Chess.com MCP (interactive views) Server

A reference example for building MCP apps with interactive React views — where each tool ships with its own view instead of returning plain text. Built with Skybridge, it looks up Chess.com players, games, and the daily puzzle, and runs in ChatGPT and Claude.

Try it

• Live demo: chess.niklas.sh
• MCP server URL: https://mcp.chess.niklas.sh/mcp

Just add the MCP server URL to any compatible client (ChatGPT, Claude, etc.) — that's it. Then ask things like "show me magnuscarlsen's last game" or "give me today's chess puzzle".

Tools

Tool	Input	Description
get-chess-player	username	Player profile with rapid, blitz, and bullet ratings plus win/loss/draw records.
get-last-game	username	The player's most recent game — result, opponent, opening, and an interactive board replay.
get-daily-puzzle	none	The Chess.com daily puzzle as an interactive board: solve it move by move with live feedback, reveal the solution, or reset and retry.

Getting Started

Prerequisites

• Node.js 24.14.1+
• pnpm 9+

Install

pnpm install

Start the dev server

pnpm dev

This starts:

• The MCP server at http://localhost:3000/mcp.
• The Skybridge DevTools UI at http://localhost:3000.

All scripts (dev, build, test, lint, typecheck) are defined in package.json.

Project Structure

├── src/
│   ├── server.ts         # Server entry: tool definitions + analytics middleware
│   ├── chess-com.ts      # Typed Chess.com API client (zod boundary + helpers)
│   ├── analytics.ts      # PostHog wrapper (no-op without a key)
│   ├── helpers.ts        # Typed useToolInfo / useCallTool hooks
│   ├── views/            # One React view per tool
│   │   └── shared/       # Shared view code (chess board, helpers)
│   └── index.css         # Global styles
├── vite.config.ts        # Vite + Skybridge + Tailwind config
├── Dockerfile            # Cloud Run image
└── package.json

Testing

Test the app locally using the DevTools UI at http://localhost:3000 while running pnpm dev.

Unit tests run with Vitest: pnpm test.

To connect with web clients like ChatGPT or Claude, expose your server with the --tunnel flag (pnpm dev:tunnel). See the test guide.

Deployment & Analytics

This app deploys to Google Cloud Run via release-please, and tool calls can be tracked with PostHog (no-op unless configured). See docs/deployment.md for the full setup.

Resources

• Skybridge Documentation
• Apps SDK Documentation
• MCP Apps Documentation
• Model Context Protocol Documentation

License

The source code is released under the Beerware License.

The chess piece icons are from the "Chess" pack on Flaticon and are used under the Flaticon Free License — they are not covered by the Beerware license. See NOTICE for details.