reachat

reachat provides open-source UI building blocks for LLM and ChatUIs for ReactJS. It enables developers to bring conversational AI capabilities to applications without spending weeks building custom components. It is not coupled to any particular backend or LLM, so it can be used with any backend or LLM of choice, and aims to be highly customizable while keeping ease of use and performance. The tool targets React developers who need flexible, production-ready chat interfaces.

reachat is built on Tailwind CSS to allow customization of every aspect of the chat UI. It offers rich media support with markdown rendering, image and video embeds, multi-file uploads, and a pluggable remark plugin pipeline, emphasizing configurability and extensibility.

the Component Catalog lets the model render real React components—charts, cards, layouts—directly from the model’s response. reachat is provider-agnostic, enabling plugging in OpenAI, Anthropic, or a custom API, and also provides a built-in useAgUi hook for the AG-UI protocol.

reachat is Apache 2.0 licensed and free to use in personal or commercial projects, and supports built-in mentions and slash commands, slots for swapping components, and a focus on open-source collaboration and customization.

Use cases

• Use reachat to build chat interfaces that work with any backend or model.