cmux

Native macOS terminal for AI coding agents with vertical tabs, split panes, notifications, and a scriptable API.

Overview

cmux is a lightweight, native macOS terminal built on Ghostty, designed specifically for managing multiple AI coding agents and multitasking workflows. It features vertical tabs in a sidebar showing git branches and working directories, notification rings that alert you when agents need attention, split panes for organizing work, and an embedded browser with a scriptable API for automation.

The terminal is fully open source and free to use locally with your own API keys. It works with Claude Code, Codex, OpenCode, Gemini CLI, and any CLI-based agent. For teams and individuals who need cloud execution, paid plans offer isolated Cloud VMs where agents can run on remote infrastructure while you control them from your Mac.

Key features

Vertical tabs with git branch and directory info
Notification rings for agent attention alerts
Split panes (horizontal and vertical)
Embedded scriptable browser
Socket API for automation and CLI control
GPU-accelerated rendering via libghostty
Native Swift + AppKit (no Electron)
Session restore across restarts
Cloud VMs for remote agent execution
iOS companion app (beta)

Pros

Free and open source for local use
Native macOS performance without Electron overhead
Excellent for AI agent workflows with built-in notifications
Highly programmable via CLI and socket API
Seamless integration with Ghostty config for themes and fonts
Cloud VM support for running agents remotely
Active development with frequent updates

Cons

macOS only (no Linux or Windows support)
Requires macOS 14.0 or later
Cloud features require paid subscription
iOS app still in beta
Learning curve for advanced automation features

Use this if

You work with AI coding agents like Claude Code or Codex, need to manage multiple terminal sessions with clear organization, want a native macOS terminal optimized for agent workflows, or need cloud execution for remote agents.

Skip this if

You use Linux or Windows, need a terminal that works across multiple operating systems, prefer lightweight CLI-only tools without a GUI, or don't work with AI agents.

Best for

AI coding agent workflowsManaging multiple concurrent terminal sessionsDevelopers using Claude Code or other CLI agentsTeams running agents on remote infrastructureMultitasking developers who need organized workspaces