cmux is an open-source macOS terminal designed for running AI coding agents. Built on the fast Ghostty terminal engine, it adds vertical tabs, smart notifications and a programmable workspace layout, so you can keep several agents working side by side and always know which one needs your attention.
cmux has gathered more than 28,300 stars on GitHub and is developed by the Manaflow team with very active releases. Working with coding agents changes what a terminal must do: sessions run for minutes unattended, several agents work in parallel, and the important moments are when an agent finishes or asks a question. cmux is built around that rhythm. Vertical tabs make dozens of sessions scannable, notifications surface when an agent completes a task or needs input, and the layout is programmable so workspaces for different projects can be restored instantly. Because it is based on Ghostty, it keeps the rendering speed and GPU acceleration terminal power users expect, while adding the agent-era features tmux setups have to bolt on.
cmux is free and open source. There is no paid tier; download it and use it with the coding agents and subscriptions you already have.
cmux is for macOS developers who run multiple AI coding agents in parallel and are tired of losing track of sessions in a generic terminal, and for power users who want tmux-style organization in a polished native app.