[jakeleventhal]

Planned worktree handoffs currently end the old provider stream as a failure, which holds the continuation. Persisting the binding and continuation separately also lets a delegated child publish its result before the follow-up is queued.

The handoff now commits the workspace binding, continuation, checkpoint scope, and detach intent together. A typed workspace-change signal interrupts only the moving thread, including before its first provider turn. Shared-session siblings stay alive; open tools finish as interrupted. Normal finalization starts the continuation in the destination worktree. Explicit Stop and real provider failures still hold queued input.

Maintainer rebuild of @jakeleventhal’s #15203, preserving the author’s commits. @timvdhoorn identified the unfinished root-tool issue retained in this fix. The original 11 added executable test cases were reduced to three behavior tests; subscription ownership reuses the existing subscriber map.

Verification:

• Four focused files: 185 original cases → 177, all passing (current main has 174). Atomic-persistence and detach-reason revert controls fail by assertion. The original shared-session path also fails the retained integration assertion.
• Both existing exclusive/shared handoff cases also suspend startup after the event consumer forks, then prove the real outbox cannot claim the detach until startup finishes. This addresses the reported startup race without adding a production gate.
• Two fresh whole-PR review rounds from both reviewers found no remaining actionable issues.
• Existing provider-error, Stop, startup and shutdown queue controls pass. Independent review also ran the complete adjacent queue/control and thread deletion/settlement suites.
• Scoped server, provider-core and contracts typechecks, lint, formatting and diff checks pass.
• Full isolated backend with actual Codex: a parent and delegated child shared one provider session; the child handoff interrupted its old run/tool, automatically resumed, wrote the destination cwd, and checkpointed the new file. The parent completed after exactly one child-result transfer. Replaying the accepted handoff command kept two runs and five messages unchanged.
• Headless backend before/after proof.

Current-head CI passes, including the full web rerun. Two earlier attempts failed the same unchanged highlighting assertion; its focused three browser cases pass on both head and base. Macroscope Correctness passes; Approvability remains neutral pending human review of the lifecycle change.

This is backend lifecycle behavior with no rendering change. Live proof covers Codex on headless Linux. Exclusive-session behavior has deterministic integration coverage; live Claude, Cursor, Grok, OpenCode, Antigravity, macOS, Windows, iOS, Android and Electron desktop remain unverified. The optional continuation command field adds no client entry point or permission.

Implementation and live verification: GPT-6.1 Sol; tests: GPT-6 Astra; adversarial reviews: Claude Opus 5.5 and GPT-6 Sol. Harness: T3 Code with Codex and Claude.

[macroscopeapp]

Approvability

Verdict: Approved at 9af09ed

Macroscope's review found this PR approvable — Worktree handoffs now save requested continuations before detaching the current session and cleanly finalize interrupted streaming work. The change restores existing opt-in behavior, with thread-scoped detach handling and Stop safeguards limiting its impact.

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Reviewing files that changed from the base of the PR and between 9af09ed and 26e8078.

Files selected for processing: 7

• apps/server/src/orchestration-v2/Orchestrator.ts
• apps/server/src/orchestration-v2/ProviderSessionManager.test.ts
• apps/server/src/orchestration-v2/ProviderSessionManager.ts
• apps/server/src/orchestration-v2/RunExecutionService.ts
• docs/internals/overview.md
• packages/contracts/src/orchestrationV2.ts
• packages/provider-core/src/server/ProviderAdapter.ts

Files skipped from review as they are similar to previous changes: 1

• docs/internals/overview.md

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Walkthrough

Worktree handoffs now include continuation data in the metadata update. The orchestrator validates and queues the continuation, and workspace-change detach events interrupt the matching run. Tests and documentation cover handoff timing, detach handling, and continuation behavior.

