The open-source terminal built for coding agents
cmux is the open-source terminal built for multitasking with coding agents. It has vertical tabs, notifications, a built-in browser, and it's built on Ghostty. When Claude Code needs you, the pane glows blue and the sidebar tells you why. No Electron/Tauri. Just Swift/Appkit.
cmux includes a scriptable in-app browser that can be split alongside the terminal. Agents can snapshot the accessibility tree, click elements, fill forms, and evaluate JavaScript, enabling direct interaction with localhost dev servers.
cmux supports Claude Code's teammate mode with native macOS splits, sidebar metadata, and notifications. The command 'cmux claude-teams' spawns teammates as native splits without requiring tmux, providing better performance and integration.
cmux reads existing ~/.config/ghostty/config for themes, fonts, and colors, and supports session restore on relaunch. This allows developers to maintain consistent terminal appearance and state across multiple workspaces without reconfiguration.
cmux provides notification rings, a notification panel, and sidebar indicators that light up when AI agents need attention. Users can jump to the most recent unread notification with Cmd+Shift+U, solving the problem of losing context across many parallel agent sessions.
cmux supports custom commands defined in cmux.json that launch from the command palette, and provides a CLI and socket API to create workspaces, split panes, send keystrokes, and automate the browser for project-specific workflows.