gamelibs-mcp

An MCP server that exposes your Steam, Epic Games Store, and IGDB game data as tools an MCP client (Claude Code / Desktop) can call.

• Steam — owned games, playtime, and installed-on-this-machine status.
• Epic — owned library + install status, via the reverse-engineered endpoints used by the open-source Legendary CLI / Heroic.
• IGDB — a games metadata database, for enriching/looking up game info.

Example prompt you could use once this MCP is set up:

Give me the top 5 of the games I own in my Steam and Epic library and I have not played yet but should play next.

I'm currently looking for a multiplayer game I can play online with my friends; since we played a lot of FPS games recently we want to try something different and more chill this time, maybe more collaborative like some Tower Defense or a Survival game.

Use the games I've already played as a baseline to get a sense of my overall taste but also don't hesitate to interview me to refine your understanding of what I am currently in the mood for.

Exposed Tools

• Steam — steam_list_games, steam_get_game_details, steam_resolve_user
• Epic — epic_auth_status, epic_get_login_url, epic_login, epic_list_games, epic_get_game_details
• IGDB — igdb_search_games, igdb_get_game_details, igdb_lookup_by_steam_appid
• Cache — refresh_cache (flush cached data so the next call re-fetches; the igdb_* tools also take force_refresh for refreshing specific games)

<details><summary>Design notes</summary>

• Lean responses. This keeps large libraries from blowing up the model's context.
  • Tools split into thin list tools (ids/titles only) and fat detail tools that take a sublist of ids.
  • Everything is paginated (limit/offset) and filterable server-side (search, installed_only, sort).
  • No image/cover URLs are ever returned
  • DLCs are excluded unless you pass include_dlcs=True.
• Per-machine install detection.
  • "Installed" data lives only in local files: Steam's .acf manifests, the official Epic Games Launcher's *.item manifests, and/or Legendary/Heroic's installed.json.
  • Run this server on the machine you actually game on to get real install status.
  • Owned/playtime data works from anywhere.
  • Windows, macOS, and Linux layouts are supported (the official Epic launcher is Windows/macOS only). </details>

Download the code

Requires Python 3.11+. Download or Clone the repo, then run it locally.

uv is recommended:

uv sync                     # or: pip install -e ".[dev]"

Configure your API keys

Credentials are read from environment variables:

Variable	Needed for	How to get it
STEAM_API_KEY	Steam	https://steamcommunity.com/dev/apikey
STEAM_ID or STEAM_VANITY	Steam	your SteamID64, or your /id/<slug> vanity name
TWITCH_CLIENT_ID / TWITCH_CLIENT_SECRET	IGDB	https://dev.twitch.tv/console/apps

Those will typically be provided as environment variables in your MCP client's configuration (e.g. claude_desktop_config.json, see "Set up in Claude" below), but can also be provided via a .env file (see "Contributing - Developer Tips").

[!NOTE]

• Epic does not need static secrets. If you already use Legendary/Heroic on this machine, Epic auth is bootstrapped from their local user.json. Otherwise, your MCP client is expected to call epic_get_login_url, have you open the returned URL in your browser to sign in to Epic like normal, then call epic_login(<authorizationCode>).
• For Steam, GetOwnedGames only returns data if your profile's Game details privacy is set to Public (and "Always keep my total playtime private" is off).

Set up in Claude

For Claude Code, you can add the MCP by running the following command from the cloned working copy directory:

claude mcp add gamelibs \
  --env STEAM_API_KEY=... --env STEAM_ID=... \
  --env TWITCH_CLIENT_ID=... --env TWITCH_CLIENT_SECRET=... \
  -- uv run --directory "$PWD" python -m gamelibs_mcp

If you are using Claude Desktop, go to "Settings" > "Developer" > "Edit Config" then add this to the claude_desktop_config.json file (see also .mcp.json.example):

  "mcpServers": {
    "gamelibs": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "--directory", "<mcp path on disk>", "python", "-m", "gamelibs_mcp"],
      "env": {
        "STEAM_ID": "<see above>",
        "STEAM_API_KEY": "<see above>",
        "TWITCH_CLIENT_ID": "<see above>",
        "TWITCH_CLIENT_SECRET": "<see above>"
      }
    }
  }

Be sure to replace the values of the env vars with your actual credentials (see above), as well as the <mcp path on disk> with the actual absolute path to where you cloned the repo (If you're on Windows, don't forget to escape backslashes (e.g. C:\\Users\\...) in that path).

Contributing - Developer Tips

Store your credentials in an .env file

The MCP can read your credentials from env vars declared in a local .env file too. Simply cp .env.example .env and fill it in with your actual credentials.

While this is not the ideal option for integrating the MCP in Claude (where you'd usually prefer to use claude mcp add gamlibs --env ... --env ... or the "env" attribute in the JSON config, like described above), having the ability to store your credentials in a local .env file can be very useful when working on the MCP's code itself for debugging or contributing, to avoid having to export them globally in your shell or having to pass them to every call while you test and iterate on the MCP.

On startup the server loads .env files searched from the directory it is launched in, upward. This works for uv run mcp dev … (launched from the project root) and for a claude mcp add … --directory <project> registration (launched in the project dir). It does not magically work if the server is launched from an unrelated directory.

Use the MCP Inspector to explore, debug and test the MCP

The MCP Inspector is a nice tool for developers who are working on any MCP. It's not specific to this gamelibs MCP in particular, but I find this useful so figured I'd share.

To use it, simply run this command from the root of your repo's working copy:

uv run mcp dev src/gamelibs_mcp/server.py

[!NOTE] This MCP Inspector requires Node.js / npx to run

Run Tests

uv run pytest        # offline unit tests (file-format parsing, install detection)

Disclaimer

The Epic integration talks to undocumented, reverse-engineered endpoints (as Legendary/Heroic do). It may break if Epic changes them, and is for personal use with your own account.