file_name}]`;
+        }
+        if (segment.kind === "paste_artifact") {
+          return `[Large paste ${segment.artifact.artifact_id}]`;
+        }
+        return "";
+      }).filter(Boolean).join("\n");
+    case "message":
+      return entry.content.map((part) =>
+        part.kind === "text" ? part.text : part.refusal
+      ).join("\n");
+    default:
+      return "";
+  }
+}
+
+function firstNonEmptyLine(value: string): string {
+  return value.split(/\r?\n/).map((line) => line.trim()).find(Boolean) ?? "—";
+}

web/workspace/src/lib/workspace/console/model.test.ts

@@ -2970,3 +2970,113 @@ Deno.test("new invoke resets stats before the next RunEnd", () => {
 
   assertEquals(projection.lines.at(-1)?.body, "0s ・0 reqs ↑0/↓0");
 });
+
+Deno.test("committed assistant identity reconciles the live block without text matching", () => {
+  const lines = projectConsole([
+    {
+      eventId: "user-live",
+      event: {
+        event: "user_message",
+        data: {
+          entry_id: "user-entry",
+          segments: [{ kind: "text", content: "question" }],
+        },
+      },
+    },
+    {
+      eventId: "assistant-live",
+      event: { event: "text_done", data: { text: "final answer" } },
+    },
+    {
+      eventId: "assistant-commit",
+      event: {
+        event: "session_entry_committed",
+        data: {
+          entry: {
+            entry_id: "assistant-entry",
+            timestamp: 7,
+            provenance: "model_output",
+            kind: "message",
+            role: "assistant",
+            content: [{ kind: "text", text: "final answer" }],
+          },
+        },
+      },
+    },
+  ]).lines;
+  assertEquals(lines.filter((line) => line.kind === "assistant").length, 1);
+  assertEquals(
+    lines.find((line) => line.kind === "assistant")?.entryId,
+    "assistant-entry",
+  );
+  assertEquals(
+    lines.find((line) => line.kind === "user")?.entryId,
+    "user-entry",
+  );
+});
+
+Deno.test("committed tool identities reconcile one live call block", () => {
+  const lines = projectConsole([
+    {
+      eventId: "tool-live",
+      event: {
+        event: "tool_call_done",
+        data: { id: "call-1", name: "Read", arguments: '{"file_path":"a"}' },
+      },
+    },
+    {
+      eventId: "tool-call-commit",
+      event: {
+        event: "session_entry_committed",
+        data: {
+          entry: {
+            entry_id: "tool-call-entry",
+            timestamp: 8,
+            provenance: "model_output",
+            kind: "tool_call",
+            call_id: "call-1",
+            name: "Read",
+            arguments: '{"file_path":"a"}',
+          },
+        },
+      },
+    },
+    {
+      eventId: "tool-result-live",
+      event: {
+        event: "tool_result",
+        data: {
+          id: "call-1",
+          summary: "read",
+          output: "contents",
+          is_error: false,
+        },
+      },
+    },
+    {
+      eventId: "tool-result-commit",
+      event: {
+        event: "session_entry_committed",
+        data: {
+          entry: {
+            entry_id: "tool-result-entry",
+            timestamp: 9,
+            provenance: "tool_output",
+            kind: "tool_result",
+            call_id: "call-1",
+            summary: "read",
+            content: "contents",
+            is_error: false,
+          },
+        },
+      },
+    },
+  ]).lines;
+
+  assertEquals(
+    lines.filter((line) => line.toolCall?.id === "call-1").length,
+    1,
+  );
+  assertEquals(lines[0].entryId, "tool-result-entry");
+  assertEquals(lines[0].toolCall?.state, "done");
+});

web/workspace/src/lib/workspace/console/model.ts

@@ -10,6 +10,7 @@ import type {
   InternalWorkerRef,
   InternalWorkerSnapshot,
   Segment,
+  SessionSnapshotEntry,
   WorkerState,
   WorkerStateSnapshot,
   WorkerStatus,
@@ -90,6 +91,8 @@ export type ConsoleLine = {
   compaction?: ConsoleCompaction;
   diff?: ConsoleDiffLine[];
   eventId?: string | null;
+  /** Stable durable identity when this line originates from a committed entry. */
+  entryId?: string;
   source: "event";
   streaming?: boolean;
   error?: boolean;
@@ -279,6 +282,30 @@ export function createConsoleProjector() {
   };
 }
 
