git:20260906.6a656fc to git:20260925.cb72780

- description: 'Control the cmux macOS terminal app (CLI + socket API) — cmux workspaces, panes, surfaces, browser automation, notifications, settings, hooks. MUST be read before running any `cmux` command. Trigger ONLY when the user explicitly says "cmux" — a cmux pane, cmux workspace, cmux surface, or an agent running in cmux. Do NOT trigger on generic mentions of "workspace", "pane", "the other agent", or "delegate" when cmux is not named — workspaces in tmux, Ghostty, herdr, VS Code, etc. are NOT cmux. macOS only (14.0+).'

- cmux is a native macOS terminal app for running multiple AI coding agents in parallel. It exposes a CLI (`cmux`) and a Unix-socket JSON-RPC API (`/tmp/cmux.sock`) for full topology and browser control.

-

- ## Core Concepts

-

- - **Window** — top-level macOS cmux window

- - **Workspace** — sidebar tab within a window (one git branch / project context)

- - **Pane** — split region inside a workspace

- - **Surface** — tab inside a pane (terminal or browser)

-

- Handles default to short refs (`workspace:2`, `pane:1`, `surface:7`); UUIDs accepted as input. Add `--id-format uuids|both` for UUID output.

-

- ### Ref syntax — get this right or fail silently

-

- - **Always use PREFIXED refs** (`pane:38`, `surface:46`). A **bare number is treated as an INDEX, not an ID** — `--surface 46` means "the surface at index 46" (usually nonexistent → silent failure), NOT `surface:46`.

- - **`read-screen` and `capture-pane` have NO `--pane` flag** — they target `--workspace` or `--surface` only. Passing `--pane` errors, and a bare/missing target falls back to your OWN surface (you'll read your own footer and draw wrong conclusions). To read a pane: resolve it to a surface FIRST with `cmux list-pane-surfaces --pane pane:N`, then `cmux read-screen --surface surface:N`.

- - **Never append `2>/dev/null` to cmux commands.** Errors go to stderr with exit code 1; suppressing them blinds you to your own ref/flag mistakes (the #1 cause of "(no output)").

-

- ## Detect cmux in a Shell

-

- ```bash

- [ -S "${CMUX_SOCKET_PATH:-/tmp/cmux.sock}" ] || exit 0 # bail if not in cmux

- [ -n "${CMUX_WORKSPACE_ID:-}" ] && echo "inside cmux surface"

- ```

-

- Injected env vars in every cmux-spawned terminal: `CMUX_WORKSPACE_ID`, `CMUX_SURFACE_ID`, `CMUX_SOCKET_PATH`, `CMUX_PORT`. **Always anchor automation to `CMUX_WORKSPACE_ID`** — the visually focused workspace may not be the agent's caller workspace.

-

- ## Fast Start — Topology

-

- ```bash

- cmux identify --json # who am I (window/workspace/pane/surface)

- cmux tree # full hierarchy

- cmux list-workspaces --json

- cmux list-panes --workspace "$CMUX_WORKSPACE_ID"

- cmux list-surfaces --workspace "$CMUX_WORKSPACE_ID"

-

- cmux new-workspace --name "feature-x" --cwd /path/to/repo

- cmux new-pane --workspace "$CMUX_WORKSPACE_ID" --type terminal --direction right --focus false

- cmux new-pane --workspace "$CMUX_WORKSPACE_ID" --type browser --direction right --url http://localhost:3000

- cmux move-surface --surface surface:7 --pane pane:2 --focus false

- cmux split-off --surface surface:7 right

- cmux reorder-surface --surface surface:7 --before surface:3

- cmux close-surface --surface surface:7

- ```

-

- ## Polling Panes for Output — Keep Sleeps Short

-

- When polling any cmux pane — a Pi Agent, an SSH login, a running command — use **short `sleep` intervals (1–3s)**. Pi is fast and minimal, and the user runs it on Opus 4.8 Fast via OpenRouter, which streams tokens extremely quickly. Do NOT use `sleep 10`+ unless genuinely needed (a big build/refactor) — `sleep 1`–`sleep 3` is almost always enough.

