cmux
Open source Ghostty-based macOS terminal with vertical tabs and notifications for AI coding agents. Built for multitasking, organization, and programmability.
Install / Use
npx skills add manaflow-ai/cmuxInstalls into whichever agent you are using.
CLAUDE.md
Claude Code project instructions
Quality Score
Category
CommunicationSupported Platforms
Tags
Our assessment of cmux
cmux scores 99/100 on our quality scale, 5th of 396 Communication skills we index (top 2%).
Its CLAUDE.md is 24 KB long, well organised into 44 sections with 7 code examples: a thorough specification that gives an agent plenty to work with.
With 28,710 GitHub stars, it is one of the more widely adopted skills in the catalogue.
Maintenance, license and trust
- The repository was last updated today, so cmux is actively maintained.
- Our last check on 2026-10-17 found the source still online.
- No license is declared. By default that means all rights are reserved: you can read it, but reusing or redistributing it is not clearly permitted. Ask the author before building on it commercially.
- Its trust signals score 88/100, with 1 caution from licensing, adoption, age or documentation. These come from repository metadata, not a code audit — read the skill file before letting an agent act on it.
Safety scan
No issues foundOur scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands. An AI review of the same text found nothing harmful.
AI review by kimi-k2.7-code on 2026-09-24. Automated pattern scan on 2026-09-24. It catches known dangerous patterns, not every risk — read a skill before letting an agent act on it.
cmux compared with similar skills
All 4 of these similar skills score higher than cmux; compare them before choosing.
| Skill | Score | Stars | Updated | Format |
|---|---|---|---|---|
| cmux (this skill)by manaflow-ai | 99 | 28.7k | today | CLAUDE.md |
| claude-memby thedotmack | 100 | 113.5k | today | CLAUDE.md |
| taste-skillby Leonxlnx | 100 | 110.6k | today | CLAUDE.md |
| Agent-Reachby Panniantong | 100 | 109.2k | today | CLAUDE.md |
| Understand-Anythingby Egonex-AI | 100 | 90.9k | 10d ago | CLAUDE.md |
Frequently asked questions
- How do I install cmux?
- Run
npx skills add manaflow-ai/cmux. The install tabs above show the steps for each supported agent. - Which AI agents does cmux work with?
- It is written for Claude Code, Gemini CLI and OpenAI Codex, as a CLAUDE.md file. Other agents that read the same format can often use it too.
- Is cmux safe to use?
- Our scan of the whole file found no instruction hijacking, hidden characters, credential access, data exfiltration or destructive commands. An AI review of the same text found nothing harmful. It declares no license and scores 88/100 on trust signals. Skills are instructions an agent will follow, so read the file before installing it and do not approve commands you do not understand.
- Is cmux still maintained?
- The repository was last updated today, so cmux is actively maintained.
Skill content
View source on GitHubFeatures
<table> <tr> <td width="40%" valign="middle"> <h3>Notification rings</h3> Panes get a blue ring and tabs light up when coding agents need your attention </td> <td width="60%"> <img src="./docs/assets/notification-rings.png" alt="Notification rings" width="100%" /> </td> </tr> <tr> <td width="40%" valign="middle"> <h3>Notification panel</h3> See all pending notifications in one place, jump to the most recent unread </td> <td width="60%"> <img src="./docs/assets/sidebar-notification-badge.png" alt="Sidebar notification badge" width="100%" /> </td> </tr> <tr> <td width="40%" valign="middle"> <h3>In-app browser</h3> Split a browser alongside your terminal with a scriptable API ported from <a href="https://github.com/vercel-labs/agent-browser">agent-browser</a> </td> <td width="60%"> <img src="./docs/assets/built-in-browser.png" alt="Built-in browser" width="100%" /> </td> </tr> <tr> <td width="40%" valign="middle"> <h3>Vertical + horizontal tabs</h3> Sidebar shows git branch, linked PR status/number, working directory, listening ports, and latest notification text. Split horizontally and vertically. </td> <td width="60%"> <img src="./docs/assets/vertical-horizontal-tabs-and-splits.png" alt="Vertical tabs and split panes" width="100%" /> </td> </tr> <tr> <td width="40%" valign="middle"> <h3>SSH</h3> <code>cmux ssh user@remote</code> creates a workspace for a remote machine. Pass <code>--command 'omp "investigate auth"'</code> to run an initial command once in its first remote terminal. Browser panes route through the remote network so localhost just works. Drag an image into a remote session to upload via scp. </td> <td width="60%"> <img src="./docs/assets/ssh.png" alt="cmux SSH" width="100%" /> </td> </tr> <tr> <td width="40%" valign="middle"> <h3>Claude Code Teams</h3> <code>cmux claude-teams</code> runs Claude Code's teammate mode with one command. Teammates spawn as native splits with sidebar metadata and notifications. No tmux required. </td> <td width="60%"> <img src="./docs/assets/claude-code-teams.png" alt="Claude Code Teams" width="100%" /> </td> </tr> </table>- Browser import — Import cookies, history, and sessions from Chrome, Firefox, Arc, and 20+ browsers so browser panes start authenticated
- Custom commands — Define project-specific actions in
cmux.jsonthat launch from the command palette - Programmable — CLI and socket API to create workspaces, split panes, send keystrokes, and automate the browser
- Native macOS app — Built with Swift and AppKit, not Electron. Fast startup, low memory.