+export function mergeCommittedHistoryLines(
+  history: ConsoleLine[],
+  current: ConsoleLine[],
+): ConsoleLine[] {
+  const committed = new Set(
+    history.map((line) => line.entryId).filter((id): id is string =>
+      Boolean(id)
+    ),
+  );
+  return [
+    ...history,
+    ...current.filter((line) => !line.entryId || !committed.has(line.entryId)),
+  ];
+}
+
+export function projectSessionHistoryEntries(
+  entries: SessionSnapshotEntry[],
+  cwd: string | null,
+): ConsoleLine[] {
+  return projectVisibleConsole(
+    snapshotProjectionFromSession("history", { entries }, cwd),
+  ).lines;
+}
+
 function projectVisibleConsole(
   projection: ConsoleProjection,
 ): ConsoleProjection {
@@ -846,14 +873,19 @@ export function applyProtocolEvent(
 
   switch (event.event) {
     case "user_message":
-      next.lines.push(
+      next.lines.push({
-        line(
+        ...line(
           envelope.eventId,
           "user",
           "User",
           segmentsToText(event.data.segments),
         ),
-      );
+        entryId: event.data.entry_id ?? undefined,
+      });
+      break;
+    case "session_entry_committed":
+      reconcileCommittedSessionEntry(next, event.data.entry);
+      applySessionEntry(next, envelope.eventId, event.data.entry);
       break;
     case "system_item":
       next.lines.push(systemItemLine(envelope.eventId, event.data.item));
@@ -1540,6 +1572,7 @@ function readAggregateLine(group: ConsoleLine[]): ConsoleLine {
     toolStatus: hasError ? "failed" : inProgress ? "reading…" : "done",
     detail: calls.map(readDetail).join("\n\n"),
     eventId: group.at(-1)?.eventId,
+    entryId: group.at(-1)?.entryId,
     source: "event",
     streaming: inProgress,
     error: hasError,
@@ -2004,6 +2037,22 @@ function snapshotProjectionFromSession(
   return projection;
 }
 
+function reconcileCommittedSessionEntry(
+  projection: ConsoleProjection,
+  entry: SessionSnapshotEntry,
+): void {
+  if (entry.kind !== "message" || entry.role !== "assistant") return;
+  for (let index = projection.lines.length - 1; index >= 0; index -= 1) {
+    const line = projection.lines[index];
+    if (line.entryId) continue;
+    if (line.kind === "assistant" || line.kind === "in_flight") {
+      projection.lines.splice(index, 1);
+      return;
+    }
+    if (line.kind === "user") return;
+  }
+}
+
 function applySessionEntry(
   projection: ConsoleProjection,
   fallbackEventId: string,
@@ -2011,6 +2060,7 @@ function applySessionEntry(
 ): void {
   if (!isRecord(value)) return;
   const eventId = stringField(value, "entry_id") ?? fallbackEventId;
+  const lineCountBefore = projection.lines.length;
   switch (stringField(value, "kind")) {
     case "user_input":
       projection.lines.push(
@@ -2068,6 +2118,18 @@ function applySessionEntry(
     default:
       break;
   }
+  const entryId = stringField(value, "entry_id");
+  if (entryId) {
+    for (
+      let index = Math.max(0, lineCountBefore - 1);
+      index < projection.lines.length;
+      index += 1
+    ) {
+      if (projection.lines[index].eventId === eventId) {
+        projection.lines[index].entryId = entryId;
+      }
+    }
+  }
 }
 
 function applyLoggedUserInput(

web/workspace/src/lib/workspace/console/turn-navigation.ts

@@ -0,0 +1,10 @@
+import type { SessionConversationTurn } from "$lib/generated/protocol";
+import { type ConsoleTurnPreview, conversationTurnPreviews } from "./history";
+
+export type TurnNavigationItem = ConsoleTurnPreview;
+
+export function buildTurnNavigationItems(
+  turns: readonly SessionConversationTurn[],
+): TurnNavigationItem[] {
+  return conversationTurnPreviews(turns);
+}

web/workspace/src/lib/workspace/console/worker-console.ui.test.ts

@@ -720,7 +720,7 @@ Deno.test("Worker Console renders Edit diffs without preformatted template gaps"
   );
 });
 
