cmux - coding agent multiplexer

A cross-platform desktop application for parallel agentic development.

Why parallelize?

Here are some specific use cases we enable:

• Contextual continuity between relevant changes:
  • e.g. create a workspace for code-review, refactor, and new-feature
• GPT-5-Pro: use the slow but powerful GPT-5-Pro for complex issues
  • Run in the background for hours on end
  • The stream will automatically resume after restarts or intermittent connection issues. If the model completes early we will show an indicator.
• A/B testing: run multiple workspaces in parallel on the same problem but different approaches, abandon the bad ones.
• Tangent exploration: launch tangents in cmux away from main work

Features

• Isolated workspaces with central view on git status updates
• Multi-model (sonnet-4-*, gpt-5-*, opus-4-*)
• Supporting UI and keybinds for efficiently managing a suite of agents
• Rich markdown outputs (mermaid diagrams, LaTeX, etc.)

cmux has a custom agent loop, but, we are heavily inspired by Claude Code in our UX. You'll find familiar features like Plan/Exec mode, VIM inputs, /compact and new ones like opportunistic compaction and mode prompts.

📚 Read the full documentation →

Quick Install

Download pre-built binaries from the releases page:

• macOS: Signed and notarized DMG (separate builds for Intel/Apple Silicon)
• Linux: AppImage
• Windows: not implemented, coming soon

Screenshots

Mermaid diagrams make it easier to review complex proposals from the Agent

Development

See AGENTS.md for development setup and guidelines.