Cmux
Officially recommendedA Ghostty-based macOS terminal with vertical tabs and notifications for AI coding agents.
Download Cmux
macOS package (.dmg), architecture unlisted — verify before installing
Other downloads (3)
Getting a "can't verify the developer" warning?
If you see a warning on first launch, go to System Settings > Privacy & Security and click "Open Anyway". Open source software usually isn't signed with an Apple developer certificate, which is normal.
Clicking "Download" takes you to a source confirmation page first; the download starts after confirmation.
About Cmux
Open source Ghostty-based macOS terminal with vertical tabs and notifications for AI coding agents. Built for multitasking, organization, and programmability.
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Who it's for
- Developers who run multiple AI coding agents simultaneously and need clear status notifications
- Users who prefer native macOS apps and want to avoid the high resource usage of Electron/Tauri
- Users who already have a Ghostty configuration and want to reuse their themes and fonts directly in a new terminal
- Programmers who manage remote machines via SSH and prefer to operate from a unified local interface
- Advanced users who want to customize their terminal workflow via CLI/API
Who it's not for
- Users not on macOS (currently macOS-only)
- Users who prefer text-based multiplexers like tmux and don't need a GUI
- Teams that need a consistent cross-platform terminal experience (no native Windows/Linux support yet)
Install guide
macOS Users
- Download cmux-macos.dmg (recommended on this site).
- Double-click the
.dmgfile and drag thecmuxicon into theApplicationsfolder. - If you see the "cannot be opened because the developer cannot be verified" prompt on first launch, go to System Settings → Privacy & Security, click Open Anyway in the Security section, or right-click the app and select Open.
- Cmux automatically updates via Sparkle, so you don't need to manually download new versions afterwards.
Install via Homebrew (Optional)
brew tap manaflow-ai/cmux
brew install --cask cmux
# Update
brew upgrade --cask cmuxAbout the Remote Component
The cmuxd-remote-* files in the release assets are used for SSH remote functionality. Only if you need to run agents on remote machines, choose the appropriate architecture on the remote host:
cmuxd-remote-darwin-amd64/cmuxd-remote-darwin-arm64: remote macOS hostscmuxd-remote-linux-amd64/cmuxd-remote-linux-arm64: remote Linux hosts
appcast.xml is for automatic updates and requires no manual action.
FAQ
Is Cmux free?
Yes, Cmux is completely free and open-source under GPL-3.0-or-later. The source code is available on GitHub.
What operating systems does Cmux support?
Currently only macOS. It is a native app written in Swift and AppKit. Windows and Linux are not supported yet (the remote component has Linux versions, but the main app is macOS-only).
How do I update Cmux?
Cmux installed from the DMG has built-in Sparkle automatic updates and will prompt you when a new version is available. If installed via Homebrew, just run `brew upgrade --cask cmux`.
What should I do if I see a "developer cannot be verified" prompt on first launch?
On macOS, the first launch may show "cannot be opened because the developer cannot be verified." Go to "System Settings → Privacy & Security," click "Open Anyway" in the Security section, or right-click the app and select "Open."
What is the relationship between Cmux and Ghostty?
Cmux is not a fork of Ghostty. Instead, it uses libghostty as its terminal rendering engine, similar to how WebKit renders web pages. Cmux reads your Ghostty configuration file to apply themes, fonts, and colors.