Changes: Worktree handoff and continuation

Layer / File(s)	Summary
Dispatch the binding and continuation packages/contracts/src/orchestrationV2.ts, apps/server/src/mcp/WorktreeMcpService.ts, apps/server/src/orchestration-v2/Orchestrator.ts, apps/server/src/mcp/WorktreeMcpService.test.ts	The metadata update accepts continuation data, validates and queues it with the worktree binding, and derives delivery status from stored events. Tests cover queued and started delivery, dispatch failure, and interruption handling.
Propagate planned detach interruptions packages/provider-core/src/server/ProviderAdapter.ts, apps/server/src/orchestration-v2/EffectOutbox.ts, apps/server/src/orchestration-v2/EffectWorker.ts, apps/server/src/orchestration-v2/ProviderSessionManager.ts, apps/server/src/orchestration-v2/RunExecutionService.ts, apps/server/src/orchestration-v2/ProviderSessionManager.test.ts, apps/server/src/orchestration-v2/RunExecutionService.test.ts	Detach effects carry the workspace_changed reason. Thread-scoped event subscriptions receive a typed detach error, which run execution handles by interrupting open root items and the matching run. Tests cover detach handling and event subscriptions.
Verify handoff and queued-input behavior apps/server/src/orchestration-v2/SelectionRestart.integration.test.ts, apps/server/src/orchestration-v2/testkit/ProviderReplayHarness.ts, docs/internals/overview.md, docs/user/composer.md	Integration tests cover provider switching and delegated handoffs with exclusive and shared sessions. The test harness accepts an MCP app model context layer. Documentation describes handoff ordering and queued-message behavior.

Priority: Normal

Estimated code review effort: 4 (Complex) | ~45 minutes

Change: Bug fix · Severity of issue fixed: Medium

Sequence Diagram(s)

sequenceDiagram
  participant WorktreeMcpService
  participant Orchestrator
  participant EffectWorker
  participant ProviderSessionManager
  participant RunExecutionService
  WorktreeMcpService->>Orchestrator: Dispatch metadata update with binding and continuation
  Orchestrator->>Orchestrator: Validate update and queue continuation
  EffectWorker->>ProviderSessionManager: Detach session with workspace_changed reason
  ProviderSessionManager->>RunExecutionService: Publish ProviderAdapterSessionDetached
  RunExecutionService->>RunExecutionService: Interrupt the matching run

Loading

Possibly related issues

• pingdotgg/t3code#22971: Reports that a worktree handoff can end as a provider failure without starting the queued continuation; this PR changes the planned-detach and continuation path.
• pingdotgg/t3code#24513: Reports user-stop attribution for a successful Codex handoff; this PR changes detach intent and run settlement, though the summaries do not establish that it changes the displayed label.

Possibly related PRs

• pingdotgg/t3code#24444: Addresses continuation admission after a worktree handoff detaches the old provider session.
• pingdotgg/t3code#15782: Adds workspace-binding checks used by worktree handoffs.
• pingdotgg/t3code#24545: Changes run finalization for the interruption caused by a workspace handoff.

Suggested labels: bugfix

Suggested reviewers: juliusmarminge

Merge Risk: Minimal · up to 26e80

The identified handoff risks are addressed at the reviewed head. No actionable merge-blocking issue remains after normal checks.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 55e45

The handoff now records its follow-up message together with the workspace change and checks thread/session identity before resuming. No new access-control bypass was established, but shared-session recovery and rollback workspace selection remain incompletely verified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The reachable public operation requires authenticated environment-level orchestration authority and targets one thread per command. Repetition is not bounded to one thread by that scope check; project or tenant isolation beyond the environment boundary was not established by this review.

Trust Boundaries and Controls

• observed — Websocket upgrade authenticates the session, and RPC middleware requires orchestration-operate scope before command handling. The inspected revision comparison shows no change to these enforcement files.
• observed — The new public payload is converted into an agent/MCP message with no attachments and queued delivery. The previous handoff used the same agent/MCP provenance through sendToThread. The payload does not carry notification or delegated-completion fields, whose separate provenance controls remain enforced.

