assistant-ui
Open-source React primitives for production-grade AI chat experiences.
About
assistant-ui is the most-starred dedicated AI-chat library on GitHub (around 12k stars, MIT, Y Combinator-backed): composable TypeScript/React primitives — thread, message list, input, tool-call renderers, approval cards — inspired by shadcn/ui, with adapters for the Vercel AI SDK, LangGraph, LangChain, and Mastra. It handles streaming, auto-scroll, retries, attachments, markdown, code highlighting, and voice input out of the box, plus human-in-the-loop tool approvals and generative UI.
It is a library, not a hosted product: you own the backend, the model keys, and the deployment, and wiring custom runtimes takes real engineering. Teams that want a chat UI without building message streaming and tool-call rendering from scratch get the most value; anyone expecting a drop-in ChatGPT clone should look at full apps like LibreChat instead.
What it can do
- Composable chat primitives (thread, messages, input)
- Streaming, retries, attachments, markdown rendering
- Tool-call rendering and human approval flows
- Adapters for AI SDK, LangGraph, LangChain, Mastra
- Broad provider support (OpenAI, Anthropic, Gemini, Bedrock, Ollama)
- Optional chat history and analytics via Assistant Cloud
Setup
npx assistant-ui@latest create for a new Next.js app, or npx assistant-ui@latest init to add components to an existing project; alternatively npm install @assistant-ui/react.
Prerequisites
A React/Next.js project and an LLM backend (AI SDK, LangGraph, Mastra, or custom); model API keys for your chosen provider.
Use cases
Works with
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 58; Trending score 82/100 from researcher assessment.
★ 12,000 GitHub stars
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.