uijit

UI Just-In-Time - MCP server for A2UI canvas rendering and Chromecast casting.

What is uijit?

uijit is an MCP (Model Context Protocol) server that enables AI agents to create rich visualizations using the A2UI component format and cast them to Chromecast/Google TV devices in real-time.

This repository also hosts the Canvas Receiver - a Google Cast receiver application served via GitHub Pages at uijit.com.

Installation

pip install uijit

Usage

As an MCP server (stdio transport)

uijit --host 0.0.0.0 --port 8090

With nanobot

Add to your nanobot config:

{
  "tools": {
    "mcpServers": {
      "uijit": {
        "command": "uijit",
        "args": ["--host", "0.0.0.0", "--port", "8090"]
      }
    }
  }
}

MCP Tools

How It Works

┌─────────────┐     ┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│  AI Agent   │────▶│   uijit     │────▶│   uijit     │────▶│ Chromecast  │
│  (nanobot)  │     │  MCP Server │     │  Receiver   │     │    TV       │
└─────────────┘     └─────────────┘     └─────────────┘     └─────────────┘
      │                   │                   │                   │
      │  A2UI JSON        │  WebSocket        │  Cast SDK         │
      │  (components)     │  (real-time)      │  (custom msg)     │

1. AI Agent generates A2UI visualization components via MCP tools
2. uijit MCP Server manages surfaces, renders HTML, serves via WebSocket
3. uijit Receiver (GitHub Pages) is loaded by Chromecast and connects to the server
4. Chromecast displays the live-updating visualization

URLs

Chromecast Casting

uijit includes a pre-registered Google Cast receiver (App ID: BE2EA00B) that points to https://uijit.com/canvas-receiver/. No registration is needed — casting works out of the box when paired with androidtvmcp.

Repository Structure

uijit/
├── index.html                 # Landing page (GitHub Pages)
├── canvas-receiver/
│   └── index.html             # Cast receiver application
├── pyproject.toml             # Python package metadata
├── src/uijit/                 # MCP server source
│   ├── cli.py                 # CLI entry point
│   ├── server.py              # MCP protocol handler
│   ├── canvas_manager.py      # Surface lifecycle management
│   ├── renderer.py            # A2UI → HTML renderer
│   ├── web_server.py          # HTTP/WebSocket server
│   └── models.py              # Data models
└── tests/
    └── test_canvas_manager.py # Tests

Related Projects

• androidtvmcp - MCP server for Android TV control

License

MIT