Socket command threading and focus policy for cmux CLI/socket work. Use when adding or changing socket commands, CLI commands, telemetry commands, focus/select/open/close/send-key behavior, or automation that could steal app focus.
Installation
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Socket command threading and focus policy for cmux CLI/socket work. Use when adding or changing socket commands, CLI commands, telemetry commands, focus/select/open/close/send-key behavior, or automation that could steal app focus.
cmux Socket Policy
Threading policy
Do not use DispatchQueue.main.sync for high-frequency socket telemetry commands such as report_*, ports_kick, status/progress updates, or log metadata updates.
For telemetry hot paths, parse and validate arguments off-main.
Dedupe and coalesce off-main first.
Schedule minimal UI/model mutation with DispatchQueue.main.async only when needed.
Commands that directly manipulate AppKit/Ghostty UI state are allowed to run on the main actor.
If adding a new socket command, default to off-main handling and require an explicit reason in code comments when main-thread execution is necessary.
Focus policy
Socket/CLI commands must not steal macOS app focus.
Do not activate the app or raise windows unless the command has explicit focus intent.
Only explicit focus-intent commands may mutate in-app focus/selection.
Explicit focus-intent commands include window.focus, workspace.select/next/previous/last, surface.focus, pane.focus/last, browser focus commands, and v1 focus equivalents.
All non-focus commands should preserve the current user focus context while still applying data/model changes.
Detailed reference
Read references/threading-and-focus.md when adding a command, changing command execution context, or deciding whether focus changes are allowed.