cmux

Overview

cmux is a free and open source native macOS terminal built on Ghostty for multitasking, organization, and programmability. It is designed for developers running coding agents, with vertical tabs, notification rings, split panes, an in-app browser, and a CLI.

Key Features

• Vertical tabs show git branch, working directory, listening ports, and latest notification text.
• Notification rings and sidebar badges alert when coding agents need attention.
• Split panes support horizontal and vertical splits within each tab.
• The in-app browser can be split alongside the terminal and controlled through a scriptable API.
• A CLI and Unix socket API enable automation, scripting, and workspace control.
• The native Swift and AppKit app uses libghostty for GPU-accelerated rendering.

Use Cases

• Running multiple coding agents in parallel and seeing which pane needs attention.
• Orchestrating subagents or teammates as native panes and splits instead of hidden background processes.
• Verifying web changes with the in-app browser while agents work in the terminal.
• Working with remote machines by opening workspaces over SSH and attaching to remote tmux sessions.

Getting Started

• Download the macOS DMG, open it, and drag cmux to the Applications folder; cmux auto-updates via Sparkle.
• Alternatively, install with Homebrew by running brew tap manaflow-ai/cmux and brew install --cask cmux.
• On first launch, macOS may ask you to confirm opening an app from an identified developer; click Open to proceed.

Deployment & Requirements

• Requires macOS to run the native cmux terminal app.
• Available platform builds are listed in the Download menu; platforms not yet released have a waitlist.

Before You Adopt

• License: Other. Review its terms before using, modifying, or distributing the project.
• The iOS companion app is in beta.
• The iOS companion is distributed through TestFlight as cmux BETA.