MUP (Model UI Protocol) gives LLMs interactive UI panels in the browser. The LLM controls them via function calls; the user interacts with them directly. Both sides see each other's actions in real time.

In the demo video, Claude narrates via TTS while simultaneously building an 8-slide presentation — with auto-generated charts, comparison tables, and live theme switching. Then it writes a dice roller from scratch (~50 lines of HTML), the server auto-detects it, and Claude rolls dice through it. All in under 6 minutes.

A MUP is just an HTML file. No build step, no framework:

npm install -g mup-mcp-server claude mcp add mup -- npx mup-mcp-server Then say "make me a presentation" in Claude Code.

Built-in MUPs: slides (with chart engine), voice (TTS/STT), chat, progress tracker. Or write your own — any HTML with a JSON manifest becomes a MUP.

It runs as an MCP server. The protocol spec is ~400 lines.

Demo: https://youtu.be/GKeDc1DMLH0?si=Y7zBPQ2_LoHRvnJf GitHub: https://github.com/Ricky610329/mup Spec: https://github.com/Ricky610329/mup/blob/main/spec/MUP-Spec.m...