-Deno.test("Worker Console exposes a foldable timeline beside the scroll body", async () => {
+Deno.test("Worker Console exposes paged conversation navigation beside the scroll body", async () => {
   const consolePage = await Deno.readTextFile(
     new URL(
       "./../../../routes/w/[workspaceId]/workers/[workerRef]/console/+page.svelte",
@@ -730,28 +730,24 @@ Deno.test("Worker Console exposes a foldable timeline beside the scroll body", a
   const consoleLine = await Deno.readTextFile(
     new URL("./ConsoleLineItem.svelte", import.meta.url),
   );
-  const consoleTimeline = await Deno.readTextFile(
+  const turnNavigation = await Deno.readTextFile(
-    new URL("./ConsoleTimeline.svelte", import.meta.url),
+    new URL("./ConsoleTurnNavigation.svelte", import.meta.url),
   );
   assert(
-    consoleTimeline.includes('class="console-timeline"') &&
+    turnNavigation.includes('class="turn-navigation"') &&
-      consolePage.includes("timelineMarks") &&
+      turnNavigation.includes('class="turn-list"') &&
-      consolePage.includes("jumpToTimelineMark") &&
+      turnNavigation.includes("data-turn-id={item.turnId}") &&
+      turnNavigation.includes('class="user-preview"') &&
+      turnNavigation.includes('class="assistant-preview"') &&
+      turnNavigation.includes("onTopEdgeChange(target.scrollTop <= 1)") &&
+      consolePage.includes("<ConsoleTurnNavigation") &&
+      consolePage.includes("items={turnNavigationItems}") &&
+      consolePage.includes("onTopEdgeChange={handleHistoryTopEdge}") &&
+      consolePage.includes("onTurnClick={jumpToConversationTurn}") &&
+      consolePage.includes('class="conversation-history-boundary"') &&
       consoleLine.includes("data-console-line-id={item.id}") &&
-      consolePage.includes("class:timeline-open={timelineOpen}") &&
+      !consolePage.includes("<ConsoleTimeline"),
-      consolePage.includes('class="timeline-fold"') &&
+    "Worker Console should expose bounded turn navigation with shared paging and transcript jump targets",
-      consolePage.includes("expanded={timelineOpen}") &&
-      !consolePage.includes("{#if timelineOpen}") &&
-      consolePage.includes("handleTimelineRailPointerDown") &&
-      consolePage.includes("projectTimelineAxisPosition") &&
-      consolePage.includes("scrollbar-width: none") &&
-      consoleTimeline.includes("onpointerdown={onRailPointerDown}") &&
-      consoleTimeline.includes("expanded ? 'expanded' : 'folded'") &&
-      consoleTimeline.includes(".timeline-mark.expanded .timeline-card") &&
-      !consoleTimeline.includes("{#if expanded}") &&
-      consoleTimeline.includes(".timeline-thumb") &&
-      consoleTimeline.includes(".timeline-card"),
-    "Worker Console should expose a foldable timeline with scroll and line jump markers",
   );
 });
 

web/workspace/src/routes/w/[workspaceId]/workers/[workerRef]/console/+page.svelte

@@ -4,7 +4,7 @@
     import ConsoleLineItem from "$lib/workspace/console/ConsoleLineItem.svelte";
     import ConsoleDisplayStateView from "$lib/workspace/console/ConsoleDisplayState.svelte";
     import ConsoleTasks from "$lib/workspace/console/ConsoleTasks.svelte";
-    import ConsoleTimeline from "$lib/workspace/console/ConsoleTimeline.svelte";
+    import ConsoleTurnNavigation from "$lib/workspace/console/ConsoleTurnNavigation.svelte";
     import ComposerInput from "$lib/workspace/console/ComposerInput.svelte";
     import type { ComposerDraftSnapshot } from "$lib/workspace/console/composer-draft";
     import {
@@ -28,7 +28,9 @@
         consoleWorkerViews,
         createConsoleProjector,
         isConsoleProjectionEvent,
+        mergeCommittedHistoryLines,
         projectConsoleLines,
+        projectSessionHistoryEntries,
         resolveConsoleViewScrollTop,
         resolveConsoleWorkerView,
         selectConsoleTimelineLines,
@@ -44,6 +46,7 @@
         PendingSubmissionsSnapshot,
         RewindTarget,
         Segment,
+        SessionHistoryPage,
     } from "$lib/generated/protocol";
     import {
         MAX_FILES_PER_SUBMISSION,
@@ -69,6 +72,17 @@
         type WorkerSessionRequestIdentity,
         type WorkerSessionTarget,
     } from "$lib/workspace/session-observation";
+    import {
+        applyConsoleHistoryPage,
+        beginConsoleHistoryRequest,
+        emptyConsoleHistoryState,
+        failConsoleHistoryRequest,
+        historyEntries,
+        setConsoleHistoryTopEdge,
+        shouldLoadHistoryAtTop,
+        type ConsoleHistoryState,
+    } from "$lib/workspace/console/history";
+    import { buildTurnNavigationItems, type TurnNavigationItem } from "$lib/workspace/console/turn-navigation";
     import type { Diagnostic, Worker } from "$lib/workspace/sidebar/types";
 
