steam-mcp-server

MCP server that exposes the Steam Web API as tools for Claude Desktop or Claude Code, running locally over stdio.

Available tools

The Steam profile being queried must be public, except when querying your own SteamID with your own API key. An API key is required for account-related tools; public tools such as current player counts and game search can run without one.

1. Get a Steam API key

Go to https://steamcommunity.com/dev/apikey, sign in with your Steam account, and generate an API key. Steam requires at least one game in your library to issue a key.

2. Installation

Requirements: Node.js 18 or later.

npm install
cp .env.example .env       # macOS/Linux
# Windows PowerShell: Copy-Item .env.example .env
# Edit .env and add your STEAM_API_KEY
npm run build

The .env file contains secrets and must not be published. If your network uses SSL inspection, set STEAM_EXTRA_CA to the path of your private CA certificate. Use STEAM_TLS_INSECURE=1 only as a last resort on a trusted network.

Steam responses are cached in memory for 30 seconds by default, and requests are spaced by at least 100 milliseconds to reduce rate-limit errors. Configure STEAM_CACHE_TTL_MS=0 to disable caching or adjust STEAM_MIN_REQUEST_INTERVAL_MS if needed.

Family library

Configure the SteamID64 values of family members as a comma-separated list. MY_STEAM_ID is included automatically:

MY_STEAM_ID=76561199080486814
STEAM_FAMILY_MEMBER_IDS=76561100000000001,76561100000000002

The get_family_owned_games tool returns each game's appid, name, and owner's SteamID64. If a game appears in multiple accounts, owner contains multiple IDs. The Steam Web API does not directly expose games borrowed exclusively through Steam Families; it only returns games that each account exposes as owned.

3. Test with MCP Inspector

This is recommended before connecting the server to a real client.

npm run inspector

This opens a browser UI where you can list and execute the tools manually to verify that they respond correctly.

To test the published npm package instead of the local build:

npx --yes "@modelcontextprotocol/inspector" npx --yes --package "@j.meyer/steam-mcp-server@1.1.6" steam-mcp-server

4. Connect to Claude Desktop

Edit the Claude Desktop configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

Add the server using the absolute path to your project:

{
  "mcpServers": {
    "steam": {
      "command": "npx",
      "args": [
        "--yes",
        "--package",
        "@j.meyer/steam-mcp-server@1.1.6",
        "steam-mcp-server"
      ],
      "env": {
        "STEAM_API_KEY": "your_api_key_here"
      }
    }
  }
}

Restart Claude Desktop. The steam server should appear in the tools menu.

5. Connect to Claude Code

claude mcp add steam -- npx --yes --package @j.meyer/steam-mcp-server@1.1.6 steam-mcp-server

Claude Code inherits STEAM_API_KEY if it is defined in your .env file or in the shell environment where you run claude.

Publishing the project

This server is designed to run locally over stdio. Each user must configure their own STEAM_API_KEY and MY_STEAM_ID. Never copy your .env file or include an API key in the published configuration.

Before creating a release, verify the installation from a clean copy:

npm ci
npm run build
npm test
npm run inspector

If you publish it as an npm package, npm publish builds the project automatically and only distributes dist, README.md, .env.example, and LICENSE. The package is available as @j.meyer/steam-mcp-server.

Automated releases

Pushing a tag matching vX.Y.Z runs .github/workflows/publish.yml. The workflow verifies that the tag matches the versions in package.json and server.json, runs the build, tests, audit, and package verification, then publishes to npm, the official MCP Registry, and GitHub Releases.

The workflow uses npm Trusted Publishing with GitHub OIDC, so no NPM_TOKEN secret is required. Before the first automated release, configure a Trusted Publisher in the npm package settings with:

• Provider: GitHub Actions
• User: julianmeyerr
• Repository: steam-mcp-server
• Workflow: publish.yml
• Allowed action: npm publish

The MCP Registry publication uses GitHub OIDC as well and requires no additional secret. The registry metadata is defined in server.json and ownership is verified through mcpName in package.json.

After merging the version bump into main, push its matching tag:

git push origin v1.1.6

License

This project is licensed under the MIT License. See LICENSE for details.

How to get a SteamID64

Most tools expect a 64-bit steamid (for example, 76561197960435530) rather than a username. You can use the resolve_vanity_url tool to convert a custom Steam URL, or use an external service such as SteamID.io.

Possible next steps

• Add more Steam Store tools, such as reviews, prices, and game details.