[juliusmarminge]

ACP Registry instances implement text generation in a hidden session that cancels permission requests and is deleted afterwards; thread titles pass the thread's native session so an agent with session/fork forks it instead of starting cold; Registry joins the text generation fallback order; ACP user docs updated. A separate capability that needs the maintainer's call on ACP execution behavior.

Supersedes #34725. The change is @IEatCodeDaily's; their commits are kept.

Layer 2 of 2, on top of #36513.

[macroscopeapp]

🟠 High server/textGeneration.ts:50

If an ACP agent advertises session deletion but never answers session/delete, this finalizer waits forever, so Effect.scoped never completes and the three-minute request timeout cannot return; the agent process remains retained. deleteSession has no deadline, and finalizers run uninterruptibly, so bound this cleanup independently, as the probe cleanup does.

-        Effect.addFinalizer(() => runtime.deleteSession(sessionId).pipe(Effect.ignore));
+        Effect.addFinalizer(() =>
+          runtime.deleteSession(sessionId).pipe(
+            Effect.timeoutOrElse({ duration: "5 seconds", orElse: () => Effect.void }),
+            Effect.ignore,
+          ),
+        );

🚀 Reply "fix it for me" or copy this AI Prompt for your agent:

In file @packages/provider-acp-registry/src/server/textGeneration.ts around line 50:

If an ACP agent advertises session deletion but never answers `session/delete`, this finalizer waits forever, so `Effect.scoped` never completes and the three-minute request timeout cannot return; the agent process remains retained. `deleteSession` has no deadline, and finalizers run uninterruptibly, so bound this cleanup independently, as the probe cleanup does.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ No successful main baseline artifact is available yet. This run establishes the initial measurement.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	—	5.0 KiB	—	6.8 KiB	✅
Codex	Thread snapshot wire	—	3.8 KiB	—	4.9 KiB	✅
Codex	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Codex	Live turn WebSocket decoded	—	21.5 KiB	—	24.4 KiB	✅
Codex	Live turn messages	—	1	—	8	✅
Claude	Total thread wire	—	5.0 KiB	—	6.8 KiB	✅
Claude	Thread snapshot wire	—	3.8 KiB	—	4.9 KiB	✅
Claude	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Claude	Live turn WebSocket decoded	—	21.9 KiB	—	24.4 KiB	✅
Claude	Live turn messages	—	1	—	8	✅

Other scenarios

No main baseline exists yet for these 64 scenario measurements.