     type Props = {
@@ -200,6 +214,7 @@
     let timelineOpen = $state(false);
     let consoleViewMode = $state<ConsoleViewMode>("overview");
     let consoleBodyElement: HTMLElement | null = null;
+    let turnNavigationElement = $state<HTMLElement | null>(null);
     let composerInputElement = $state<
         (SvelteComponent & ComposerInputHandle) | null
     >(null);
@@ -222,6 +237,8 @@
     let consoleProjection = $state.raw<ConsoleProjection>(
         consoleProjector.snapshot(),
     );
+    let historyByView = $state.raw<Record<string, ConsoleHistoryState>>({});
+    const pendingHistoryRefreshes = new Set<string>();
     let pendingObservationEvents: ConsoleEventInput[] = [];
     let pendingInitialSnapshotApplication: {
         eventId: string;
@@ -251,9 +268,30 @@
         ),
     );
     const selectedConsoleProjection = $derived(selectedWorkerView.console);
-    const lines = $derived(
+    const selectedHistoryKey = $derived(
+        `${workspaceId}:${runtimeId ?? ""}:${workerId ?? ""}:${selectedWorkerViewSessionId ?? "main"}`,
+    );
+    const selectedHistory = $derived(
+        historyByView[selectedHistoryKey] ?? emptyConsoleHistoryState(),
+    );
+    const currentLines = $derived(
         projectConsoleLines(selectedConsoleProjection.lines, consoleViewMode),
     );
+    const committedHistoryLines = $derived(
+        projectConsoleLines(
+            projectSessionHistoryEntries(
+                historyEntries(selectedHistory),
+                selectedConsoleProjection.cwd,
+            ),
+            consoleViewMode,
+        ),
+    );
+    const lines = $derived(
+        mergeCommittedHistoryLines(committedHistoryLines, currentLines),
+    );
+    const turnNavigationItems = $derived(
+        buildTurnNavigationItems(selectedHistory.turns),
+    );
     const tasks = $derived(selectedConsoleProjection.tasks);
     const timelineLayout = $derived(
         buildTimelineLayout(lines, eventObservedAtVersion, consoleScroll),
@@ -309,6 +347,203 @@
         return response.json() as Promise<T>;
     }
 