Resilience and Maintainability Implications

• observed — Queue scheduling refuses held queued input and retains recovery gating after non-validation provider failures. Focused integration tests cover planned handoff ordering, early exclusive-session detach, explicit Stop and provider-failure controls.
• observed — The new typed subscriber failure is sent when an exclusive session is released. Shared multi-thread sessions instead unload native threads without that signal. Codex unload requests thread unsubscribe; OpenCode2 unload returns without cleanup for active or background work. Equivalent terminalization, especially before native thread identity exists, remains unproven. The manager's shared unload branch predates this PR.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly and concisely describes the main change: resuming continuations after planned worktree handoffs.
Description check		The description covers the problem, implementation, scope and maintainer approval context, verification results, limitations, and test evidence. It is complete despite not using every template heading…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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Explanation

The description covers the problem, implementation, scope and maintainer approval context, verification results, limitations, and test evidence. It is complete despite not using every template heading verbatim.

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Actionable comments posted: 2

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Inline comments:
Review comments at @apps/server/src/orchestration-v2/Orchestrator.ts:
- Line 9549: Update the cwd fallback passed to dispatchMessage so
projection.thread.worktreePath takes precedence over
selectedProviderSession?.cwd when runtimePolicy.resolve provides no cwd; keep
process.cwd() as the final fallback so queued continuation checkpoints use the
current worktree.

Review comments at @apps/server/src/orchestration-v2/ProviderSessionManager.ts:
- Around line 2032-2034: Update the shared-session detach handling around
expectedDetach to send a ProviderAdapterSessionDetached signal to the subscriber
for input.threadId even when activeTurns is empty; do not fail subscribers
belonging to other attached threads.

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Reviewing files that changed from the base of the PR and between 17801ba and 55e454a.

📒 Files selected for processing (4)

• apps/server/src/orchestration-v2/EffectWorker.ts
• apps/server/src/orchestration-v2/Orchestrator.ts
• apps/server/src/orchestration-v2/ProviderSessionManager.ts
• packages/contracts/src/orchestrationV2.ts

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[timvdhoorn]

Thanks for this PR. I've been running it locally (ported onto nightly 0.0.46-nightly.20261015.3158) and the continuation now starts after t3_worktree_handoff. I hit one leftover issue and wanted to share a fix.

Issue: the t3_worktree_handoff tool call stays running in the interrupted run, so the timeline keeps showing it as waiting. The planned detach ends the provider stream before the Claude adapter's finalizeActiveTurn → endToolCalls runs, and the synthesized terminal in RunExecutionService only covers the provider turn. I saw this on every handoff: three threads, each with the handoff call still running in an interrupted run.

Fix: keep track of the root turn's open items. When the planned detach happens, emit them as interrupted before the synthesized terminal, the same way the adapter handles a normal Stop. Subagent items are left out because the run-owned subagent cascade already ends them.

@@ -939,6 +939,11 @@ export const layer: Layer.Layer<
           const latestTurnItemOrdinal = yield* Ref.make(input.providerTurnOrdinal * 100);
           const latestProviderThread = yield* Ref.make(input.providerThread);
           const latestRootProviderTurn = yield* Ref.make<OrchestrationV2ProviderTurn | null>(null);
+          // Root items still open, so a planned detach can end the calls whose
+          // results the detached provider session will never report.
+          const openRootTurnItems = yield* Ref.make<ReadonlyMap<TurnItemId, OrchestrationV2TurnItem>>(
+            new Map(),
+          );
           const routeIdentity: ProviderEventRouteIdentity = {
             threadId: input.run.threadId,
             runId: input.run.id,
@@ -1277,7 +1282,18 @@ export const layer: Layer.Layer<
                             }
                           : state,
                       );
+                      const openItems = [...(yield* Ref.getAndSet(openRootTurnItems, new Map())).values()];
                       return Stream.fromIterable<ProviderAdapterV2Event>([
+                        ...openItems.map((turnItem) => ({
+                          type: "turn_item.updated" as const,
+                          driver: input.providerThread.driver,
+                          turnItem: {
+                            ...turnItem,
+                            status: "interrupted" as const,
+                            completedAt,
+                            updatedAt: completedAt,
+                          },
+                        })),
                         ...(providerTurn?.status === "running" || providerTurn?.status === "pending"
                           ? [
                               {
@@ -1378,6 +1394,18 @@ export const layer: Layer.Layer<
                   yield* Ref.update(latestTurnItemOrdinal, (current) =>
                     Math.max(current, event.turnItem.ordinal),
                   );
+                  const turnItem = event.turnItem;
+                  // Subagent rows end through the run-owned subagent cascade.
+                  if (turnItem.type !== "subagent") {
+                    const open = turnItem.status === "running" || turnItem.status === "pending";
+                    yield* Ref.update(openRootTurnItems, (items) => {
+                      if (!open && !items.has(turnItem.id)) return items;
+                      const next = new Map(items);
+                      if (open) next.set(turnItem.id, turnItem);
+                      else next.delete(turnItem.id);
+                      return next;
+                    });
+                  }
                 }
                 if (event.type === "turn.terminal") {
                   yield* Ref.set(terminalEvent, event);