-

- If the screen is not ready yet, just `read-screen` again instead of padding the sleep. A second 1s check costs less than one 7s guess, and long fixed sleeps waste the user's time on every step.

-

- After every agent check, send the user a one-line status update: what the agent is doing and whether it is on track. Keep it extremely concise.

-

- Claude Code cmux note: after Claude finishes, it may prefill a predicted next user message; that draft is Claude, not the user speaking.

-

- ## Send Input

-

- **Command names:** there is NO `send-surface` / `send-key-surface`. Target a specific surface with the `--surface` flag on `send` / `send-key` (same commands as the focused terminal). `send-panel` / `send-key-panel` exist ONLY for panels (`--panel`), not surfaces.

-

- ```bash

- cmux send "echo hi\n" # focused terminal

- cmux send-key "ctrl+c" # enter|tab|esc|backspace|arrows|ctrl+x|shift+tab

- cmux send --surface surface:7 "npm run build" # specific surface (NOT send-surface)

- cmux send-key --surface surface:7 enter # specific surface (NOT send-key-surface)

- ```

-

- ## Notifications & Sidebar Metadata

-

- ```bash

- cmux notify --title "Done" --body "tests passed"

- cmux set-status build "compiling" --icon hammer --color "#ff9500"

- cmux set-progress 0.5 --label "Building..."

- cmux log --level success "All 42 tests passed" # info|progress|success|warning|error

- cmux trigger-flash --workspace "$CMUX_WORKSPACE_ID" # blue-ring attention cue

- cmux sidebar-state --json # dump all sidebar metadata

- ```

-

- ## Browser Automation (WKWebView)

-

- Workflow: open → wait → snapshot → act → re-snapshot.

-

- ```bash

- S=$(cmux --json browser open https://example.com | jq -r .result.surface_ref)

- cmux browser "$S" wait --load-state complete --timeout-ms 15000

- cmux browser "$S" snapshot --interactive # returns elements as e1, e2, ...

- cmux browser "$S" fill e1 "<email-address>"

- cmux browser "$S" click e2 --snapshot-after

-

- # Navigation / inspection

- cmux browser "$S" goto URL | back | forward | reload

- cmux browser "$S" get url | get title | get text body | get value "#email" | get count ".row"

- cmux browser "$S" eval 'return document.title'

-

- # Waits

- cmux browser "$S" wait --selector "#ready" --timeout-ms 10000

- cmux browser "$S" wait --url-contains "/dashboard" --timeout-ms 10000

-

- # Session

- cmux browser "$S" cookies get | cookies set --name foo --value bar

- cmux browser "$S" state save /tmp/auth.json | state load /tmp/auth.json

-

- # Diagnostics

- cmux browser "$S" console list | errors list | screenshot

- ```

-

- **Not supported by WKWebView** (return `not_supported`): viewport emulation, geolocation/offline emulation, trace recording, network route interception, raw input injection.

-

- ## Markdown Viewer

-

- ```bash

- cmux markdown open plan.md --direction right # live-watching renderer

- cmux open file.pdf # auto-routes to right viewer

- ```

-

- `cmux markdown open` flags: `--workspace`, `--surface`, `--window`, `--direction <right|down|left|up>`, `--focus <true|false>`. There is **NO `--pane` flag** — passing it errors. To target a pane, pass `--surface <existing-md-surface-in-that-pane>`.

