{"id":98405,"title":"cmux: the open source terminal built for coding agents","tagline":"Native macOS Ghostty-based terminal with vertical tabs, notifications, and built-in browser","body":"**TL;DR**\n\ncmux is a Ghostty-based terminal with vertical tabs, notifications, and in-app browser, built for multitasking with coding agents.\n\ncmux is trusted by thousands of builders from Nvidia, Google, OpenAI, and more. In two weeks, we’ve gained 17k GitHub stars.\n\n\u003chttps://github.com/manaflow-ai/cmux\u003e\n\n\u003chttps://www.youtube.com/watch?v=i-WxO5YUTOs\u003e\n\n**Hey, we’re Austin and Lawrence.**\n\nThe future is pointing towards an IDE-less world. In fact, the best engineers have already stopped using VS Code and Cursor.\n\nBoris Cherny, the creator of Claude Code, has not opened an IDE since last November. No one knows what the best workflow looks like yet, but it has never been more urgent to experiment with AI or be left behind.\n\nBut our current tools aren’t built for this. If you try running multiple Claude Code or Codex sessions in a standard terminal, you’ll find yourself in the midst of chaos. On the flip side, GUI orchestrators lock you in and lack the flexibility for experimentation.\n\n**That’s why we built cmux: an open-source terminal primitive for exploring the future of agent-driven workflows.**\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/db7fb781-3b9c-464d-9363-8f25a7b4aa3c)\n\nWe wanted a lightning-fast native macOS (Swift/AppKit) terminal with features you need for managing fleets of coding agents:\n\n* Vertical tabs\n* Blue rings around panes that need attention\n* Built-in browser\n* Based on Ghostty\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/3128b3c6-1fba-4b9c-a287-13ef7c2d04ce)\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/0e4d8185-428a-458d-9b92-987a7189f889)\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/2d0b0af2-5317-419a-84af-c920874d961d)\n\ncmux also has a built-in CLI that allows coding agents to command cmux’s browser, create new workspaces, and start off other agents in new terminals. AI can use cmux exactly like you would.\\\n\\\n\u003chttps://www.youtube.com/watch?v=XKc1cVCFLDQ\u003e\n\n**The zen of cmux**\n\ncmux is not prescriptive about how developers hold their tools. It's a terminal and browser with a CLI, and the rest is up to you.\n\ncmux is a primitive, not a solution. It gives you a terminal, a browser, notifications, workspaces, splits, tabs, and a CLI to control all of it. cmux doesn't force you into an opinionated way to use coding agents. What you build with the primitives is yours.\n\nThe best developers have always built their own tools. Nobody has figured out the best way to work with agents yet, and the teams building closed products definitely haven't either. The developers closest to their own codebases will figure it out first.\n\nGive a million developers composable primitives and they'll collectively find the most efficient workflows faster than any product team could design top-down.\n\ncmux is free, open-source (AGPL), and already trusted by thousands of builders from Nvidia, Google, OpenAI, and more. Developers build or port their own custom harnesses and orchestrators on top of cmux.\n\n\u003chttps://github.com/manaflow-ai/cmux\u003e\n\n**Traction**\n\nIn two weeks, cmux grew from zero to 3.5k GitHub stars.\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/67e21a8c-3bc8-44e2-b310-9584a238775b)\n\nWe peaked at #2 on Hacker News: \u003chttps://news.ycombinator.com/item?id=47079718\u003e\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/97569e3c-fdf9-4955-a675-4b64cc0919c2)\n\nOur X launch went viral: \u003chttps://x.com/lawrencecchen/status/2026729219154378912\u003e\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/829277d1-b53c-4800-9f5c-1f449b2bbe62)\n\nMitchell Hashimoto, the creator of Ghostty and founder of HashiCorp, shouted out cmux on X.\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/ad536752-35d4-4ee0-9282-06d3a8feca23)\n\nNick Schrock, the creator of Dagster and GraphQL:\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/000699e9-4c69-471c-9096-678bd2ccd121)\n\nEdward Grefenstette, Director of Research at Google DeepMind:\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/e9c2b0b5-a3f5-4cee-bf61-87411a167143)\n\nMany Japanese fans:\n\n![uploaded image](/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/4aa84dec-c312-4ad9-af6e-db89184e2f2f)\n\n**How you can help**\n\nStar our GitHub repo: \u003chttps://github.com/manaflow-ai/cmux\u003e\n\nTry cmux: [https://www.cmux.com/](https://www.cmux.dev/) \n\nShare cmux with your friends: send feedback to [founders@manaflow.ai](mailto:founders@manaflow.ai).","slug":"PbB-cmux-the-open-source-terminal-built-for-coding-agents","created_at":"2026-03-03T17:31:16.700Z","updated_at":"2026-05-25T01:56:57.396Z","total_vote_count":731,"url":"https://www.ycombinator.com/launches/PbB-cmux-the-open-source-terminal-built-for-coding-agents","share_image_url":"https://www.ycombinator.com/media/?type=post\u0026id=98405\u0026key=user_uploads/760906/db7fb781-3b9c-464d-9363-8f25a7b4aa3c","company":{"id":29719,"name":"Manaflow","slug":"manaflow","url":"https://www.cmux.com","logo":"https://bookface-images.s3.amazonaws.com/small_logos/f240894ee1866a817f8d66f9ed82314520294cbf.png","batch":"Summer 2024","industry":"B2B","tags":["Developer Tools","Open Source","AI"],"search_path":"https://bookface.ycombinator.com/company/29719"}}