💬 assistant-ui - Open Source Typescript/React Library for AI Chat
The UX of ChatGPT in your own app, connected to your own AI agents.
Hi YC! I’m Simon, building assistant-ui, an open source Typescript/React library for AI chat.
Hundreds of projects use assistant-ui to build in-app AI assistants, including companies like:
With >50k+ monthly downloads, assistant-ui is the most popular UI library for AI chat.
Getting Started
You can get started by running `npx assistant-ui create` (new project) or `npx assistant-ui init` (existing project) in your terminal.
Features
- Pre-built components, fully customizable
- Connects to your backend
- We have first class integration for AI SDK and LangGraph or build your own
- Generative UI: Map LLM tool calls and JSONs to custom UI components
- Frontend Tool Calls: Let LLMs take action in your frontend app
- Human Tool Calls: Human approvals and input collection
- Chat history and analytics via assistant-cloud (the hosted offering)
Customization
The API of assistant-ui is inspired by libraries like Radix UI and cmdk. Instead of a single monolithic chat component, we give you composable primitives and a great starter configuration. You have full control over the look and feel of every pixel while leaving auto-scrolling, LLM streaming and accessibility to us.
Sample customization to make a perplexity lookalike:
Demo Video
About
I’ve wanted to build my own dev tool company since high school. Last year, I built the first version of assistant-ui because I needed the UX of ChatGPT in my own app. The app I was building didn’t work out, but few friends asked me about the chat UI. Since then, AI chat has became increasingly popular as a means for delegating tasks to AI agents. My focus is on enabling human <> agent collaboration through better UX and AX (agent experience).