+    type WorkerSessionHistoryResponse =
+        | { availability: "page"; page: SessionHistoryPage }
+        | {
+            availability: "unavailable";
+            reason: string;
+            message: string;
+        };
+
+    function mainHistoryKey(target: ConsoleTarget): string {
+        return `${target.workspaceId}:${target.runtimeId}:${target.workerId}:main`;
+    }
+
+    function historyStateFor(key: string): ConsoleHistoryState {
+        return historyByView[key] ?? emptyConsoleHistoryState();
+    }
+
+    function setHistoryState(key: string, state: ConsoleHistoryState) {
+        historyByView = { ...historyByView, [key]: state };
+    }
+
+    async function requestHistoryPage(
+        target: ConsoleTarget,
+        key: string,
+        cursor: string | null,
+        token: number,
+    ) {
+        const started = beginConsoleHistoryRequest(historyStateFor(key), cursor);
+        if (!started) return;
+        setHistoryState(key, started);
+
+        const anchors = cursor === null ? null : captureHistoryAnchors();
+        const query = new URLSearchParams({ limit: "5" });
+        if (cursor) query.set("cursor", cursor);
+        const path = workerApiPath(
+            `/runtimes/${encodeURIComponent(target.runtimeId)}/workers/${encodeURIComponent(target.workerId)}/session/history?${query}`,
+        );
+        try {
+            const response = await fetch(path, {
+                credentials: "same-origin",
+                headers: { accept: "application/json" },
+            });
+            if (response.status === 404 || response.status === 405) {
+                throw new Error("Earlier conversation is not supported by this Runtime version.");
+            }
+            if (!response.ok) {
+                throw new Error(`History request failed (${response.status}).`);
+            }
+            const payload = (await response.json()) as WorkerSessionHistoryResponse;
+            if (token !== reloadToken || mainHistoryKey(target) !== key) return;
+            if (payload.availability === "unavailable") {
+                setHistoryState(
+                    key,
+                    failConsoleHistoryRequest(historyStateFor(key), payload.message),
+                );
+                return;
+            }
+            setHistoryState(
+                key,
+                applyConsoleHistoryPage(historyStateFor(key), payload.page, cursor),
+            );
+            await tick();
+            restoreHistoryAnchors(anchors);
+        } catch (error) {
+            if (token !== reloadToken || mainHistoryKey(target) !== key) return;
+            setHistoryState(
+                key,
+                failConsoleHistoryRequest(
+                    historyStateFor(key),
+                    error instanceof Error ? error.message : String(error),
+                ),
+            );
+        } finally {
+            const refreshAgain = pendingHistoryRefreshes.delete(key);
+            if (
+                refreshAgain &&
+                token === reloadToken &&
+                mainHistoryKey(target) === key
+            ) {
+                void requestHistoryPage(target, key, null, token);
+            }
+        }
+    }
+
+    type HistoryAnchor = { id: string; top: number };
+    type HistoryAnchors = {
+        transcript: HistoryAnchor | null;
+        navigation: HistoryAnchor | null;
+    };
+
+    function captureElementAnchor(
+        container: HTMLElement | null,
+        selector: string,
+        dataKey: "consoleLineId" | "turnId",
+    ): HistoryAnchor | null {
+        const first = container?.querySelector<HTMLElement>(selector);
+        const id = first?.dataset[dataKey] ?? "";
+        return first && id ? { id, top: first.getBoundingClientRect().top } : null;
+    }
+
+    function captureHistoryAnchors(): HistoryAnchors {
+        return {
+            transcript: captureElementAnchor(
+                consoleBodyElement,
+                "[data-console-line-id]",
+                "consoleLineId",
+            ),
+            navigation: captureElementAnchor(
+                turnNavigationElement,
+                "[data-turn-id]",
+                "turnId",
+            ),
+        };
+    }
+
+    function restoreElementAnchor(
+        container: HTMLElement | null,
+        selector: string,
+        anchor: HistoryAnchor | null,
+    ) {
+        if (!anchor || !container) return;
+        const target = container.querySelector<HTMLElement>(selector);
+        if (!target) return;
+        container.scrollTop += target.getBoundingClientRect().top - anchor.top;
+    }
+
+    function restoreHistoryAnchors(anchors: HistoryAnchors | null) {
+        if (!anchors) return;
+        restoreElementAnchor(
+            consoleBodyElement,
+            `[data-console-line-id="${cssEscape(anchors.transcript?.id ?? "")}"]`,
+            anchors.transcript,
+        );
+        restoreElementAnchor(
+            turnNavigationElement,
+            `[data-turn-id="${cssEscape(anchors.navigation?.id ?? "")}"]`,
+            anchors.navigation,
+        );
+        updateConsoleScrollMetrics();
+    }
+
+    function loadEarlierHistory() {
+        const target = consoleTarget;
+        if (!target || selectedWorkerViewSessionId !== null) return;
+        const key = mainHistoryKey(target);
+        const state = historyStateFor(key);
+        if (!state.hasMore || !state.cursor) return;
+        void requestHistoryPage(target, key, state.cursor, reloadToken);
+    }
+
+    function retryHistoryLoad() {
+        const target = consoleTarget;
+        if (!target || selectedWorkerViewSessionId !== null) return;
+        const key = mainHistoryKey(target);
+        const state = historyStateFor(key);
+        void requestHistoryPage(
+            target,
+            key,
+            state.hasMore ? state.cursor : null,
+            reloadToken,
+        );
+    }
+
+    function refreshCurrentHistory() {
+        const target = consoleTarget;
+        if (!target) return;
+        const key = mainHistoryKey(target);
+        if (historyStateFor(key).status === "loading") {
+            pendingHistoryRefreshes.add(key);
+            return;
+        }
+        void requestHistoryPage(target, key, null, reloadToken);
+    }
+
+    function handleHistoryTopEdge(atTop: boolean) {
+        if (selectedWorkerViewSessionId !== null) return;
+        const key = selectedHistoryKey;
+        const state = historyStateFor(key);
+        if (shouldLoadHistoryAtTop(state, atTop)) {
+            loadEarlierHistory();
+        } else if (!atTop) {
+            const rearmed = setConsoleHistoryTopEdge(state, false);
+            if (rearmed !== state) setHistoryState(key, rearmed);
+        }
+    }
+
+    function jumpToConversationTurn(item: TurnNavigationItem) {
+        const line = lines.find((candidate) => candidate.entryId === item.lineId);
+        const target = line
+            ? consoleBodyElement?.querySelector(
+                `[data-console-line-id="${cssEscape(line.id)}"]`,
+            )
+            : null;
+        if (target instanceof HTMLElement) {
+            target.scrollIntoView({ block: "start", behavior: "smooth" });
+        }
+    }
+
     async function loadWorker(target: ConsoleTarget, token: number) {
         workerError = null;
         try {
@@ -489,6 +724,13 @@
         } else if (payload.event === "pending_submissions_changed") {
             pendingSubmissions = payload.data.pending;
         }
+        if (
+            payload.event === "segment_rotated" ||
+            payload.event === "user_message" ||
+            payload.event === "session_entry_committed"
+        ) {
+            refreshCurrentHistory();
+        }
         if (payload.event === "error") {
             queueObservationDiagnostic({
                 code: payload.data.code,
@@ -1093,6 +1335,9 @@
                     ];
                     return;
                 }
+                untrack(() => {
+                    void requestHistoryPage(target, mainHistoryKey(target), null, token);
+                });
                 if (
                     action.kind === "subscribe_live" &&
                     targetWorker &&
@@ -1769,6 +2014,7 @@
         autoFollowConsole = isNearConsoleBottom(consoleBodyElement);
         updateConsoleScrollMetrics();
         rememberConsoleWorkerViewScroll();
+        handleHistoryTopEdge(consoleBodyElement.scrollTop <= 1);
     }
 
     async function scrollConsoleToBottom() {
@@ -1988,19 +2234,7 @@
     {/if}
 
     <div class:with-task-pane={taskPaneOpen} class="console-history">
-        <section class:timeline-open={timelineOpen} class="console-body">
+        <section class="console-body">
-        <div class="console-timeline-spacer" aria-hidden="true"></div>
-        <div class="timeline-fold-cell">
-            <button
-                type="button"
-                class="timeline-fold"
-                aria-expanded={timelineOpen}
-                aria-label={timelineOpen ? "Hide timeline" : "Show timeline"}
-                onclick={() => (timelineOpen = !timelineOpen)}
-            >
-                {timelineOpen ? "Timeline ◂" : "Timeline ▸"}
-            </button>
-        </div>
         <div
             class="console-scroll"
             bind:this={consoleBodyElement}
@@ -2014,6 +2248,24 @@
                     <p class="error">{workerError}</p>
                 {/if}
 
