SleepBot

An MCP server that connects Claude to fantasy football leagues. Phase 1: read-only tools over Sleeper's public API (no auth required). Built to extend to write actions, ESPN, and multiple leagues without changing the tool interface.

Architecture

The core is platform-agnostic. Every tool talks to a LeagueAdapter interface, never to a platform SDK directly:

tools ──▶ LeagueAdapter (interface) ◀── SleeperAdapter ──▶ api.sleeper.app
  │                                       (EspnAdapter later)
  └──▶ config (leagues[] registry)

Adding a league or a platform is a config change, not a code change. The architecture is mapped with Cairn in cairn.blueprint; run cairn scan to reconcile the map against the code.

Related MCP server: Yahoo Fantasy Baseball MCP

Setup

npm install
cp config/leagues.example.json config/leagues.json   # then edit with your league
npm run build

Find your Sleeper league id in the app URL or via https://api.sleeper.app/v1/user/<username>/leagues/nfl/<season>.

config/leagues.json

{
  "leagues": [
    {
      "id": "my-main-league",        // your own label, passed to every tool
      "platform": "sleeper",         // "sleeper" | "espn"
      "sleeper": { "leagueId": "123456789012345678", "username": "yourusername" }
    }
  ]
}

Secrets are never stored inline — a value like "env:ESPN_S2" is resolved from the environment at runtime (see .env.example). Phase 1 needs no secrets.

Run

npm start          # serves over stdio (built)
npm run dev        # serves over stdio (tsx, no build)

Register with Claude Code

// .mcp.json / claude mcp add
{
  "mcpServers": {
    "sleepbot": { "command": "node", "args": ["dist/index.js"] }
  }
}

Tools (Phase 1 — all read-only)

Every tool takes your leagueId label, so multi-league support is just "pass a different id." Set sleeper.username in config and rosters/standings/matchups are flagged with isYou, so SleepBot knows which team is yours without asking.

Run the tests with npm test.

Roadmap

• Phase 2 — Sleeper write actions (confirm-by-default) + rules engine (src/rules, stubbed)

• Phase 3 — local GUI (Vite/React) over the same tools

• Phase 4 — EspnAdapter against ESPN's cookie-based API, same interface