cmux

A native macOS terminal built on Ghostty (libghostty), designed for AI coding agent workflows. OpenAI’s codex-style vertical tabs allows users to manage projects.

• https://cmux.com
• GitHub: https://github.com/manaflow-ai/cmux

Why I switched#

I went from bare Ghostty splits → tmux → back to bare Ghostty → cmux. The key thing cmux adds over bare Ghostty is a vertical tab sidebar with stable naming (one tab per project), in-app web browser, plus a notification system that tells me when an agent needs attention. Ghostty’s native splits are fine but it renames tabs based on whatever process is running in the focused pane, which is annoying when each tab is a project. cmux solves this while keeping Ghostty’s speed and GPU-accelerated rendering.

See How I Use It for how this fits into my workflow.

Key features#

• Vertical tab sidebar — shows git branch, working directory, listening ports, and latest notification per workspace
• Notifications — panes show a visual indicator when agents need input; Cmd+Shift+U jumps to the most recent unread; cmux notify CLI integrates with Claude Code hooks
• Splits — horizontal and vertical, with tabs created within a split (not the other way around)
• Ghostty config compatible — reads ~/.config/ghostty/config for themes, fonts, colors
• Scriptable — CLI and socket API for creating workspaces, splitting panes, sending keystrokes
• Embedded browser — scriptable in-app browser that agents can interact with (snapshot accessibility trees, click, fill forms)

Install#

brew install --cask cmux