threejs-server.md

Three.js MCP App

MCP App · UI in chatFeatured

from"modelcontextprotocol"

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Three.js Server is an official example in modelcontextprotocol/ext-apps. It binds a tool result to a ui:// resource and renders an interactive Three.js scene inside hosts that implement MCP Apps.

Not for: A complete 3D editor, asset pipeline or game engine. It is an example application for demonstrating embedded MCP UI.

Source and setup verified on 2026-11-03

Visualization

3DThree.jsWebGLvisualization

View on GitHub

Quick facts

Provider: Model Context Protocol project (official example)
Framework: Three.js / WebGL
Protocol: MCP Apps ui:// resource
Repository stars: 3,042 on 2026-11-03

What you can do

Render a 3D scene inline
Orbit and inspect the scene interactively
Receive structured tool data from the server

Requirements

Node.js and npm
An MCP Apps-compatible host
A browser runtime with WebGL

setup.md

# 1. Clone the examples repository

$git clone https://github.com/modelcontextprotocol/ext-apps.git

# 2. Install and build

$cd ext-apps && npm install && npm run build

# Official example

https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/threejs-server

Use the current command in the example README after building the monorepo.

Always confirm the latest setup instructions with the maintainer before installing.

>Questions

Is Three.js MCP App an MCP App with inline UI?

Yes. The maintainer's source declares an MCP UI resource and links it to a tool result. It renders inline only in hosts that support MCP Apps.

Where were these details checked?

Against the maintainer's README, source, or official documentation at https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/threejs-server, plus the GitHub API where a repository is available.