+                {#if selectedWorkerViewSessionId === null && (selectedHistory.hasMore || selectedHistory.error || selectedHistory.status === "loading")}
+                    <div class="conversation-history-boundary">
+                        <button
+                            type="button"
+                            disabled={selectedHistory.status === "loading"}
+                            onclick={selectedHistory.error ? retryHistoryLoad : loadEarlierHistory}
+                        >
+                            {selectedHistory.status === "loading"
+                                ? "Loading earlier conversation…"
+                                : selectedHistory.error
+                                  ? "Earlier conversation unavailable · retry"
+                                  : "Earlier conversation available · load 5 turns"}
+                        </button>
+                    </div>
+                {:else if selectedWorkerViewSessionId === null && selectedHistory.status === "ready"}
+                    <div class="conversation-history-boundary complete">Start of conversation</div>
+                {/if}
+
                 <ConsoleDisplayStateView
                     state={consoleDisplayState}
                     hasContent={lines.length > 0}
@@ -2031,13 +2283,18 @@
             </article>
         </div>
 
-            <ConsoleTimeline
+            <ConsoleTurnNavigation
-                marks={timelineMarks}
+                items={turnNavigationItems}
-                thumbStyle={timelineThumb}
+                hasMore={selectedWorkerViewSessionId === null && selectedHistory.hasMore}
-                axisStyle={timelineAxisStyle}
+                loading={selectedHistory.status === "loading"}
-                expanded={timelineOpen}
+                error={selectedWorkerViewSessionId === null
-                onRailPointerDown={handleTimelineRailPointerDown}
+                    ? selectedHistory.error
-                onMarkClick={jumpToTimelineMark}
+                    : "Earlier history is unavailable for direct SubWorker views."}
+                onLoadMore={selectedHistory.error ? retryHistoryLoad : loadEarlierHistory}
+                onTopEdgeChange={handleHistoryTopEdge}
+                onTurnClick={jumpToConversationTurn}
+                historyAvailable={selectedWorkerViewSessionId === null}
+                bind:element={turnNavigationElement}
             />
         </section>
 
@@ -2446,57 +2703,15 @@
     }
 
     .console-body {
-        --console-timeline-width: 12rem;
-        --console-timeline-fold-width: 2.25rem;
-
         display: grid;
-        grid-template-columns: minmax(0, 1fr) var(--console-timeline-fold-width);
+        grid-template-columns: minmax(0, 1fr) minmax(10rem, 12rem);
-        grid-template-rows: auto minmax(0, 1fr);
         gap: 0 var(--space-3);
         min-height: 0;
         overflow: hidden;
-        transition: grid-template-columns 160ms ease;
-    }
-
-    .console-body.timeline-open {
-        grid-template-columns: minmax(0, 1fr) var(--console-timeline-width);
-    }
-
-    .console-timeline-spacer {
-        grid-column: 1;
-        grid-row: 1;
-    }
-
-    .timeline-fold-cell {
-        grid-column: 2;
-        grid-row: 1;
-        display: flex;
-        justify-content: flex-start;
-        padding-bottom: var(--space-2);
-    }
-
-    .timeline-fold {
-        width: 100%;
-        border: 1px solid var(--line);
-        border-radius: 999px;
-        background: var(--bg-raised);
-        color: var(--text-muted);
-        cursor: pointer;
-        font-size: var(--font-size-compact);
-        font-weight: 800;
-        padding: 0.35rem 0.5rem;
-        text-align: left;
-        white-space: nowrap;
-    }
-
-    .timeline-fold:focus-visible {
-        border-color: var(--tui-cyan);
-        color: var(--text-strong);
     }
 
     .console-scroll {
         grid-column: 1;
-        grid-row: 2;
         height: 100%;
         min-width: 0;
         min-height: 0;
@@ -2510,6 +2725,36 @@
         display: none;
     }
 
+    .conversation-history-boundary {
+        display: flex;
+        justify-content: center;
+        color: var(--text-muted);
+        font-size: var(--font-size-compact);
+        padding-bottom: var(--space-3);
+    }
+
+    .conversation-history-boundary button {
+        border: 0;
+        background: transparent;
+        color: var(--tui-cyan);
+        cursor: pointer;
+        font: inherit;
+    }
+
+    .conversation-history-boundary button:disabled {
+        cursor: wait;
+        opacity: 0.65;
+    }
+
+    .conversation-history-boundary.complete::before,
+    .conversation-history-boundary.complete::after {
+        content: "";
+        align-self: center;
+        width: 2rem;
+        margin: 0 var(--space-2);
+        border-top: 1px solid var(--line);
+    }
+
     .pending-submissions {
         margin: 0 var(--space-3);
         color: var(--muted);

web/workspace/src/routes/w/[workspaceId]/workers/[workerRef]/console/console-display.browser.spec.ts

