Demo

Play chess against AI directly inside ChatGPT, Claude, or VS Code.

What you're seeing

• A single-player chess game started via the play_computer tool
• The board renders inside the assistant's conversation
• Moves are made by clicking squares, with no typing required
• The AI opponent picks its own moves, using whatever the assistant supports

How it works

1. The MCP server registers a ui:// resource containing the chess UI
2. When the LLM calls play_computer, the host renders the board in a sandboxed iframe
3. The UI communicates with the server via tools/call over postMessage
4. AI moves: the built-in Stockfish engine plays on the server at levels 1-6. When the assistant itself is the opponent, the board asks it to call llm_move on its turn.