Forward CMUX_SOCKET_CAPABILITY to Pi hook children

[mrohan-sq]

Context

Workspace auto-naming never fires for Pi sessions, even with automation.workspaceAutoNaming enabled and healthy Stop hooks. The detached naming pass exits silently before its first socket call.

Summary

• Forward CMUX_SOCKET_CAPABILITY to cmux CLI hook children in the Pi extension.
• The orphaned auto-name pass (sh -c '... &') fails ancestry-based socket auth without it.
• Verified end-to-end: probe rejected without the capability, rename succeeds with it forwarded.

Dependencies

None.

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Summary by cubic

Forward CMUX_SOCKET_CAPABILITY to Pi hook children of the cmux CLI so the detached auto-name pass can authenticate. Restores workspace auto-naming for Pi sessions that previously exited before the first probe due to missing credentials.

^{Written for commit 0955941. Summary will update on new commits.}

Summary by CodeRabbit

• Bug Fixes
  • Improved socket authentication for detached and automatically named command-line processes by forwarding the required socket capability information alongside existing credentials.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 249d0ff and 0955941.

📒 Files selected for processing (1)

• CLI/CMUXCLI+PiExtensionSourcePart1.swift

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📝 Walkthrough

Walkthrough

Changes

Socket authentication

Layer / File(s)	Summary
Forward socket credentials CLI/CMUXCLI+PiExtensionSourcePart1.swift	hookEnvironment now forwards CMUX_SOCKET_CAPABILITY with CMUX_SOCKET_PASSWORD to authenticated cmux CLI child processes.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Suggested reviewers: austinywang, lawrencecchen

🚥 Pre-merge checks | ✅ 25

✅ Passed checks (25 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main change: forwarding CMUX_SOCKET_CAPABILITY to Pi hook children.
Description check	✅ Passed	The description clearly explains the problem, fix, rationale, dependencies, and end-to-end verification, but it omits several template sections.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Cmux Swift Actor Isolation	✅ Passed	The diff only changes JavaScript text inside the existing Swift raw-string property; it adds no Swift models, protocols, Sendable references, UI access, or actor-isolation boundary.
Cmux Swift Blocking Runtime	✅ Passed	The patch only forwards CMUX_SOCKET_CAPABILITY and updates comments in an embedded TypeScript source string; it adds no semaphore, wait, sleep, polling, sync, timer, or lock.
Cmux Browser Automation Off-Main	✅ Passed	The PR only changes Pi hook environment forwarding in CLI/CMUXCLI+PiExtensionSourcePart1.swift; it adds no browser.* command or WebKit/AppKit routing change.
Cmux Expensive Synchronous Load	✅ Passed	The commit only forwards CMUX_SOCKET_CAPABILITY in embedded Pi TypeScript; it adds no agent-history load, large-file parse, directory scan, or main-actor synchronous work.
Cmux Cache Substitution Correctness	✅ Passed	The diff only forwards CMUX_SOCKET_CAPABILITY in hookEnvironment; it does not replace an authoritative read with a cache or alter persistence, history, undo, or snapshot logic.
Cmux No Hacky Sleeps	✅ Passed	The diff only forwards CMUX_SOCKET_CAPABILITY and updates comments. It adds no sleep, timer, polling, fixed delay, or wall-clock synchronization.
Cmux Algorithmic Complexity	✅ Passed	The diff adds only two constant-time environment lookups and assignments inside existing hook setup; it adds no collection scan, sort, filter, join, or batch algorithm.
Cmux Swift Concurrency	✅ Passed	The diff only forwards CMUX_SOCKET_CAPABILITY beside CMUX_SOCKET_PASSWORD and updates comments; it adds no Dispatch, Combine, completion-handler, or fire-and-forget Task pattern.
Cmux Swift @Concurrent	✅ Passed	The only Swift file change is embedded TypeScript in synchronous hookEnvironment; it adds environment forwarding and changes no async isolation, @concurrent, actor, or UI call site.
Cmux Swift Package Boundaries	✅ Passed	The diff only updates embedded Pi hook child-process environment forwarding in CLI/CMUXCLI+PiExtensionSourcePart1.swift; it adds no reusable or independently testable Swift domain logic.
Cmux Swiftpm Lockfiles	✅ Passed	The PR changes only CLI/CMUXCLI+PiExtensionSourcePart1.swift; it does not modify Package.swift, package references, .gitignore, workflows, dependencies, or any Package.resolved lockfile.
Cmux Swift Logging	✅ Passed	The diff adds only comments and CMUX_SOCKET_CAPABILITY environment forwarding; it adds no logging, diagnostics, or secret output.
Cmux User-Facing Error Privacy	✅ Passed	The diff only forwards CMUX_SOCKET_CAPABILITY and updates developer comments; it adds no user-facing error, alert, command output, API body, or recovery copy.
Cmux Full Internationalization	✅ Passed	The diff adds only CMUX_SOCKET_CAPABILITY environment handling and developer comments; no user-facing text, localization keys, catalogs, or locale-specific web content changed.
Cmux Swiftui State Layout	✅ Passed	The only diff adds CMUX_SOCKET_CAPABILITY forwarding and comments inside embedded TypeScript; it introduces no SwiftUI state, layout, row-store, or render-time mutation pattern.
Cmux Architecture Rethink	✅ Passed	The diff makes a small local credential-forwarding fix in the existing hookEnvironment path. It adds no timing, polling, locks, observers, duplicate wiring, or new state owner.
Cmux Swift Auxiliary Window Close Shortcuts	✅ Passed	The diff only forwards CMUX_SOCKET_CAPABILITY in embedded Pi hook code; it adds no NSWindow, NSPanel, controller, SwiftUI Window, identifier, or close-shortcut logic. The lint also passes.
Cmux Source Artifacts	✅ Passed	The only changed path is the tracked hand-written Swift source file CLI/CMUXCLI+PiExtensionSourcePart1.swift; no prohibited artifact directory or generated output appears in the diff.
Cmux No Test Or Debug Seam In Production Source	✅ Passed	The only changed file is CLI/CMUXCLI+PiExtensionSourcePart1.swift, outside /Sources/; its additions only forward CMUX_SOCKET_CAPABILITY and add comments, with no test/debug seam.
Cmux No Ambient Global State	✅ Passed	The diff only edits the existing embedded TypeScript in CMUXCLI.piExtensionSourcePart1; it adds no Swift free function, mutable global, static-helper namespace, or singleton.

