assistant-ui

Why we included this project

assistant-ui gives React teams the core pieces of a ChatGPT-style interface without making them hand-build every message bubble, streaming indicator, and tool-call widget. The package ships ready-made thread components plus a runtime layer that connects to the Vercel AI SDK, LangChain, or other backends, so wiring a model to a working front end doesn't require writing chat state management from scratch. Because the components sit on Radix and shadcn-style foundations, the UI tends to blend into an existing React design system rather than impose a foreign look, which matters when you are shipping a copilot or an in-app assistant on top of your current stack. If the built-in widgets fall short, lower-level primitives let you handle custom thread behavior, attachments, branching, and function-call rendering, and the same library also runs on React Native and in the terminal via Ink.