steam-mcp

MCP server for the Steam Web API. Exposes your game library, playtime, achievements, friends, wishlist, and the Steam store to MCP clients (Claude Code, Claude Desktop, etc.) over stdio.

Prerequisites

• mise (manages node + bun versions via .mise.toml)
• A Steam Web API key — get it here

Setup

mise install
bun install
Copy-Item .env.example .env
# edit .env and set STEAM_API_KEY + STEAM_DEFAULT_STEAM_ID

Run

bun run dev      # watch mode
bun run start    # one-shot

Hook into Claude Code

claude mcp add steam --scope user -- bun run "$(pwd)/src/index.ts"

Or add it to your MCP config directly:

{
  "mcpServers": {
    "steam": {
      "command": "bun",
      "args": ["run", "<path-to-steam-mcp>/src/index.ts"]
    }
  }
}

The .env file in the project root is loaded automatically.

Configuration

Variable	Required	Purpose
STEAM_API_KEY	For account data	Everything account-scoped: library, achievements, friends, vanity URL resolution. Sent as the x-webapi-key header so it never appears in a URL.
STEAM_DEFAULT_STEAM_ID	Recommended	Your SteamID64, used whenever a tool omits steam_id. Find it here.
STEAM_ACCESS_TOKEN	Wishlist writes only	User access token for add_to_wishlist / remove_from_wishlist.
STEAM_COUNTRY_CODE	No	Store region for prices. Defaults to US.
STEAM_LANGUAGE	No	Language for store text and achievement names. Defaults to english.

Store search, app details, reviews, player counts, news, and global achievement percentages work with no key at all.

Getting an access token

Wishlist writes are not covered by API keys — Steam requires a user access token instead. Log into Steam in a browser, open store.steampowered.com/pointssummary/ajaxgetasyncconfig, and copy the webapi_token value into STEAM_ACCESS_TOKEN. It expires roughly every 24 hours, so it needs periodic refreshing.

Tools exposed

Area	Tools
Users	get_player_summary, resolve_vanity_url, get_friend_list, get_player_bans, get_user_groups
Library	get_owned_games, get_recently_played_games, get_steam_level, get_badges
Achievements	get_player_achievements, get_global_achievement_percentages, get_game_schema, get_user_stats_for_game
Store & apps	search_store, get_app_details, get_app_reviews, get_current_players, get_news_for_app
Wishlist	get_wishlist, get_wishlist_item_count, add_to_wishlist, remove_from_wishlist

Conventions

• steam_id accepts anything. A SteamID64, a vanity name (gaben), or a full profile URL — all resolve to the same account, and resolutions are cached. Omit it entirely to use STEAM_DEFAULT_STEAM_ID.
• appid is numeric. When you only know a game's name, search_store resolves it to an app ID first.
• Responses are trimmed. Libraries, wishlists, achievements, and news are sorted, summarized, and capped by a limit so a 2,000-game library doesn't flood the context. get_app_details returns a compact projection unless you pass full: true.

Privacy and rate limits

Most account-scoped endpoints require the target profile to be public — a private "game details" setting makes get_owned_games and get_player_achievements fail or return nothing, even for your own account with a valid key. Steam applies undocumented per-method rate limits and answers with HTTP 429 when you cross one.

API references

• Endpoint reference: https://steamapi.xpaw.me/
• Steamworks Web API overview: https://partner.steamgames.com/doc/webapi_overview
• EResult codes: https://steamerrors.com/

search_store, get_app_details, and get_app_reviews use the store's public JSON endpoints, which Valve does not formally document and may change without notice.