steam-local-mcp

Steam Local MCP

A free, open-source Windows Model Context Protocol server that lets an MCP-capable agent work with the Steam client installed for the current Windows user.

Ask an agent to find an installed game, launch it, open its Steam page, check local download/update status, search the Store, or summarize Steam-library storage. Steam starts quietly in the background when a requested client action needs it.

This is a standard stdio MCP server. It is agent-neutral: use it with Codex, Claude, or any other MCP client that can run a local command.

Example Usage

User: "Pick a strategy game for me to play."

Agent: 🛠️ Calling steam_list_games()

Agent: "How about Balatro? Should I launch it?"

User: "Yes."

Agent: 🛠️ Calling steam_launch_game(app_id: 2861700)

Agent: "Launched Balatro."

What it can do

Local Steam tools — no API key

• steam_list_games and steam_find_game — inspect locally installed games across all configured Steam libraries.
• steam_launch_game — launch one installed game by name or app ID.
• steam_get_game_install_status and steam_get_download_status — inspect manifest-recorded install, update, download, and paused-download states.
• steam_get_library_storage — show installed sizes and free disk space for every local Steam library.
• steam_open_library_page, steam_open_store_page, and steam_open_client_page — navigate the Steam client.
• steam_install_game — ask Steam to install an app ID; Steam validates ownership and manages the install flow.
• steam_client_status — report the detected Steam installation, discovery source, and whether Steam is running.

Public Store tools — no API key

• steam_search_store — find Store app IDs from a game name.
• steam_get_game_details — get public metadata, price, genres, release date, and Metacritic score.

Optional account tools — Steam Web API key required

Set STEAM_API_KEY and STEAM_ID to enable:

• steam_api_status — verify if API credentials are configured, valid, and connected to Steam's Web API.
• steam_get_library — owned games, playtime, last played, filtering, and pagination.
• steam_get_recently_played — recently played games, ordered by two-week playtime.

Requirements

• Windows 10 or newer
• Steam installed for the current Windows user
• Node.js 20 or newer

Install from npm

To install the published package via npm, add this equivalent configuration to your MCP client:

{
  "mcpServers": {
    "steam": {
      "command": "npx",
      "args": ["-y", "steam-local-mcp"]
    }
  }
}

The configuration-file location differs by agent, but the command and arguments above remain the same. Restart or reconnect your MCP client after saving its configuration.

To confirm your install manually, run:

npx -y steam-local-mcp print-config

Install from source

Use this when developing, auditing the source, or before an npm release is available:

git clone https://github.com/Jackson-Brooks/steam-local-mcp.git
cd steam-local-mcp
npm install
npm run build

Then configure your MCP client to run the compiled entry point from the directory you cloned:

{
  "mcpServers": {
    "steam": {
      "command": "node",
      "args": ["C:\\path\\to\\steam-local-mcp\\dist\\src\\index.js"]
    }
  }
}

Replace C:\path\to\steam-local-mcp with your own clone location. Do not use another user's path.

Optional Steam Web API configuration

Pass credentials through your MCP client's environment configuration or the operating-system environment:

{
  "mcpServers": {
    "steam": {
      "command": "npx",
      "args": ["-y", "steam-local-mcp"],
      "env": {
        "STEAM_API_KEY": "your_key",
        "STEAM_ID": "your_64_bit_steam_id"
      }
    }
  }
}

The server never loads a .env file automatically. Never commit credentials. Steam profile and game-details privacy settings can prevent account tools from returning data; local client controls still work for private profiles.

Getting your Steam API credentials

1. Sign in to Steam in a browser and open the Steam Web API key page.
2. Create or copy your key, then set it as STEAM_API_KEY in your MCP client's environment configuration. Keep it private.
3. Set STEAM_ID to your numeric 64-bit Steam ID, not your account name. It is commonly visible in a profile URL such as https://steamcommunity.com/profiles/7656119....
4. Restart or reconnect your MCP client, then call steam_api_status to confirm that the credentials are configured.

With the key configured, an agent can answer requests such as “show my unplayed Steam games” or “what have I played recently?” The key is optional: launching games, local install status, storage, Store search, and Store metadata work without it.

Steam detection and local status

Steam Local MCP checks, in order:

1. STEAM_PATH — either the Steam directory or its steam.exe
2. Current-user and machine Valve registry keys
3. Conventional per-user, Program Files, and C:\Steam locations
4. steam.exe on PATH

Use steam_client_status to see the selected path and discovery source. For a portable or unusual custom-drive install, set STEAM_PATH to the directory containing steam.exe.

Installation/download tools read Steam's local app manifests. needs_update: true means Steam has already recorded an update as pending. false means no pending update is currently recorded locally; it does not force a network update check.

Privacy and safety

• Local tools read local Steam files and open Steam URIs; they do not require a Steam Web API key.
• steam_launch_game only launches games found in a local installed-game manifest.
• Steam starts hidden when required for an action, rather than opening a visible launcher window first.
• There is no purchase or uninstall tool.
• Public Store descriptions are omitted by default. If explicitly requested, descriptions are capped, converted to plain text, and marked as untrusted external content.
• Web API and Store responses are cached locally under %LOCALAPPDATA%\steam-local-mcp\cache by default. Set STEAM_MCP_CACHE_DIR to override it, and call steam_refresh_cache to clear it.

Development

npm install
npm test
npm pack --dry-run

The test suite includes local parsing/caching tests, mocked Store and API tests, all-tool MCP protocol tests, and a real stdio handshake for the packaged entry point.

Contributing

Issues and pull requests are welcome. Please include a regression test for behavior changes, and keep destructive Steam operations out of scope unless they are explicitly designed and documented.

License

MIT