fix(agent-hooks): cap Windows managed-hook stdin stalls at 2s host budget

[brennanb2025]

Summary

• Root cause on Windows Claude: both more.com and curl payload@- can wait indefinitely for stdin EOF; curl --max-time does not cover that read.
• Cap only local Windows Claude hooks at a 2-second host budget. POSIX, SSH/WSL, OpenClaude, and every other provider keep the existing 10-second budget.
• Preserve the [Bug]: Generated agent hook scripts exit without draining stdin → per-tool-call "failed to write hook stdin: Broken pipe (os error 32)" #8419 full-drain contract (more.com) and the existing form-encoded curl body/token contract. This is a bounded mitigation, not a claim that the underlying batch read is now bounded.

Why not replace the reader?

Real Windows probing found no lower-risk batch-only replacement:

• curl -T - still exceeded 3 seconds with held-open stdin against a reachable endpoint.
• Against an unavailable endpoint it exited in ~0.56 seconds but produced writer-side EOF, regressing [Bug]: Generated agent hook scripts exit without draining stdin → per-tool-call "failed to write hook stdin: Broken pipe (os error 32)" #8419.
• Closed-input form and upload variants both preserved the exact 200 KB UTF-8 payload.
• PowerShell draining cost 295–372 ms per normal hook (339 ms median), and an attempted bounded async read still remained alive past 3 seconds.

Keeping the established readers and narrowing the host backstop avoids routine 10–12 second Claude stalls without adding hundreds of milliseconds to every healthy hook or changing other providers.

Windows evidence

Case	Existing 10s host budget	Final Windows Claude budget
more.com, held-open stdin	still running at 8,012 ms	host kill ~2,035 ms
curl payload@-, held-open stdin	still running at 8,007 ms	host kill ~2,032 ms
curl, closed stdin / unavailable endpoint	~723 ms	~703 ms
missing Orca env, held-open stdin	~51 ms	~53 ms
more.com, closed stdin	86–129 ms	~63–98 ms

Independent final-head probing also confirmed form success at 79–150 ms, unavailable-endpoint completion at 561–588 ms, exact UTF-8 body fidelity, no writer error for the retained form path, and writer EOF for the rejected curl -T - alternative.

Tests

• Windows low-spec, exact head: 22 passed / 1 intentional skip across the Windows stdin-bound, all-provider timeout, and Claude install suites.
• Local focused run: 20 passed / 3 platform skips.
• pnpm tc passed.
• Touched-file oxlint/oxfmt passed.
• Windows install regeneration asserts Claude becomes 2 seconds while OpenClaude remains 10 seconds; global provider/SSH timeout coverage remains unchanged.

AI Review Report

• Orca-native same-model high review audited the complete diff, issue fit, stdin behavior, cross-provider/SSH scope, performance, and Windows evidence.
• It found one scope leak where OpenClaude inherited the 2-second timeout; fixed in dc6826665c with an explicit Windows regression assertion.
• No other actionable findings remained.

Security Audit

• No new executable lookup, endpoint, token, auth, remote-wire, or payload-format surface.
• Existing fully-qualified Windows system binaries and hook token header are unchanged.

Screenshots

No visual change.

Closes #13285 · STA-3729

[coderabbitai]

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📝 Walkthrough

Walkthrough

The change documents Windows stdin-draining and timeout behavior for managed hooks. It adds a two-second timeout for Windows Claude hooks and passes the optional timeout through managed-hook installation. Windows tests cover timeout values, environment handling, stdin draining, curl command construction, installed scripts, Devin handling, and temporary-resource cleanup.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes lower the Windows host timeout to 2 seconds, preserve stdin draining and hook behavior, and add regression coverage for the linked issue objectives.
Out of Scope Changes check	✅ Passed	The code, documentation, timeout wiring, fixtures, and tests are directly related to the Windows managed-hook stdin stall objectives.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title clearly identifies the Windows managed-hook stdin stall fix and the new two-second host budget.
Description check	✅ Passed	The description covers the summary, testing, AI review, security audit, screenshots, platform scope, risks, and linked issue; Notes is not explicit but key details are included.

✨ Finishing Touches

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• Create stacked PR
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