ESPN Fantasy MCP

A small, read-only Model Context Protocol server for ESPN Fantasy Football. It gives an MCP-compatible LLM access to normalized league snapshots, team rosters, and free-agent data.

This project calls ESPN's undocumented Fantasy read API. It is not an ESPN official developer integration, so endpoints and response shapes may change. Use it only with an account and leagues you are authorized to access, and review ESPN's terms before distributing or hosting it for other users.

What is included

The initial vertical slice exposes three read-only tools:

• get_league_snapshot: settings, teams, rosters, schedule, and status.

• get_team_roster: one normalized team and roster.

• get_free_agents: free agents and waiver players, with a bounded result set.

Write operations such as adding, dropping, trading, or setting a lineup are intentionally not included. ESPN's mutation requests are undocumented and can make irreversible league changes; they should be added only with a preview, explicit confirmation, and strong validation.

Related MCP server: sleeper-caffeine MCP

Requirements

• Python 3.11+

• uv or another Python package manager

• An ESPN Fantasy league ID and season year

• ESPN_S2 and ESPN_SWID cookies for private leagues

Install

uv sync --extra dev
cp .env.example .env

Fill in .env with your own values. Do not commit .env or put cookie values in prompts, tool arguments, logs, or source control.

For a private league, the cookies are the values named espn_s2 and SWID in your authenticated ESPN browser session. The server reads them only from environment variables. Public leagues may work without them.

Run

For a local MCP host that launches stdio servers:

uv run espn-fantasy-mcp

Example generic MCP configuration:

{
  "mcpServers": {
    "espn-fantasy": {
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "/absolute/path/to/EspnMCP",
        "espn-fantasy-mcp"
      ],
      "env": {
        "ESPN_S2": "your-cookie-value",
        "ESPN_SWID": "your-cookie-value",
        "ESPN_BASE_URL": "https://lm-api-reads.fantasy.espn.com"
      }
    }
  }
}

The server does not need to know a default league: tools receive league_id and season explicitly, which makes accidental cross-league access less likely.

Test and lint

The tests mock ESPN and never contact the live service:

uv run pytest
uv run ruff check .

Architecture

MCP host / LLM
       |
       v
src/espn_mcp/server.py       Tool schemas and MCP transport
       |
       v
src/espn_mcp/espn.py         ESPN HTTP adapter and normalization
       |
       v
ESPN Fantasy read API        Undocumented, cookie-authenticated for private leagues

The adapter isolates ESPN-specific payloads from the MCP layer. If ESPN changes hosts, views, filters, or response shapes, update espn.py and its fixtures rather than changing tool contracts.