chesscom-mcp

An MCP server over the Chess.com public data API. Read-only, and the upstream API needs no authentication — there is no token to manage and nothing to expire, which makes this the simplest of the set.

Runs over stdio and is registered in ~/.claude.json as chesscom.

Tools

Related MCP server: MCP Chess Server

Layout

src/client.js   thin fetch wrapper over api.chess.com/pub, shared error handling
src/chess.js    all nine tool registrations
src/index.js    McpServer construction + stdio transport

Running it

npm ci
npm start        # stdio server; expects an MCP client on the other end

Registered for Claude Code with:

claude mcp add chesscom -- node <path>/chesscom-mcp/src/index.js

Tests

npm test

Registration plus the fetch wrapper's URL, headers and error handling, using a stubbed fetch. No network calls, so it is safe in CI.

Notes

• The upstream API is rate-limited but generous, and serves cached responses. Bursts of chess_get_games_by_month across many months are the realistic way to hit a limit.

• Usernames are case-insensitive upstream but are URL-encoded here before use.

• credentials/ and .env are gitignored on principle even though this server has no secrets today — so that adding auth later can't leak one by accident.