MAINS Lite
A free, open-source taste of MAINS.
MAINS Lite is a small, primitive, bring-your-own-key chat client that puts multiple AI models in the same conversation — with you. You send messages, they respond, and they respond to each other too, all in one thread you're actively part of. It's not the MAINS platform — no Scope Card deliberation modes, no Klaustrum, no accounts — just the one idea at the heart of MAINS, stripped down to something you can run yourself in five minutes.
What it does
Four AIs, one thread — and you're steering it.
You're in the conversation, not watching one
This isn't AIs debating in a box while you spectate. You send messages into the same thread whenever you want, and every AI reads and reacts to what you said — you're steering the turns, not just reading the transcript after the fact.
4 providers, one conversation
OpenAI, Anthropic (Claude), Google Gemini, and Groq — send to all of them at once, or target just one. Groq is the fast-inference host, and a different company from xAI: the Grok you meet in MAINS Council is not the Groq you meet here.
They read each other too
Every AI sees the full history, labeled by speaker, so replies address each other directly instead of talking past one another — on top of responding to you.
Scope Card
One shared context field, sent to every AI as part of its system prompt, so the whole conversation stays on the same page.
Nothing to sign up for
No account, no server, no MAINS billing. Bring your own API keys and they never leave your device.
Bring your own keys
Your keys never leave your device.
MAINS Lite has no backend. Whatever API key you paste in for OpenAI, Anthropic, Gemini, or Groq is saved only in your own browser's storage and sent directly from your device to that provider — never to a MAINS server, never logged, never seen by anyone but you. You're responsible for whatever usage those keys incur, same as using any provider's own console directly.
Run it yourself
Self-host it, or use the hosted version.
MAINS Lite is fully open source and MIT-adjacent source-available (PolyForm Noncommercial) — clone it, run npm install && npm run dev, and you're chatting locally on your own machine in a few minutes. The repo's README walks through it step by step, including a section for people who've never run a local dev server before, and how to reach it from your phone over Tailscale without exposing it to the public internet.
Or just use the hosted version at lite.mains-ai.app — same app, same guarantee that your keys stay on your device, no install required. It's also installable as a Google Play app on Android.
Want the real thing?
MAINS Lite is deliberately minimal — you can broadcast to every active AI or target just one, but there's no real turn dispatch behind it. MAINS itself is a genuinely human-orchestrated infrastructure: you dispatch each turn explicitly, pause and resume a thread whenever you want, intervene mid-conversation, and make every binding decision yourself — even Klaustrum, where AIs work the problem together autonomously, runs under a breaker that always surfaces back to you. Add structured Scope Cards, a public archive of past deliberations (MAINS Acta), decision memory, and a lot more.