@@ -106,6 +106,52 @@ function sessionWithUserMessage(content: string): SessionSnapshot {
   };
 }
 
+function emptyHistoryPage() {
+  return {
+    availability: "page",
+    page: {
+      session_id: "session-a",
+      lineage_id: "lineage-a",
+      turns: [],
+      next_cursor: null,
+      has_more: false,
+    },
+  };
+}
+
+function historyPage(indices: number[], cursor: string | null) {
+  return {
+    availability: "page",
+    page: {
+      session_id: "session-a",
+      lineage_id: "lineage-a",
+      turns: indices.map((index) => ({
+        turn_id: `user-${index}`,
+        entries: [
+          {
+            entry_id: `user-${index}`,
+            timestamp: index,
+            provenance: "human_input",
+            kind: "message",
+            role: "user",
+            content: [{ kind: "text", text: `question ${index}` }],
+          },
+          {
+            entry_id: `assistant-${index}`,
+            timestamp: index,
+            provenance: "model_output",
+            kind: "message",
+            role: "assistant",
+            content: [{ kind: "text", text: `done ${index}` }],
+          },
+        ],
+      })),
+      next_cursor: cursor,
+      has_more: cursor !== null,
+    },
+  };
+}
+
 function snapshotEvent(session = emptySession()): ProtocolEvent {
   return {
     event: "snapshot",
@@ -256,12 +302,21 @@ test("applies retained empty and nonempty snapshots before showing their read-on
 });
 
 test("shows bounded initial failures and retries explicitly", async () => {
-  const fetchMock = vi.fn()
+  let sessionRequests = 0;
-    .mockResolvedValueOnce(new Response(null, { status: 503 }))
+  const fetchMock = vi.fn((input: RequestInfo | URL) => {
-    .mockResolvedValueOnce(Response.json({
+    if (String(input).includes("/session/history")) {
-      availability: "retained_snapshot",
+      return Promise.resolve(Response.json(emptyHistoryPage()));
-      snapshot: emptySession(),
+    }
-    }));
+    sessionRequests += 1;
+    return Promise.resolve(
+      sessionRequests === 1
+        ? new Response(null, { status: 503 })
+        : Response.json({
+          availability: "retained_snapshot",
+          snapshot: emptySession(),
+        }),
+    );
+  });
   vi.stubGlobal("fetch", fetchMock);
   render(ConsolePage, { data: pageData() });
 
@@ -271,7 +326,7 @@ test("shows bounded initial failures and retries explicitly", async () => {
   await fireEvent.click(screen.getByRole("button", { name: "Retry" }));
 
   expect(await screen.findByText("No conversation to display")).not.toBeNull();
-  expect(fetchMock).toHaveBeenCalledTimes(2);
+  expect(sessionRequests).toBe(2);
 });
 