- Ghostty compatible — Reads your existing
~/.config/ghostty/configfor themes, fonts, and colors - GPU-accelerated — Powered by libghostty for smooth rendering
- Keyboard shortcuts — Extensive shortcuts for workspaces, splits, browser, and more
- Open source — Free and GPL-licensed
Install
DMG (recommended)
<a href="https://github.com/manaflow-ai/cmux/releases/latest/download/cmux-macos.dmg"> <img src="./docs/assets/macos-badge.png" alt="Download cmux for macOS" width="180" /> </a>Open the .dmg and drag cmux to your Applications folder. cmux auto-updates via Sparkle, so you only need to download once.
Homebrew
brew tap manaflow-ai/cmux
brew install --cask cmux
To update later:
brew upgrade --cask cmux
On first launch, macOS may ask you to confirm opening an app from an identified developer. Click Open to proceed.
Why cmux?
I run a lot of Claude Code and Codex sessions in parallel. I was using Ghostty with a bunch of split panes, and relying on native macOS notifications to know when an agent needed me. But Claude Code's notification body is always just "Claude is waiting for your input" with no context, and with enough tabs open I couldn't even read the titles anymore.
I tried a few coding orchestrators but most of them were Electron/Tauri apps and the performance bugged me. I also just prefer the terminal since GUI orchestrators lock you into their workflow. So I built cmux as a native macOS app in Swift/AppKit. It uses libghostty for terminal rendering and reads your existing Ghostty config for themes, fonts, and colors.
The main additions are the sidebar and notification system. The sidebar has vertical tabs that show git branch, linked PR status/number, working directory, listening ports, and the latest notification text for each workspace. The notification system picks up terminal sequences (OSC 9/99/777) and has a CLI (cmux notify) you can wire into agent hooks for Claude Code, OpenCode, etc. When an agent is waiting, its pane gets a blue ring and the tab lights up in the sidebar, so I can tell which one needs me across splits and tabs. Cmd+Shift+U jumps to the most recent unread.
The in-app browser has a scriptable API ported from agent-browser. Agents can snapshot the accessibility tree, get element refs, click, fill forms, and evaluate JS. You can split a browser pane next to your terminal and have Claude Code interact with your dev server directly.
Everything is scriptable through the CLI and socket API — create workspaces/tabs, split panes, send keystrokes, open URLs in the browser.
The Zen of cmux
cmux is not prescriptive about how developers hold their tools. It's a terminal and browser with a CLI, and the rest is up to you.
cmux is a primitive, not a solution. It gives you a terminal, a browser, notifications, workspaces, splits, tabs, and a CLI to control all of it. cmux doesn't force you into an opinionated way to use coding agents. What you build with the primitives is yours.
The best developers have always built their own tools. Nobody has figured out the best way to work with agents yet, and the teams building closed products definitely haven't either. The developers closest to their own codebases will figure it out first.
Give a million developers composable primitives and they'll collectively find the most efficient workflows faster than any product team could design top-down.
Documentation
For more info on how to configure cmux, head over to our docs.