-

- ### Reuse the existing right markdown pane (don't spawn strays)

-

- Default behavior of `markdown open` is to **create a new pane** every time, even with `--direction right`. To keep all docs as tabs in ONE right pane, follow this exactly:

- ```bash

- # 1. Find the right pane and its surfaces (anchor to THIS workspace)

- cmux list-panes --workspace "$CMUX_WORKSPACE_ID"

- cmux list-pane-surfaces --pane pane:10 # the right/helper pane

- # 2. Open targeting an existing markdown surface IN that pane (reuses pane, adds tab)

- cmux markdown open /abs/path/file.md --surface surface:12 --focus false

- # 3. If it STILL spawned a new pane (it can), move the new surface in + verify

- cmux move-surface --surface surface:NEW --pane pane:10 --focus false

- cmux list-panes --workspace "$CMUX_WORKSPACE_ID" # confirm stray pane is gone

- ```

- ### Swapping the file in the single right pane (close-FIRST, then open)

- To replace the doc shown in your one right markdown pane, the ONLY reliable order is **close the previous surface FIRST, then `markdown open` the new file fresh** — never move an existing viewer, never open-then-close.

- # 1. close the previous right markdown surface (right side goes empty)

- cmux close-surface --surface surface:PREV

- # 2. THEN open the new file fresh

- cmux markdown open /abs/path/new.md --direction right --focus false

- ORDER MATTERS: close-previous BEFORE open-new. Opening first then closing the old one, or `move-surface`-ing an existing viewer, leaves the right pane BLANK.

-

- ### Hard-won lessons (avoid the trial-and-error)

-

- - **Surface refs are global, not per-workspace.** A ref like `surface:126` from an earlier `markdown open` may live in a different window/workspace. Always re-list (`list-panes` / `list-pane-surfaces`) before reusing a ref — never assume a ref from a previous turn is still in the right pane.

- - **`move-surface`-ing a markdown viewer often leaves it BLANK.** The moved surface keeps `type=markdown` and `surface-health` looks fine, but renders nothing. Fix: `close-surface` it and `cmux markdown open <path>` fresh, then move the *fresh* surface if needed. Don't waste time on `refresh-surfaces` — it usually won't fix a moved-then-blank viewer.

- - **You cannot screenshot or `read-screen` a markdown surface** (`Surface is not a terminal` / browser screenshot is WKWebView-only). To verify a markdown viewer rendered, ask the user or open the file in a browser surface instead. Don't burn turns trying to capture it.

- - **`cmux list-surfaces` does not exist.** Use `cmux list-pane-surfaces [--pane ...]`.

- ## Settings & Config

- cmux docs settings # prints paths, schema URL, reload cmd — read BEFORE editing

- cmux settings path # path to cmux.json

- cmux settings cmux-json # open in editor

- cmux reload-config # hot-reload cmux.json + ~/.config/ghostty/config (Cmd+Shift+,)

- ```

-

- Locations:

- - cmux settings: `~/.config/cmux/cmux.json` (canonical). Project-local override: `.cmux/cmux.json` or `./cmux.json`.

- - Terminal rendering (font, cursor, theme, scrollback, opacity, blur): `~/.config/ghostty/config` — NOT cmux.json.

-

- Before editing `cmux.json`, copy it to a timestamped `.bak` next to it so the user can revert. Schema: `https://raw.githubusercontent.com/manaflow-ai/cmux/main/web/data/cmux.schema.json`.

-

- ### Sidebar text blurbs under workspaces

-

- The paragraph under each sidebar workspace title has TWO sources, each with its own toggle in `cmux.json` (also in Settings > Sidebar):

-

- ```jsonc

- "sidebar": {

- "showWorkspaceDescription": false, // custom/AI workspace descriptions

- "showNotificationMessage": false // latest agent message preview (the "Repo scanned…" style blurb)

- }

- The user keeps BOTH off (set 18-07-2026) — don't re-enable. `sidebar.hideAllDetails: true` hides the entire detail block (status, branch, cwd) if ever needed.