All 64 scenario measurements

Provider	Scenario	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	short turn resume	WebSocket decoded	—	10.5 KiB	—	12.7 KiB	✅
Codex	short turn resume	WebSocket messages	—	2	—	2	✅
Codex	long turn running, cold open	HTTP decoded	—	281.7 KiB	—	302.7 KiB	✅
Codex	long turn running, cold open	rows	—	75	—	75	✅
Codex	long turn running, history page	HTTP decoded	—	92.4 KiB	—	107.4 KiB	✅
Codex	long turn running, history page	rows	—	75	—	75	✅
Codex	long turn finished, cold open	HTTP decoded	—	381.5 KiB	—	410.2 KiB	✅
Codex	long turn finished, cold open	rows	—	151	—	151	✅
Codex	long turn finished, socket cold open	WebSocket decoded	—	381.6 KiB	—	410.2 KiB	✅
Codex	long turn finished, socket cold open	WebSocket messages	—	2	—	2	✅
Codex	long turn finished, socket cold open	rows	—	151	—	151	✅
Codex	long turn finished, work page	HTTP decoded	—	186.2 KiB	—	200.2 KiB	✅
Codex	long turn finished, work page	rows	—	150	—	150	✅
Codex	idle thread resume	WebSocket decoded	—	65 B	—	200 B	✅
Codex	idle thread resume	WebSocket messages	—	1	—	1	✅
Codex	fleet shell snapshot	HTTP decoded	—	42.4 KiB	—	53.7 KiB	✅
Codex	fleet shell snapshot	rows	—	27	—	27	✅
Codex	fleet shell subscribe	WebSocket decoded	—	65 B	—	200 B	✅
Codex	fleet shell subscribe	WebSocket messages	—	1	—	1	✅
Codex	fleet shell resume check	HTTP decoded	—	18 B	—	100 B	✅
Codex	fleet shell resume check	rows	—	0	—	0	✅
Codex	stale shell reload	HTTP decoded	—	42.4 KiB	—	53.7 KiB	✅
Codex	stale shell reload	rows	—	27	—	27	✅
Codex	stale shell resume	WebSocket decoded	—	140 B	—	400 B	✅
Codex	stale shell resume	WebSocket messages	—	2	—	2	✅
Codex	stale todo list cold open	HTTP decoded	—	72.4 KiB	—	83.0 KiB	✅
Codex	stale todo list cold open	rows	—	75	—	75	✅
Codex	stale todo list cold open	nodes	—	2	—	4	✅
Codex	stale todo list cold open	subagents	—	2	—	4	✅
Codex	stale todo list cold open	plans	—	1	—	2	✅
Codex	stale todo list cold open	providerTurns	—	1	—	2	✅
Codex	stale todo list cold open	checkpoints	—	1	—	2	✅
Claude	short turn resume	WebSocket decoded	—	10.6 KiB	—	12.7 KiB	✅
Claude	short turn resume	WebSocket messages	—	2	—	2	✅
Claude	long turn running, cold open	HTTP decoded	—	283.3 KiB	—	302.7 KiB	✅
Claude	long turn running, cold open	rows	—	75	—	75	✅
Claude	long turn running, history page	HTTP decoded	—	93.4 KiB	—	107.4 KiB	✅
Claude	long turn running, history page	rows	—	75	—	75	✅
Claude	long turn finished, cold open	HTTP decoded	—	384.2 KiB	—	410.2 KiB	✅
Claude	long turn finished, cold open	rows	—	151	—	151	✅
Claude	long turn finished, socket cold open	WebSocket decoded	—	384.3 KiB	—	410.2 KiB	✅
Claude	long turn finished, socket cold open	WebSocket messages	—	2	—	2	✅
Claude	long turn finished, socket cold open	rows	—	151	—	151	✅
Claude	long turn finished, work page	HTTP decoded	—	188.1 KiB	—	200.2 KiB	✅
Claude	long turn finished, work page	rows	—	150	—	150	✅
Claude	idle thread resume	WebSocket decoded	—	66 B	—	200 B	✅
Claude	idle thread resume	WebSocket messages	—	1	—	1	✅
Claude	fleet shell snapshot	HTTP decoded	—	43.0 KiB	—	53.7 KiB	✅
Claude	fleet shell snapshot	rows	—	27	—	27	✅
Claude	fleet shell subscribe	WebSocket decoded	—	66 B	—	200 B	✅
Claude	fleet shell subscribe	WebSocket messages	—	1	—	1	✅
Claude	fleet shell resume check	HTTP decoded	—	18 B	—	100 B	✅
Claude	fleet shell resume check	rows	—	0	—	0	✅
Claude	stale shell reload	HTTP decoded	—	43.0 KiB	—	53.7 KiB	✅
Claude	stale shell reload	rows	—	27	—	27	✅
Claude	stale shell resume	WebSocket decoded	—	140 B	—	400 B	✅
Claude	stale shell resume	WebSocket messages	—	2	—	2	✅
Claude	stale todo list cold open	HTTP decoded	—	73.4 KiB	—	83.0 KiB	✅
Claude	stale todo list cold open	rows	—	75	—	75	✅
Claude	stale todo list cold open	nodes	—	2	—	4	✅
Claude	stale todo list cold open	subagents	—	2	—	4	✅
Claude	stale todo list cold open	plans	—	1	—	2	✅
Claude	stale todo list cold open	providerTurns	—	1	—	2	✅
Claude	stale todo list cold open	checkpoints	—	1	—	2	✅

Baseline: unavailable · PR result: ec495ec · 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: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

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

[macroscopeapp]

Approvability

Verdict: Needs Human Approval

Macroscope's review found this PR requires human approval — Registry agents can now generate application text, including through automatic provider fallback, and reuse thread context for titles. The default-routing change requires human review; a separate blocking finding also identifies potentially unbounded session cleanup.

Needs human approval because:

• 1 blocking correctness issue found at or above your repo's Minimum Blocking Severity

^{Adjust the Minimum Blocking Severity for this repo — including turning it Off — in Settings. You can add or adjust custom eligibility rules. Learn more.}