agentHost: recheck Codex hook trust before the first turn

[Dmitriy Vasyura (dmitrivMS)]

Fixes microsoft/vscode-engineering#3840

Summary

• Track the hook trust applied when a fresh Codex thread starts.
• Recheck before the first turn and reuse the existing pre-turn restart path if newly discovered hook hashes require a different grant.
• Carry successful discovery into the replacement without a redundant lookup, revalidate workspace and hook-source trust before startup, and rediscover if the working directory changed.
• Preserve existing grants on a failed recheck, log the failure, and keep Workspace Trust/revocation checks intact.
• Add seven regression cases and document the fresh-workspace requirement. No timeout increase, quarantine, or persistent hook grants.

Root cause and evidence

In a fresh workspace, hooks/list can return no project hooks before thread/start establishes native project trust. The thread then starts without hooks.state, and a model turn can finish successfully without running the synchronous SessionStart marker hook. Incidental pre-turn restarts can mask this ordering problem.

The original failure in build 473136 took 30.450 seconds. Checkout logs confirm the failed attempt and existing passing retry both used d550ca3ed31712f730403f337ce7bcae62aadf1b; the retry is not evidence of a resolving change.

Reproduced with the locked Codex 0.153.0 SDK on main aa513800f750ab6a2edf90d45fa28bfe7e411749. Native controls returned zero hooks before startup and one afterward; restarting with the discovered hash produced the marker in 3/3 controls. The original integration assertions remain unchanged and pass with this fix.

Original provider-internal CI logs were not published, so the historical restart trigger is inferred; the failure mechanism and fix were reproduced locally. This does not claim a common cause for the other timeouts aggregated in the tracker.

Overlapping work

• Overlapping/alternative product fix: agentHost: stabilize trusted Codex workspace hooks #336306. It addresses the same cold-start hook discovery problem and additionally changes cold-resume handling. These PRs should be reconciled rather than merged independently; this draft is the narrower first-turn fix from the build 473136 investigation.
• Quarantine-only alternative: agentHost: disable flaky trusted workspace hook test #336297. This PR keeps the trusted integration case active.
• Related history: agentHost: trust Codex workspace hooks per thread #334063, Codex agent-host: project hooks (.codex/hooks.json) silently don't run in the Agents window (per-hook trust not granted) #331733, and codex hooks do not get run #331285. The latter two issues are already closed; agentHost: trust Codex workspace hooks per thread #334063 introduced the pre-start hook lookup and test. They are context, not additional closing targets.

Searches of open VS Code hook, Codex, Workspace Trust, and exact-marker reports found no additional open issue that this patch can confidently close.

Validation

Windows, Electron 42.10.0, locked Codex 0.153.0:

• Targeted transpilation and scoped TypeScript checking of changed modules/dependencies: passed.
• scripts\test.bat --run src\vs\platform\agentHost\test\node\codex\codexCreateChat.test.ts: 98 passing.
• scripts\test-integration.bat --run src\vs\platform\agentHost\test\node\providerIntegration\codexCustomizations.integrationTest.ts: 6 passing (five provider cases plus the harness check).
• Repository hygiene on changed files and git diff --check: passed.

No full build, CI rerun, or Linux/macOS validation was performed.

[Copilot]

Copilot review overview

🟡 Changes recommended

Replacement materialization can discard a successful recheck when its redundant hook lookup fails.

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Review tier: Balanced
Findings: 1

Open (1)

• Carry the successful hook recheck into the replacement · New

What changed in this PR

Adds a first-turn Codex hook-trust recheck to address cold-start hook discovery.

Changes:

• Tracks applied hook trust and restarts when discovered hashes change.
• Adds four regression cases covering discovery, failure, and revocation.
• Documents fresh-workspace integration-test requirements.

File	Description
codexAgent.ts	Implements hook-trust tracking and rechecking.
codexCreateChat.test.ts	Adds first-turn trust regression tests.
providerIntegration/​README.md	Documents Codex hook test isolation.

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