tool-ui

AI models call tools, and every one of those calls has to be shown to the user somehow. Tool-ui gives you pre-built React components for rendering those tool calls and their results inside a conversation UI.

This is a UI component library specifically for AI tool-calling interfaces. Instead of building your own "here's what the AI did" rendering from scratch, you get components that display tool invocations, streaming results, and error states. It's TypeScript, React-based, and designed to plug into assistant-ui (the parent project's chat framework).

Completely free. MIT license, and growing fast. Solo developers building AI chat products will save significant time here. If you're already using assistant-ui for your chat interface, this is the natural add-on. Small teams building internal AI tools get a polished UX without designing tool-call rendering from scratch.

The catch: it's nascent. That means a small community, potential breaking changes, and limited battle-testing. Tightly coupled to the assistant-ui ecosystem. If you're using a different chat framework, integration will take work.