@coder/cmux

cmux - coding agent multiplexer

A 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 divergence
  • Local: git worktrees on your local machine (docs)
  • SSH: regular git clones on a remote server (docs)
• 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 →

Install

[!WARNING]
cmux is in a Preview state. You will encounter bugs and performance issues. It's still possible to be highly productive. We are using it almost exclusively for our own development.

Download pre-built binaries from the releases page for macOS and Linux.

More on installation →

Screenshots

Integrated code-review for faster iteration:

Agents report their status through the sidebar:

Git divergence UI keeps you looped in on changes and potential conflicts:

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

Project secrets help split your Human and Agent identities:

Stay looped in on costs and token consumption:

Opportunistic compaction helps keep context small:

TODO lists keep you informed on the agent's plan:

More reading

See the documentation for more details.

Development

See AGENTS.md for development setup and guidelines.

License

Copyright (C) 2025 Coder Technologies, Inc.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, version 3 of the License.

See LICENSE for details.