Persona.js

What is Persona.js?

Persona is a lightweight, open-source AI chat UI library that embeds into any website, from modern apps to static HTML. Unlike React-based chat frameworks, Persona is framework-free, backend-agnostic, and WebMCP-native, so your assistant can discover and execute tools exposed by the parent page. Add streaming chat, voice, theming, and interactive copilot experiences without rebuilding your frontend or writing bespoke APIs.

From the website

Persona: Open-source Agent UI Library in VanillaJS

Persona is an open-source, themeable AI chat widget you can add to any website in minutes. SSE streaming, agent loops, tool use, and style isolation: zero framework dependencies.