cmux

About

cmux is a free, open source, native macOS terminal built on Ghostty's libghostty rendering engine. It offers vertical tabs whose sidebar shows the git branch, working directory, ports, and notification text, along with horizontal and vertical split panes within each tab. Panes light up with notification rings when agents need attention, and an in-app browser can be split alongside the terminal.

For automation, cmux provides a CLI and socket API that let you create workspaces, send input, read screen contents, take screenshots, and drive the in-app browser. The app is built with native Swift and AppKit rather than Electron, and it supports extensive keyboard shortcuts. An iOS companion in beta lets you attach to your terminals from an iPhone or iPad.

cmux is listed as working with any command-line agent, and it can run over SSH, attach to remote tmux sessions, and restore windows, workspaces, panes, and scrollback when relaunched. Terminal themes and fonts follow your Ghostty config, while cmux-specific settings live in its own configuration file.