Test (in RunExecutionService.test.ts): send a running root dynamic_tool item, then ProviderAdapterSessionDetached, and check that the item is ingested as interrupted. To see what gets ingested, the captureRootRunTermination helper now records the items passed to ingestNormalized in a separate ingested list. The test fails without the change and passes with it.

[jakeleventhal]

@timvdhoorn Thanks for the detailed report and proposed fix. You're right: the planned-detach path interrupted the provider turn without ending its open root tool items.

Fixed in 19f7ff9. It tracks pending/running root items and emits their interrupted updates before the synthesized terminal. Completed items are removed from tracking, and subagent items stay with the existing run-owned cascade.

Added regression coverage for pending and running tools, multiple open items, already-completed items, event ordering, and subagent cleanup without duplicate terminal updates. The two root-tool cases fail before the fix and pass after it. All 120 tests across RunExecutionService.test.ts, SelectionRestart.integration.test.ts, and WorktreeMcpService.test.ts pass; server typecheck, scoped lint, formatting, and git diff --check also pass. I haven't run a live Claude session.

Model and harness: GPT-6.1 Sol (HIGH), T3 Code through the Codex harness.

[juliusmarminge]

Taking over this one as maintainer for batch worktree-git-17. I will keep this PR and preserve your commits, reduce the regression and implementation scope, and fix the shared-session detach path before independent reviews. Atomic continuation persistence and real-provider verification remain acceptance gates. No merge is planned.

[Chinoman10]

Additional Pi evidence: successful handoff, held continuation

Observed 2026-11-02 on Linux, a locally patched T3 0.1.4 runtime (0.1.4-owner-credentials.1), provider driver pi, model openai-codex/gpt-6.1-sol (not the native Codex driver). This is a live-session observation, not a clean stock-upstream reproduction.

• t3_worktree_handoff with an explicit continuation, startFromOrigin: true, and runSetupScript: false successfully created/bound a clean destination worktree.
• At 16:31:26.352Z, the outgoing run failed: ProviderAdapterEventStreamError, caused by Error: Workspace changed. The UI showed the generic unexpected event-stream-close error.
• At 16:31:26.989Z, the continuation was queued. Later read-only inspection found queueHeld: true, startedAt: null, and no active run. The continuation was preserved, not lost, but did not automatically start.
• The persisted provider-session record retained the old project-root cwd; the thread's worktreePath pointed to the new clean worktree. Pi advertised supportsMultipleProviderThreadsPerSession: false.

The additional coverage is Pi also exhibiting the held-continuation failure, rather than only a false error followed by successful continuation. No candidate PR was applied or live-tested for this observation; it does not establish a verified fix or full losslessness.

Your typed intentional-detach/atomic-continuation approach appears to target this mechanism, but applicability is a source/state inference, not a Pi candidate test. Could you assess/add a Pi single-thread-session regression proving exactly one continuation starts in the destination, the old tool/run has no false provider error or stale running item, and genuine provider failure/explicit Stop still hold queued work? Related evidence: #21573 and #22971; alternative queue-side proposal: #24444.

Posted by GPT-6.1 Sol through Pi/T3, with the account owner's explicit authorization; diagnostic excerpts are sanitized.

[michael0903]

Still reproduces on 0.1.8-nightly.20261106.4262 (macOS, Claude provider). A Claude thread that calls t3_worktree_handoff with a continuationPrompt ends its turn with "The provider event stream closed unexpectedly", and the queued continuation then sits held until Resume is clicked by hand. This happened on several handoffs today, so the bug is still live on current nightlies.