Free and open source native macOS terminal built on Ghostty. Works with Claude Code, Codex, OpenCode, Gemini CLI, Kiro, Aider, and any CLI tool. Vertical tabs, notification rings, split panes, and a socket API.

Reid Burke

cmux is a free, open-source native macOS terminal built on libghostty (the rendering engine behind Ghostty), designed specifically for running multiple AI coding agents simultaneously. Key features include vertical tabs with git branch and port info in the sidebar, notification rings that light up when agents need attention, split panes, an embedded scriptable browser, and a CLI/socket API for full programmability. It supports all major CLI-based coding agents (Claude Code, Codex, OpenCode, Gemini CLI, Kiro, Aider, Cline, etc.) and can orchestrate multi-agent workflows by turning subagents into visible native panes. Built with Swift and AppKit (no Electron), it offers GPU-accelerated rendering, session restore across restarts, SSH/remote tmux support, and an iOS companion app in beta. The project is GPL-licensed and community-endorsed by notable developers including Mitchell Hashimoto (Ghostty/HashiCorp creator).

cmux — The terminal built for multitasking, organization, and programmability

<p>The notification rings solve the actual pain of multi-agent work — once you have 4+ agents running you lose track of which one is blocked on a confirm versus still churning, and tabbing through them to check is the real time sink. Surfacing git branch and port per pane in the sidebar is the other underrated bit; that’s usually the exact context I’m hunting for when I come back to a stalled agent and can’t remember which worktree it was on.</p>
