| name | cmux-settings |
| description | View and edit cmux settings in ~/.config/cmux/cmux.json. Use when the user wants to change cmux preferences (appearance, sidebar, notifications, automation, browser, shortcuts), set a value by JSON path, validate the file, open it in an editor, or look up which keys cmux recognizes. Triggers on '/cmux-settings', 'change cmux setting', 'set <something> in cmux', 'cmux config', 'cmux.json', or 'rebind a cmux shortcut'. |
cmux-settings
cmux reads user settings from ~/.config/cmux/cmux.json (JSONC). A file watcher applies changes on save, no restart. Legacy ~/.config/cmux/settings.json is read only as a fallback for keys absent from cmux.json.
Schema: https://raw.githubusercontent.com/manaflow-ai/cmux/main/web/data/cmux.schema.json. The authoritative path list is Sources/CmuxSettingsJSONPathSupport.swift; the installed skill carries a generated copy in references/all-keys.md. Settings sections are app, terminal, notifications, sidebar, sidebarAppearance, workspaceColors, automation, browser, shortcuts. Non-settings sections (actions, ui, commands, vault, rightSidebar) share the same file.
Helper script
Use the bundled helper for every read/write. It strips JSONC comments, writes atomically, and validates keys against the schema.
skills/cmux-settings/scripts/cmux-settings <subcommand>
~/.codex/skills/cmux-settings/scripts/cmux-settings <subcommand>
The rest of this doc assumes it is on $PATH as cmux-settings; from a checkout, export PATH="$PWD/skills/cmux-settings/scripts:$PATH".
| Command | What it does |
|---|
cmux-settings path | Print the config path. |
cmux-settings dump | Print the raw file (preserves comments). |
cmux-settings dump --no-comments | Print the parsed JSON. |
cmux-settings get <a.b.c> | Print value at dotted JSON path. |
cmux-settings set <a.b.c> <value> | Set value. <value> is parsed as JSON (true, 42, "text", […], {…}); unquoted plain words are stored as strings. |
cmux-settings unset <a.b.c> | Delete key, reverting to the in-app default. |
cmux-settings list-supported | List every settings JSON path the app recognizes. |
cmux-settings validate | Parse the file and flag unknown settings keys. |
cmux-settings open | Open cmux.json in $EDITOR, VS Code, Cursor, or TextEdit. |
--file <path> overrides the target file, useful for --file ~/.config/cmux/settings.json.
Workflow
- Look up the key when the user named a setting in plain English:
cmux-settings list-supported | rg -i 'sidebar.*terminal|terminal.*sidebar'
- Set it. JSON literals must be valid JSON.
cmux-settings set sidebarAppearance.matchTerminalBackground true
cmux-settings set app.appearance dark
cmux-settings set shortcuts.bindings.newTab '["ctrl+b","c"]'
cmux-settings set browser.hostsToOpenInEmbeddedBrowser '["localhost","*.internal.example"]'
- Read back and
cmux-settings validate.
- Tell the user it auto-reloaded, and that
cmux-settings unset <key> reverts it.
Quick reference
- Appearance:
app.appearance ("system" | "light" | "dark"), app.appIcon, app.menuBarOnly, app.minimalMode.
- Sidebar tint:
sidebarAppearance.matchTerminalBackground, .tintColor, .tintOpacity (0..1).
- Sidebar details:
sidebar.hideAllDetails, .showBranchDirectory, .showPullRequests, .showPorts, .showLog.
- Notifications:
notifications.dockBadge, .sound (enum including "none", "custom_file"), .customSoundFilePath, .hooks (array).
- Browser:
browser.defaultSearchEngine, .theme, .defaultZoomLevel, .openTerminalLinksInCmuxBrowser, .hostsToOpenInEmbeddedBrowser.
- Automation:
automation.socketControlMode (off | cmuxOnly | automation | password | allowAll), .portBase, .portRange.
- Shortcuts:
shortcuts.bindings.<actionId> = "cmd+b", ["ctrl+b","c"], null, or "" to unbind. Action ids in references/shortcut-actions.md.
Full list of settings, defaults, and descriptions: cmux-settings list-supported or references/all-keys.md.
Rules
- Only edit
cmux.json. Never settings.json unless the user explicitly asks; it is legacy and read only when a key is absent from cmux.json.
- Never tell the user to restart cmux. The file watcher reloads on save.
- Always
cmux-settings validate after a bulk edit. Unknown keys mean the user pasted a key the app does not consume.
- Do not blindly overwrite
actions, ui, commands, vault, or rightSidebar; they share the file and hold hand-tuned non-settings config.
- Shortcut action ids must match the schema enum. Look them up before binding.
- Colors are
#RRGGBB; opacities are 0..1.
- Translate app-level phrasing ("Settings > Notifications > Dock badge") to the JSON path first;
web/app/[locale]/(landing)/docs/configuration/page.tsx mirrors the schema 1:1.