-

- ## Agent Hooks & Install

-

- ```bash

- brew tap manaflow-ai/cmux && brew install --cask cmux

- sudo ln -sf /Applications/cmux.app/Contents/Resources/bin/cmux /usr/local/bin/cmux

- cmux hooks setup # all detected agents

- cmux hooks setup codex|grok|antigravity|opencode # specific agent

- npx skills add manaflow-ai/cmux -g -y # install cmux skills for agents

- ```

- Native session-resume supported for: Claude Code, Codex, Grok, OpenCode, Pi, Amp, Cursor CLI, Gemini, Antigravity, Rovo Dev, Hermes, Copilot, CodeBuddy, Factory, Qoder.

- ## Socket API (advanced)

- `/tmp/cmux.sock` — Unix socket, JSON-RPC v2. Use for tight loops where subprocess spawn cost matters; otherwise prefer the CLI.

- echo '{"id":"1","method":"workspace.list","params":{}}' | nc -U /tmp/cmux.sock

- Method prefixes: `system.*`, `window.*`, `workspace.*`, `pane.*`, `surface.*`, `notification.*`, `browser.*`. Full list and Python client example in `references/socket-api.md`.

-

- Access modes: `cmuxOnly` (default — only cmux-spawned processes), `automation` (any local process), `password`, `allowAll` (unsafe). If you hit `Failed to connect to socket`, you're likely an external process under `cmuxOnly` — switch mode in Settings > Automation or run from inside a cmux terminal.

-

- ## Critical Rules — Non-Disruptive Automation

-

- These rules come from the `cmux-workspace` skill and prevent agents from yanking the user's focus:

-

- 1. **Anchor to `CMUX_WORKSPACE_ID`.** Never assume the visually focused workspace is the target.

- 2. **Never call focus-changing verbs speculatively.** `select-workspace`, `focus-pane`, `focus-panel`, `focus-surface` only on explicit user request. Pass `--focus false` whenever available.

- 3. **Build layout additively in one call.** `cmux new-pane --type … --focus false` beats create-then-move-then-focus chains.

- 4. **Right-side helper pane pattern.** Reuse an existing non-caller helper pane if present; otherwise create exactly one right-side pane.

- 5. **Never send input to surfaces you don't own.** Only target surfaces in the caller's workspace unless the user explicitly asks for cross-workspace routing.

- 6. **Check surface health before routing input** when UI state may be stale: `cmux surface-health`.

-

- ## Common Pitfalls

- - **Pi/Pi-like socket connection failures from external processes** → default `cmuxOnly` mode; either run inside a cmux terminal or change socket mode.

- - **macOS only.** No Linux/Windows port.

- - **WKWebView ≠ CDP.** Don't expect Playwright-equivalent network mocking or viewport emulation.

- - **Resume strips sensitive env vars.** Re-inject tokens at resume time if the agent needs them.

- - **Skills snapshot at app start.** Edits to skill files require a restart of the consuming agent.

- - **Legacy v1 socket payloads (`{"command":...}`) rejected.** Use v2 JSON-RPC only.

- - **Don't `cat ~/.cmuxterm/*-hook-sessions.json`** expecting secrets — they're scrubbed. Look there for session/surface mappings only.

- ## Reference: Full CLI Help

- For any command, `cmux <cmd> --help` is authoritative. Use `cmux capabilities --json` to enumerate available socket methods in the current build.

- ## Keyboard Shortcuts (most-used)

- Workspaces: ⌘N new, ⌘1–8 jump, ⌃⌘[ / ⌃⌘] prev/next, ⌘⇧W close, ⌘B sidebar.

- Surfaces: ⌘T new, ⌘⇧[ / ⌘⇧] prev/next, ⌘W close, ⌃1–8 jump.

- Splits: ⌘D right, ⌘⇧D down, ⌥⌘D browser right, ⌥⌘←→↑↓ focus directional, ⌘⇧↵ zoom.

- Browser: ⌘⇧L open, ⌘L address bar, ⌘[/⌘] back/forward, ⌥⌘I devtools.

- App: ⌘, settings, ⌘⇧, reload-config, ⌘⇧P palette, ⌘⇧O restore session, ⌃⌥⌘. system-wide show/hide.