Open source UI. Hosted persistence when you need it.
The library is free forever under MIT. assistant-cloud is an optional backend for threads, history, and auth if you do not want to run that yourself.
The library
TypeScript and React for AI chat. Keep your backend. Customize every surface.
- MIT licensed
- Use the library in any product, including commercial ones. The source stays on GitHub.
- Your own backend
- Pair it with any runtime you already run. Cloud is optional, not a requirement.
- React, React Native, and Ink
- One chat model across web, native, and terminal. Keep the same runtime adapters.
- Runtime adapters
- AI SDK, LangGraph, and other backends plug in without rewriting the UI.
assistant-cloud
Hosted thread persistence, history, and user-scoped storage. Use it with assistant-ui or your own UI.
Free
$0
Try hosted persistence on a small project.
- 200 MAU included
- Thread persistence and history
- Thread list and auto-generated titles
- User and workspace authorization
Pro
$50/mo
For products that are starting to grow.
- 500 MAU included
- $0.10 per additional MAU
- Everything in Free
- Early access to new features
Enterprise
Custom
For teams that need their own backend and an SLA.
- Custom MAU pricing
- Your own backend integration
- Data replication
- Dedicated support
- 99.99% uptime SLA
- On-premises deployment
MAU means monthly active users who send at least one message. For consumer apps, write for B2C pricing.
What Cloud includes
The same product on every plan. Higher tiers add volume, a custom backend, and an SLA.
- Thread persistence
- Messages save as the conversation streams. Users can leave and pick up later.
- Thread list
- Browse, switch, rename, archive, and delete conversations from the UI or hooks.
- Auto-generated titles
- New threads get a title from the first exchange. No extra request to wire up.
- User and workspace auth
- Scope history to a user or workspace with Clerk, Auth0, Supabase, Firebase, or your own provider.
Questions
- Do I need Cloud to use the library?
- No. assistant-ui is a free TypeScript and React library. You can keep your own backend and never open a Cloud account.
- What counts as an MAU?
- A monthly active user is someone who sends at least one message in that month. Viewers who never send a message do not count.
- What if I have a consumer app?
- The plans above are sized for B2B products. For B2C pricing, write to [email protected].
- Can I bring my own database?
- The open source library always lets you persist threads yourself. Enterprise Cloud also includes integration with your own backend, plus replication and on-premises deployment.
Start with the library, add Cloud later.