chess-support-mcp

Chess Support MCP Server

An MCP server that manages the state of a chess game for LLMs/agents. It intentionally does not suggest moves. Instead, it provides tools to:

• Create/reset game

• Add a move (UCI)

• List all moves

• Get last N moves

• Machine-friendly board JSON (square-to-piece map) in get_status()

• Check if a move is legal

• Get status (FEN, whose turn, check, game over, result)

Requirements

• Python 3.13+

• uv package manager

Run via uvx directly from GitHub (no local checkout)

You can run this MCP server without cloning by using uvx with a Git URL. Replace placeholders with your repo info and optional tag/commit.

Generic MCP config (Inspector-style):

{
  "servers": {
    "chess-support-mcp": {
      "transport": {
        "type": "stdio",
        "command": "uvx",
        "args": [
          "--from",
          "git+https://github.com/danilop/chess-support-mcp.git",
          "chess-support-mcp"
        ]
      }
    }
  }
}

Claude Desktop mcpServers example:

{
  "mcpServers": {
    "chess-support-mcp": {
      "command": "uvx",
      "args": [
        "--from",
        "git+https://github.com/danilop/chess-support-mcp.git",
        "chess-support-mcp"
      ]
    }
  }
}

The first run may take longer while uvx resolves and builds the package; subsequent runs use cache.

Configure as a local MCP server (JSON)

Use stdio with uv run (no hardcoded paths). Example generic JSON config:

{
  "servers": {
    "chess-support-mcp": {
      "transport": {
        "type": "stdio",
        "command": "uv",
        "args": ["run", "chess-support-mcp"]
      }
    }
  }
}

Include a local path to your project without hardcoding a specific one by using a placeholder and setting the working directory via cwd (preferred), or by passing --project:

Option A (preferred: set working directory):

{
  "servers": {
    "chess-support-mcp": {
      "transport": {
        "type": "stdio",
        "command": "uv",
        "args": ["run", "chess-support-mcp"],
        "cwd": "<ABSOLUTE_PATH_TO_PROJECT>"
      }
    }
  }
}

Option B (use uv's project flag):

{
  "servers": {
    "chess-support-mcp": {
      "transport": {
        "type": "stdio",
        "command": "uv",
        "args": ["run", "--project", "<ABSOLUTE_PATH_TO_PROJECT>", "chess-support-mcp"]
      }
    }
  }
}

Claude Desktop configuration (in its JSON settings), using mcpServers:

{
  "mcpServers": {
    "chess-support-mcp": {
      "command": "uv",
      "args": ["run", "chess-support-mcp"],
      "cwd": "<ABSOLUTE_PATH_TO_PROJECT>"
    }
  }
}

Tools (Methods)

• create_or_reset_game() → Reset to initial position. Returns status (with pieces map), and moves.

• get_status() → Returns FEN; side_to_move (white/black); fullmove_number; halfmove_clock; ply_count; last_move_uci; last_move_san; who_moved_last; check flags; is_game_over; result when over; and a pieces map for machine reasoning.

• add_move(uci: str) → Apply a move if legal (e.g., e2e4, g1f3, promotion like e7e8q). Returns { accepted, status } and, on success, also moves and moves_detailed. On failure returns { accepted:false, reason:"illegal"|"parse_error", expected_turn? } with status reflecting the unchanged position.

• is_legal(uci: str) → Check legality of a UCI move in the current position.

• list_moves() → All moves in UCI made so far.

• list_moves_detailed() → All moves with ply, side, uci, san.

• last_moves(n: int=1) → Last N moves in UCI.

• last_moves_detailed(n: int=1) → Last N moves with ply, side, uci, san.

• board_ascii() → ASCII board (optional, human-oriented). The normal API returns machine-friendly JSON in status.pieces.

API design notes

• Moves are always provided in UCI (e.g., e2e4, g1f3, promotions e7e8q). The server infers side-to-move from position; you never specify white/black when sending a move.

• get_status().side_to_move tells the model whose turn it is. who_moved_last, last_move_uci, and last_move_san help with context.

• Detailed move lists are provided in separate *_detailed tools to keep the basic list simple and backwards compatible.

Notes

• The server maintains one in-memory game.

• The server does not provide hints or best moves.

Development

• Run tests:

uv run pytest -q