FIDE Laws of Chess — Claude Code MCP server: what it does
Executes formal 2023 FIDE chess rules to evaluate arbiter cases and tournament penalties. Useful for checking claims around illegal moves or flag falls.
claude mcp add --transport http fide-chess https://mcp.arxo.io/mcp/fide-chessWhat FIDE Laws of Chess does
The server wraps a codified model of the FIDE Laws of Chess effective 1 January 2023. It evaluates factual assertions against strict rules, outputting whether an outcome is proven or marked as requiring arbiter discretion. Ten retained scenarios test specific tournament disputes such as touch-move intentions or second completed illegal moves.
Local execution via stdio relies on Node.js 20 or newer running on Linux x64 or macOS arm64. Users can also connect to the remote HTTP endpoint without maintaining local dependencies. If queries take longer to respond, execution time limits adjust via the FIDE_CHESS_MCP_CALL_TIMEOUT environment variable.
This package functions as a legal reasoning system rather than a chess engine — it cannot evaluate board positions, so users must supply factual premises explicitly.
What it helps with
- evaluate game outcome after a second illegal move
- determine draw validity upon flag fall when checkmate is impossible
- calculate penalty time for illegal moves in rapid or blitz formats
- verify move recording requirements during severe time pressure
Example prompts for the agent
- Evaluate the
SecondIllegalNoMatecase with FIDE Laws of Chess to see if the game ends in a draw. - Check the
FlagFallscenario under 2023 FIDE rules to verify whether a loss is computed. - Inspect arbiter penalty time in rapid chess using the
RapidFirstIllegalcase.
How to install FIDE Laws of Chess
1Platform CLI: remote server
claude mcp add --transport http fide-chess https://mcp.arxo.io/mcp/fide-chess2Platform CLI
claude mcp add --env FIDE_CHESS_MCP_CALL_TIMEOUT=<FIDE_CHESS_MCP_CALL_TIMEOUT> --transport stdio fide-laws-of-chess -- npx -y @arxo/mcp-fide-chessReplace <…> with your own values
1Platform CLI: remote server
codex mcp add fide-laws-of-chess --url https://mcp.arxo.io/mcp/fide-chess2Platform CLI
codex mcp add fide-laws-of-chess --env FIDE_CHESS_MCP_CALL_TIMEOUT=<FIDE_CHESS_MCP_CALL_TIMEOUT> -- npx -y @arxo/mcp-fide-chessReplace <…> with your own values
Config file
{
"mcpServers": {
"fide-laws-of-chess": {
"url": "https://mcp.arxo.io/mcp/fide-chess"
}
}
}{
"mcpServers": {
"fide-laws-of-chess": {
"command": "npx",
"args": [
"-y",
"@arxo/mcp-fide-chess"
],
"env": {
"FIDE_CHESS_MCP_CALL_TIMEOUT": "<FIDE_CHESS_MCP_CALL_TIMEOUT>"
}
}
}
}Replace <…> with your own values
Config file
{
"servers": {
"fide-laws-of-chess": {
"type": "http",
"url": "https://mcp.arxo.io/mcp/fide-chess"
}
}
}{
"servers": {
"fide-laws-of-chess": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@arxo/mcp-fide-chess"
],
"env": {
"FIDE_CHESS_MCP_CALL_TIMEOUT": "<FIDE_CHESS_MCP_CALL_TIMEOUT>"
}
}
}
}Replace <…> with your own values
1Platform CLI: remote server
gemini mcp add -t http fide-laws-of-chess https://mcp.arxo.io/mcp/fide-chess2Platform CLI
gemini mcp add -e FIDE_CHESS_MCP_CALL_TIMEOUT=<FIDE_CHESS_MCP_CALL_TIMEOUT> fide-laws-of-chess npx -y @arxo/mcp-fide-chessReplace <…> with your own values
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about FIDE Laws of Chess
How to install FIDE Laws of Chess in Claude Code?
Run claude mcp add --transport http fide-chess https://mcp.arxo.io/mcp/fide-chess.
What does FIDE Laws of Chess do?
It applies 2023 FIDE regulations to structured incident facts, establishing computed rulings or flagging that an arbiter's judgment is required.
Can this server calculate legal chess moves on a board?
No, it does not analyze board geometry or move trees. It functions solely as a rule checker for declared tournament events and clock disputes.
