Pydantic AI Chat UI

A React-based chat interface for Pydantic AI. This package powers the documentation assistant at ai.pydantic.dev/web/.

Built with Vercel AI SDK and designed to work with Pydantic AI's streaming chat API.

Features

• Streaming message responses with reasoning display
• Tool call visualization with collapsible input/output
• Conversation persistence via IndexedDB, with migration from legacy localStorage data
• Dynamic model and tool selection
• Dark/light theme support
• Mobile-responsive sidebar

Hosting below a path prefix

Set the startup configuration before the UI's module script executes when the app is served below a same-origin path prefix:

<script>
  window.PYDANTIC_AI_CHAT_CONFIG = {
    basePath: '/chat/',
    apiPath: '/chat/api/',
  }
</script>

basePath controls conversation URLs and browser navigation. apiPath is the complete directory containing the configure and chat endpoints; it is independent of basePath, so a UI below /chat/ may still use /api/. Both values accept same-origin paths and are normalized with a trailing slash.

Without startup configuration, basePath uses the normalized Vite base (offline and CDN builds use /) and apiPath uses /api/. This configuration also works when a server injects the script into the single-file offline artifact at request time; the artifact does not need to be rebuilt.

Development

pnpm install
pnpm run dev:server  # start the Python backend (requires agent/ setup)
pnpm run dev         # start the Vite dev server

License

MIT