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

Tool	Purpose
chess_get_profile	Public profile — name, title, country, followers, join date
chess_get_stats	Ratings and W/L/D per format (bullet, blitz, rapid, daily, puzzles)
chess_get_current_games	Daily/correspondence games in progress; onlyMyTurn filters to games awaiting a move
chess_get_game_archives	Index of available monthly archive URLs for a player
chess_get_games_by_month	Every game a player played in a given year/month, with PGNs
chess_get_titled_players	Usernames holding a given title (GM, IM, FM, …)
chess_get_leaderboards	Current Chess.com leaderboards across all categories
chess_get_club	Club profile by URL-ID
chess_get_clubs	Clubs a given player belongs to

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.