fix(server): stop Codex threads with queued follow-ups

[t3dotgg]

Codex stop requests failed when a thread had a queued follow-up. T3 replaced the active provider turn ID with the queued turn ID, so Codex rejected the interrupt.

Keep the existing active turn ID until Codex sends turn lifecycle notifications that advance it. The integration test reproduces the observed active and queued turn ordering.

Test: vp test run apps/server/src/provider/Layers/CodexCollabRuntime.integration.test.ts

Created by GPT-5.6 in T3 Code using the Codex harness.

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Note

Medium Risk
Changes turn-tracking used by Stop/interrupt on the Codex provider path; scope is narrow and covered by a new integration test, but incorrect active-turn bookkeeping could still break interrupt behavior.

Overview
Stop on Codex threads failed when a follow-up was queued while the current turn was still running: each turn/start response overwrote activeTurnId with the queued turn id, but Codex turn/interrupt only accepts the currently active turn.

sendTurn now keeps the existing activeTurnId when Codex returns a queued follow-up (session.activeTurnId ?? turnId); lifecycle handlers (turn/started / turn/completed) still advance or clear it. updateSession accepts an updater function so that logic can read the prior session state.

Adds an integration test (two sendTurn calls, then interruptTurn) and extends the collab mock peer with per-call turn ids, optional suppression of a second turn/started, and interrupt validation when the wrong turn id is sent.

^{Reviewed by Cursor Bugbot for commit 84f5321. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Fix interruptTurn to target the active turn when Codex has a queued follow-up

• When Codex accepts a queued follow-up via turn/start, session.activeTurnId was being overwritten with the new (queued) turn id, causing subsequent interrupts to target the wrong turn.
• Fixes this by switching updateSession calls in the turn/start flow to a functional form that preserves the existing activeTurnId if one is already set.
• Extends codexCollabMockPeer.mjs to support deterministic turn ids, suppressing turn/started for queued turns, and validating interrupt targets.
• Adds an integration test in CodexCollabRuntime.integration.test.ts that reproduces the bug and asserts the interrupt targets the first (active) turn id.

📊 Macroscope summarized 84f5321. 2 files reviewed, 0 issues evaluated, 0 issues filtered, 0 comments posted

🗂️ Filtered Issues

No issues evaluated.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	11.3 KiB	11.3 KiB	+8 B (+0.1%)	15.1 KiB	✅
Codex	Thread snapshot wire	5.5 KiB	5.5 KiB	−5 B (−0.1%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	5.9 KiB	5.9 KiB	+13 B (+0.2%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	49.7 KiB	49.7 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	16	16	0 (0.0%)	21	✅
Claude	Total thread wire	11.3 KiB	11.3 KiB	−7 B (−0.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	5.5 KiB	5.5 KiB	−7 B (−0.1%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	5.9 KiB	5.9 KiB	0 B (0.0%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	50.6 KiB	50.6 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	16	16	0 (0.0%)	21	✅

Baseline: 49964e3 · PR result: 84f5321 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 94.6 KiB
• Claude decoded thread snapshot: 95.4 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Approved 84f5321

Straightforward bug fix that preserves the active turn ID when Codex queues a follow-up, ensuring interrupt targets the correct turn. Change is small, self-contained, and includes a comprehensive integration test.

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