# MultAI

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Arya Gupta](https://cerebralvalley.ai/u/aryagupta)
- **GitHub:** https://github.com/aryagupta-tech/MultAI
- **Demo video:** https://youtu.be/IdmKgjTp1Ec
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1890

MultAI started with my dad. He was vibe coding his own website with an AI coding agent, got stuck, and asked me for help. There was no way for me to join his session. All I could do was ask for screenshots, have him copy-paste errors, and guess what the agent had already tried. Every AI coding agent today is single-player.

MultAI makes it multiplayer: one AI coding agent, shared live.

The host (my dad) runs the agent on his own computer, in a private git worktree of his real project. He sends me an invite link. I join from any browser, with no install and no API key, read a Muse Wonder catch-up brief of what happened so far, and direct the same agent he is using. Every file change and command, and every request I make, waits for his approval, so he always stays in control of his own code. Someone he admits stays until they leave or he removes them, and the link works until he revokes it.

What the demo shows, all live, nothing mocked:
- Point at the problem: click the broken thing on a screenshot and SAM 3.1 outlines its exact edges for the agent. No need to know what a CSS class is.
- look_at_app: the agent opens the app in a hidden browser and SAM 3.1 boxes each element it checks, so it verifies its own UI fix.
- /split: up to four agents work at once, each in its own git worktree, and their work is merged with git.
- Model handoff: switch models mid-chat and the new model inherits the conversation, the steps and the changed files.
- Android app: pair a phone with a one-time code and six matching digits, then send prompts, steer and approve each step from it. Every phone request is signed, and the computer checks it again.
- Muse Wonder drafts the pull request and credits who directed the agent. A read-only watch link replays the session.

It's for anyone building with AI who sometimes needs another person: parents and kids, students and teachers, teammates, open-source maintainers. Your code, keys and terminal never leave your machine.

Try it: macOS app and Android app at https://multai.si, browser version at https://app.multai.si

## More from Meta Global AI Developer Hackathon

- [AI Innovators](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1887)
- [SpriteForge](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1888)
- [Bluecoderhub](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1889)
- [Ad Astra Simul](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1891)
- [Apex](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1892)
- [arisris](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1893)

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Markdown version of https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/1890. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt