Getting Started
cmux is a lightweight, native macOS terminal built on Ghostty for managing multiple AI coding agents. It features vertical tabs, a notification panel, and a socket-based control API.
Install
The fastest way to get started is downloading the DMG directly. Follow the four steps below — each one takes a few seconds.
Download the DMG
Click "Download for Mac" at the top of the page to get the latest .dmg.
Drag to Applications
Open the .dmg and drag the cmux icon into your Applications folder.
"cmux" is an app downloaded from the Internet. Are you sure you want to open it?
Confirm the developer
On first launch, macOS asks you to confirm. Click "Open" to proceed.
Launch and verify
Open cmux — you'll see a vertical tab sidebar with one workspace ready to go.
Homebrew
Prefer the command line? Install cmux via Homebrew instead:
$brew install --cask cmux
To update later:
Verify installation
Open cmux and you should see:
- A terminal window with a vertical tab sidebar on the left
- One initial workspace already open
- The Ghostty-powered terminal ready for input
CLI setup
cmux includes a command-line tool for automation. Inside cmux terminals it works automatically. To use the CLI from outside cmux, create a symlink:
Then you can run commands like:
$cmux notify --title "Build Complete" --body "Your build finished"
Auto-updates
cmux checks for updates automatically via Sparkle. When an update is available you'll see an update pill in the titlebar. You can also check manually via cmux → Check for Updates in the menu bar.
Session restore
cmux restores layout and metadata after relaunch. Supported agent sessions can also resume when hooks have captured a native resume token.
cmux does not checkpoint arbitrary live process state. Unsupported terminal apps such as tmux, vim, and ordinary shells reopen as normal terminals.
See the session restore guide for agent hook setup and the supported resume matrix.