 test("distinguishes typed unavailability and an initial live connection closure", async () => {
@@ -327,6 +382,9 @@ test("route changes clear prior content and fence stale Session responses", asyn
   const current = deferred<Response>();
   let firstWorkerLoads = 0;
   const fetchMock = vi.fn((input: RequestInfo | URL) => {
+    if (String(input).includes("/session/history")) {
+      return Promise.resolve(Response.json(emptyHistoryPage()));
+    }
     if (String(input).includes("worker-b")) {
       return current.promise.then((value) => value.clone());
     }
@@ -370,3 +428,185 @@ test("route changes clear prior content and fence stale Session responses", asyn
   expect(screen.queryByText("previous worker content")).toBeNull();
   expect(screen.getByText("current worker content")).not.toBeNull();
 });
+
+test("loads retained conversation turns five at a time into the log and turn bar", async () => {
+  const historyPages = [
+    {
+      availability: "page",
+      page: {
+        session_id: "session-a",
+        lineage_id: "lineage-a",
+        turns: [8, 9, 10, 11, 12].map((index) => ({
+          turn_id: `user-${index}`,
+          entries: [
+            {
+              entry_id: `user-${index}`,
+              timestamp: index,
+              provenance: "human_input",
+              kind: "message",
+              role: "user",
+              content: [{ kind: "text", text: `question ${index}` }],
+            },
+            {
+              entry_id: `assistant-${index}`,
+              timestamp: index,
+              provenance: "model_output",
+              kind: "message",
+              role: "assistant",
+              content: [{ kind: "text", text: `done ${index}` }],
+            },
+          ],
+        })),
+        next_cursor: "older-8",
+        has_more: true,
+      },
+    },
+    {
+      availability: "page",
+      page: {
+        session_id: "session-a",
+        lineage_id: "lineage-a",
+        turns: [3, 4, 5, 6, 7].map((index) => ({
+          turn_id: `user-${index}`,
+          entries: [{
+            entry_id: `user-${index}`,
+            timestamp: index,
+            provenance: "human_input",
+            kind: "message",
+            role: "user",
+            content: [{ kind: "text", text: `question ${index}` }],
+          }],
+        })),
+        next_cursor: "older-3",
+        has_more: true,
+      },
+    },
+    historyPage([1, 2], null),
+  ];
+  let historyRequests = 0;
+  vi.stubGlobal(
+    "fetch",
+    vi.fn((input: RequestInfo | URL) => {
+      if (String(input).includes("/session/history")) {
+        return Promise.resolve(Response.json(historyPages[historyRequests++]));
+      }
+      return Promise.resolve(Response.json({ availability: "live_protocol" }));
+    }),
+  );
+
+  render(ConsolePage, { data: pageData() });
+  await waitFor(() => expect(multiplexer.subscribe).toHaveBeenCalledOnce());
+  latestListener().onFrame(subscribedFrame());
+
+  await waitFor(() =>
+    expect(screen.getAllByText("question 8")).toHaveLength(2)
+  );
+  expect(screen.getAllByText("done 12")).toHaveLength(2);
+  const transcriptScroller = screen.getByLabelText("main transcript")
+    .parentElement as HTMLElement;
+  transcriptScroller.scrollTop = 0;
+  await fireEvent.scroll(transcriptScroller);
+  await waitFor(() =>
+    expect(screen.getAllByText("question 3")).toHaveLength(2)
+  );
+  expect(historyRequests).toBe(2);
+
+  const navigation = screen.getByLabelText("Conversation turns");
+  const navigationList = navigation.firstElementChild as HTMLElement;
+  navigationList.scrollTop = 0;
+  await fireEvent.scroll(navigationList);
+  await fireEvent.scroll(navigationList);
+  transcriptScroller.scrollTop = 0;
+  await fireEvent.scroll(transcriptScroller);
+  await settleMicrotasks();
+  expect(historyRequests).toBe(2);
+
+  await fireEvent.click(
+    screen.getByRole("button", {
+      name: "Earlier conversation available · load 5 turns",
+    }),
+  );
+  await waitFor(() =>
+    expect(screen.getAllByText("question 1")).toHaveLength(2)
+  );
+  expect(screen.getAllByText("Start of conversation")).toHaveLength(2);
+  expect(historyRequests).toBe(3);
+
+  const scrollIntoView = vi.fn();
+  vi.spyOn(HTMLElement.prototype, "scrollIntoView").mockImplementation(
+    scrollIntoView,
+  );
+  await fireEvent.click(
+    screen.getByRole("button", {
+      name: "Jump to conversation: question 8",
+    }),
+  );
+  expect(scrollIntoView).toHaveBeenCalledOnce();
+});
+
+test("keeps live content when history fails and retries the bounded page explicitly", async () => {
+  let historyRequests = 0;
+  vi.stubGlobal(
+    "fetch",
+    vi.fn((input: RequestInfo | URL) => {
+      if (String(input).includes("/session/history")) {
+        historyRequests += 1;
+        return Promise.resolve(
+          historyRequests === 1
+            ? new Response(null, { status: 503 })
+            : Response.json(historyPage([1, 2, 3, 4], null)),
+        );
+      }
+      return Promise.resolve(Response.json({ availability: "live_protocol" }));
+    }),
+  );
+
+  render(ConsolePage, { data: pageData() });
+  await waitFor(() => expect(multiplexer.subscribe).toHaveBeenCalledOnce());
+  latestListener().onFrame(
+    subscribedFrame(sessionWithUserMessage("current response remains")),
+  );
+
+  expect(await screen.findByText("current response remains")).not.toBeNull();
+  await fireEvent.click(
+    await screen.findByRole("button", {
+      name: "Earlier conversation unavailable · retry",
+    }),
+  );
+  await waitFor(() =>
+    expect(screen.getAllByText("question 1")).toHaveLength(2)
+  );
+  expect(historyRequests).toBe(2);
+  expect(screen.getByText("current response remains")).not.toBeNull();
+  expect(screen.getAllByText("Start of conversation")).toHaveLength(2);
+});
+
+test("fences delayed history pages when the selected Worker route changes", async () => {
+  const stale = deferred<Response>();
+  vi.stubGlobal(
+    "fetch",
+    vi.fn((input: RequestInfo | URL) => {
+      const path = String(input);
+      if (path.includes("/session/history")) {
+        return path.includes("worker-b")
+          ? Promise.resolve(Response.json(historyPage([21], null)))
+          : stale.promise;
+      }
+      return Promise.resolve(Response.json({
+        availability: "retained_snapshot",
+        snapshot: emptySession(),
+      }));
+    }),
+  );
+
+  const view = render(ConsolePage, { data: pageData() });
+  await view.rerender({ data: pageData("worker-b", "runtime-b") });
+  await waitFor(() =>
+    expect(screen.getAllByText("question 21")).toHaveLength(2)
+  );
+
+  stale.resolve(Response.json(historyPage([99], null)));
+  await settleMicrotasks();
+  expect(screen.queryByText("question 99")).toBeNull();
+  expect(screen.getAllByText("question 21")).toHaveLength(2);
+});