♟️ Chess MCP Server

Give your AI Agent eyes to see the board and hands to make the move.

This is not just a chess API. It's a Model Context Protocol (MCP) server designed to let Large Language Models (LLMs) like Claude play chess agentically.

Capable of visualizing the board in real-time HTML, understanding spatial relationships via Markdown, and challenging you with a hybrid difficulty engine (Levels 1-10)—or simply facilitating a game between you and your Agent.

🚀 Features

• MCP-UI Support: Interactive HTML board embedded directly in the chat (where supported).
• Hybrid AI Engine: Adjustable difficulty from "Random Blunderer" (Level 1) to "Minimax Master" (Level 10).
• Agent vs. Agent: Let two AI personalities battle it out.
• Web Dashboard: Automatically launches a local sidecar dashboard (http://localhost:8080) to monitor all active games.

🧰 Tools API

Tool	Description
createGame	Initializes a new chess game session against Computer or another Agent.
joinGame	Joins an existing game using its Game ID.
finishTurn	Submits a move (algebraic or UCI) and optionally claims a win.
waitForNextTurn	Long-polling tool that waits for the opponent's move.

For full specification, see docs/spec/tools.md.

📦 Installation

Prerequisites

• Python 3.10+
• An MCP Client (e.g., Claude Desktop, Cursor)

1. Installation

You can install directly from PyPI:

pip install chess-mcp-server

2. Configure MCP Client

Add the following to your MCP Client configuration file (e.g., ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "chess": {
      "command": "uvx",
      "args": ["chess-mcp-server"]
    }
  }
}

Alternatively, using pip installation:

{
  "mcpServers": {
    "chess": {
      "command": "python",
      "args": ["-m", "src.mcp_server"]
    }
  }
}

🛠️ Development

If you want to modify the code:

1. Clone & Setup

   git clone https://github.com/fritzprix/chess-mcp-server.git
   cd chess-mcp-server
   
   python -m venv .venv
   source .venv/bin/activate
   pip install -e .
   

🎮 How to Play

Once the server is connected, you can ask your Agent to start a game.

Start a Game

Ask: "Start a new chess game against the computer at level 5."

• The Agent calls createGame.
• Pro Tip: You can also ask "I want to play against YOU. Create a game where you are White."

Join an Existing Game

If you have a Game ID (e.g., from another agent), you can ask: "Join game [Game_ID]".

• The Agent calls joinGame.

The Game Loop

1. Your Move:
   • Interact with the HTML Board if shown. Drag your piece and click Confirm.
   • Or tell the Agent: "Move pawn to e4."
2. Agent's Turn:
   • The Agent calls waitForNextTurn.
   • It sees the board (Markdown or HTML) and thinks about the move.
   • It calls finishTurn to submit its move.
3. Checkmate:
   • If you deliver the final blow, you can check the "Claim Checkmate" box on the UI or tell the Agent "Checkmate!".

Dashboard

When the server starts, it will try to open http://localhost:8080. You can view the list of all active games and spectator views there.