✨ Finishing Touches

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[mrohan-sq]

🤖 Evidence chain from the diagnosis (cmux 0.64.22, macOS):

Symptom. automation.workspaceAutoNaming on, Pi Stop hooks acknowledged in ~/.cmuxterm/events.jsonl, autoNameRecentMessages cached in ~/.cmuxterm/pi-hook-sessions.json, workspace not user-owned — yet no rename, and no autoNameLastAttemptAt/autoNameInFlightAt markers were ever written. So the detached pass exited before beginAutoNaming.

Socket auth isolation. The pre-beginAutoNaming gate is the workspace.set_auto_title probe:

1. child process, capability kept:      {"enabled":true,...}
2. child process, capability removed:   {"enabled":true,...}      # ancestry auth still works
3. orphaned process, capability removed: ERROR: Access denied - only processes started inside cmux can connect
4. orphaned process, capability kept:    {"enabled":true,...}

spawnDetachedAgentAutoName orphans the pass via /bin/sh -c '... &' (case 3/4). The Pi extension's shouldPreserveEnvKey scrubber drops CMUX_SOCKET_CAPABILITY, so the real flow is case 3: the probe fails and the pass returns silently.

Fix verification. Replaying a Pi stop hook with the extension's exact scrubbed env plus the forwarded capability renamed the previously-unnamed workspace within ~5s and wrote the throttle markers. The same replay without the capability never renamed.

Scope. Only Pi is affected: the OMP and Campfire extensions pass { ...process.env } through unscrubbed, and Claude/Codex hooks inherit the terminal env directly. The fix forwards the capability only to cmux CLI children, mirroring the existing CMUX_SOCKET_PASSWORD handling, so it stays out of the generic allowlist.

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[teamleaderleo]

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