Keyboard Shortcuts
Workspaces
| Shortcut | Action | |----------|--------| | ⌘ N | New workspace | | ⌘ 1–8 | Jump to workspace 1–8 | | ⌘ 9 | Jump to last workspace | | ⌃ ⌘ ] | Next workspace | | ⌃ ⌘ [ | Previous workspace | | ⌘ ⇧ W | Close workspace | | ⌘ ⇧ R | Rename workspace | | ⌥ ⌘ E | Edit workspace description | | ⌘ B | Toggle sidebar | | ⌥ ⌘ B | Toggle right sidebar | | ⌘ ⇧ E | Toggle right sidebar focus |
Surfaces
| Shortcut | Action | |----------|--------| | ⌘ T | New surface | | ⌘ ⇧ ] | Next surface | | ⌘ ⇧ [ | Previous surface | | ⌃ Tab | Next surface | | ⌃ ⇧ Tab | Previous surface | | ⌃ 1–8 | Jump to surface 1–8 | | ⌃ 9 | Jump to last surface | | ⌘ W | Close surface |
Split Panes
| Shortcut | Action | |----------|--------| | ⌘ D | Split right | | ⌘ ⇧ D | Split down | | ⌥ ⌘ ← → ↑ ↓ | Focus pane directionally | | ⌃ ⇧ H J K L | Resize pane left/down/up/right | | ⌘ ⇧ H | Flash focused panel |
Browser
Browser developer-tool shortcuts follow Safari defaults and are customizable in Settings → Keyboard Shortcuts.
Command palette navigation shortcuts, including ⌃ P, are also customizable and can be cleared so the keypress reaches the active terminal.
| Shortcut | Action | |----------|--------| | ⌘ ⇧ L | Open browser in split | | ⌘ L | Focus address bar | | ⌘ [ | Back | | ⌘ ] | Forward | | ⌘ R | Reload page | | ⌥ ⌘ I | Toggle Developer Tools (Safari default) | | ⌥ ⌘ C | Show JavaScript Console (Safari default) |
Notifications
| Shortcut | Action |
|----------|--------|
| ⌘ I | Show notifications panel |
| ⌘ ⇧ U | Jump to latest unread |
| ⌥ ⌘ U | Toggle current item unread state |
| ⌃ ⌘ U | Mark current item as oldest unread and jump to next latest unread |
| — | Mark all notifications read (unbound by default; configure in Settings or cmux.json) |
| — | Clear all notifications (unbound by default; configure in Settings or cmux.json) |
Find
| Shortcut | Action | |----------|--------| | ⌘ F | Find | | ⌘ ⇧ F | Find in directory | | ⌘ G / ⌥ ⌘ G | Find next / previous | | ⌥ ⌘ ⇧ F | Hide find bar | | ⌘ E | Use selection for find |
Terminal
| Shortcut | Action | |----------|--------| | ⌘ K | Clear scrollback | | ⌘ C | Copy (with selection) | | ⌘ V | Paste | | ⌘ + / ⌘ - | Increase / decrease font size | | ⌘ 0 | Reset font size |
Window
| Shortcut | Action | |----------|--------| | ⌘ ⇧ N | New window | | ⌘ ⇧ O | Reopen previous session | | ⌘ , | Settings | | ⌘ ⇧ , | Reload configuration | | ⌘ Q | Quit |
Nightly Builds
Download cmux NIGHTLY (universal; updates then switch to your Mac's architecture automatically)
cmux NIGHTLY is a separate app with its own bundle ID, so it runs alongside the stable version. Built automatically from the latest main commit and auto-updates via its own Sparkle feed.
Report nightly bugs on GitHub Issues or in #nightly-bugs on Discord.
Session restore
Quitting cmux saves the current session. On relaunch, cmux restores app-owned state:
- Window/workspace/pane layout
- Working directories
- Terminal scrollback (best effort)
- Browser URL and navigation history
cmux does not checkpoint arbitrary live process state. Ordinary terminals,
tmux, vim, shells, and unsupported terminal apps reopen as normal terminals.
For live detach/reattach across cmux quit, crashes, and updates, opt in to the
local tmux owner with cmux local-tmux; see [docs/local-tmux.md](docs/local-tmux.m
Truncated for display — read the full file on GitHub.
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Trust signals
From repository metadata: license, adoption, age and documentation. Not a code audit — see the Safety scan above for what the skill file itself contains.