cmux

A Ghostty-based macOS terminal with vertical tabs and notifications for AI coding agents

Download cmux for macOS

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cmux screenshot

▶ Demo video · The Zen of cmux

## Features

Notification rings

Panes get a blue ring and tabs light up when coding agents need your attention
Notification rings

Notification panel

See all pending notifications in one place, jump to the most recent unread
Sidebar notification badge

In-app browser

Split a browser alongside your terminal with a scriptable API ported from agent-browser
Built-in browser

Vertical + horizontal tabs

Sidebar shows git branch, linked PR status/number, working directory, listening ports, and latest notification text. Split horizontally and vertically.
Vertical tabs and split panes

SSH

cmux ssh user@remote creates a workspace for a remote machine. Browser panes route through the remote network so localhost just works. Drag an image into a remote session to upload via scp.
cmux SSH

Claude Code Teams

cmux claude-teams runs Claude Code's teammate mode with one command. Teammates spawn as native splits with sidebar metadata and notifications. No tmux required.
Claude Code Teams
- **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.json`](https://cmux.com/docs/custom-commands) that launch from the command palette - **Scriptable** — 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/config` for themes, fonts, and colors - **GPU-accelerated** — Powered by libghostty for smooth rendering ## Install ### DMG (recommended) Download cmux for macOS Open the `.dmg` and drag cmux to your Applications folder. cmux auto-updates via Sparkle, so you only need to download once. ### Homebrew ```bash brew tap manaflow-ai/cmux brew install --cask cmux ``` To update later: ```bash 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](https://github.com/vercel-labs/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](https://cmux.com/docs/getting-started?utm_source=readme). ## 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 | 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 | ### 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](https://github.com/manaflow-ai/cmux/releases/download/nightly/cmux-nightly-macos.dmg) 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](https://github.com/manaflow-ai/cmux/issues) or in [#nightly-bugs on Discord](https://discord.gg/xsgFEVrWCZ). ## 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. tmux, vim, shells, and unsupported terminal apps reopen as normal terminals. Supported agent sessions can resume when hooks have saved a native session ID. Install hooks after installing the agent CLI so its binary is on `PATH`: ```bash cmux hooks setup cmux hooks setup codex cmux hooks setup --agent opencode ``` `cmux hooks setup` installs supported agents it can find and prints a summary for skipped agents. Supported resume integrations include Claude Code, Codex, Grok, OpenCode, Pi, Amp, Cursor CLI, Gemini, Rovo Dev, Copilot, CodeBuddy, Factory, and Qoder. Claude Code is handled by the cmux Claude wrapper when Claude integration is enabled in Settings. Advanced users and integrations can attach a custom resume command to the current terminal surface. This is useful for tools with their own durable state, such as tmux sessions or custom agent CLIs: ```bash cmux surface resume set --kind tmux --checkpoint work --shell "tmux attach -t work" cmux surface resume show --json cmux surface resume clear --checkpoint work ``` The binding stays attached to the cmux surface. Public CLI or socket-created bindings are stored for inspection and manual restore unless you approve a signed command prefix for automatic restore. Approved prefixes are also bound to the working directory and exact environment values, when present. Review or edit approvals in **Settings > Terminal > Resume Commands**. cmux only auto-runs resume bindings it marks trusted, such as live process-detected tmux bindings or user-approved prefixes. Sensitive environment keys such as tokens, passwords, secrets, and API keys are dropped before a resume binding is stored. To keep restored agent terminals idle instead of automatically running their resume commands, turn off **Settings > Terminal > Resume Agent Sessions on Reopen** or set this in `~/.config/cmux/cmux.json`: ```json { "terminal": { "autoResumeAgentSessions": false } } ``` This only disables automatic agent resume commands. cmux still restores the saved layout, working directories, scrollback, and browser history. If you need to reapply the last saved snapshot manually, use: - `File > Reopen Previous Session` - `⌘ ⇧ O` - `cmux restore-session` Under the hood, cmux writes a versioned snapshot under `~/Library/Application Support/cmux/` and agent hooks write session mappings under `~/.cmuxterm/`. On restore, cmux rebuilds the layout first, then runs the supported agent's native resume command when automatic agent resume is enabled. Read the full guide at . ## Star History Star History Chart ## Contributing Ways to get involved: - Follow us on X for updates [@manaflowai](https://x.com/manaflowai), [@lawrencecchen](https://x.com/lawrencecchen), and [@austinywang](https://x.com/austinywang) - Join the conversation on [Discord](https://discord.gg/xsgFEVrWCZ) - Create and participate in [GitHub issues](https://github.com/manaflow-ai/cmux/issues) and [discussions](https://github.com/manaflow-ai/cmux/discussions) - Let us know what you're building with cmux ## Community - [Discord](https://discord.gg/xsgFEVrWCZ) - [GitHub](https://github.com/manaflow-ai/cmux) - [X / Twitter](https://twitter.com/manaflowai) - [YouTube](https://www.youtube.com/channel/UCAa89_j-TWkrXfk9A3CbASw) - [LinkedIn](https://www.linkedin.com/company/manaflow-ai/) - [Reddit](https://www.reddit.com/r/cmux/) ## Founder's Edition cmux is free, open source, and always will be. If you'd like to support development and get early access to what's coming next: **[Get Founder's Edition](https://buy.stripe.com/3cI00j2Ld0it5OU33r5EY0q)** - **Prioritized feature requests/bug fixes** - **Early access: cmux AI that gives you context on every workspace, tab and panel** - **Early access: iOS app with terminals synced between desktop and phone** - **Early access: Cloud VMs** - **Early access: Voice mode** - **My personal iMessage/WhatsApp** ## License cmux is open source under [GPL-3.0-or-later](LICENSE). If your organization cannot comply with GPL, a commercial license is available. Contact [founders@manaflow.com](mailto:founders@manaflow.com) for details.