"Services or tools available for free without requiring an API key" matching MCP servers:

An MCP server that enables interaction with Google Cloud Game Services API, allowing users to manage game server deployments, realms, and configurations through natural language.

A read-only MCP server that reports free games on Epic Games Store and GOG.com using public endpoints, without requiring any account or credentials.

An MCP server that lets Claude control a Minecraft bot with 40+ actions including movement, combat, crafting, and inventory management. Built on Mineflayer, it supports Microsoft authentication, pathfinding, and auto-reconnect.

A Multi-Agent Conversation Protocol server for interacting with Google Play Game Services Configuration API, allowing management of game configurations through natural language commands.

Enables AI assistants to interact with AccelByte Gaming Services APIs through semantic search, detailed API information retrieval, and authenticated API execution for game backend operations.

Wraps the Manifold Markets public REST API into an MCP server, providing 40 tools for querying markets, users, groups, bets, comments, and more.

Enables AI assistants to read, author, and edit Skyrim Special Edition plugins, including NPCs, quests, dialogue, books, items, cells, face data, and Papyrus scripts, with validation, snapshots, and packaging tools.

Enables MCP-compatible AI clients to inspect Godot project and editor state, observe opted-in running scenes, manage processes, and apply permission-scoped guarded edits. It starts read-only and exposes additional capabilities only through explicit command-line flags.

Provides Steam concurrent player trends as JSON, offering monthly player time series, growth rates across 3M/6M/12M/5Y windows, and live most-played feeds via a single REST endpoint, without needing a Steam Web API key.

A source-preserving MCP server for coding agents working on Hearts of Iron IV mods, combining focus tree, GUI, and map tools with transaction safety.

An MCP server that wraps the ThreeHats Foundry VTT REST API relay so an LLM agent can author and manage Foundry VTT content, primarily creating D&D 5e creatures, through native MCP tools.

Diablo II Resurrected modding toolkit — character builder, mod build/deploy pipeline, save inspector, CASC reader, and MCP server for Claude/Codex/AI integration. Linux/Steam Deck.

Control Unity Editor from AI agents. 200+ MCP tools for GameObjects, Scenes, Assets, Materials, Prefabs, Terrain, Physics, Lighting, and more. Works with Claude, Cursor, Windsurf, VS Code Copilot — any MCP client. Zero config: just npx and go.

Enables preparing Foundry worlds and running encounters through the FoundryVTT REST API Relay, with tools for managing worlds, scenes, encounters, and table play.

Enables inspection of local SudokuPad replay files by exposing read-only tools that return replay metadata, filtered and paginated event timelines with undo/redo links, and full reconstructed grid states at a given action or time.

MCP server for the Cocofolia TRPG tool that enables character generation, NPC batch creation, session analysis, random events, and rule assistance via natural language.

Enables Claude to interact with the RuneScape Wiki through search, page retrieval, extracts, and ASCII image rendering.

An MCP server that gives AI coding assistants access to the World of Warcraft addon API documentation, FrameXML/AddOn UI source code, and the Warcraft Wiki across all four client flavors.

Enables a bot to inspect, query, create, edit, and script Roblox Studio instances in token-cheap batches, plus run Luau, playtests, screenshots, and inputs through Roblox's official Studio MCP connection. It runs locally over stdio or an authenticated local HTTP endpoint, returning small structured answers instead of dumping whole games into context.

Enables AI assistants to build and manage Unity projects directly through the Unity Editor, providing 150+ tools for scene creation, script generation, play mode control, input simulation, and performance analysis.

Connect to your TTRPG campaign's repository and database. Instead of retrieving prose, its 48 tools (20 read, 28 write) return typed state: 14 entity schemas (NPCs, factions, locations, sessions, lore), relationship and knowledge-graph queries, wiki blocks, and a narrative-state bundle of open threads and canon facts.

An intelligent game assistant for Red Alert, based on LangGraph and MCP, providing asynchronous architecture and multimodal AI control for game strategy, production, and combat management.

Exposes read-only tools for searching players, fetching profiles, live matches, match history, stats, leaderboards, heroes, team-ups, insights, matches, and factions from Marvel Rivals public data. It also returns an MCP-UI player dashboard rendering rank, competitive record, live match rosters, hero win rates, and recent match form, over local stdio or Streamable HTTP.

Enables a player to investigate and solve a voice-only murder mystery through an MCP client by searching locations, examining evidence, questioning suspects, reviewing notes, and making a confirmed accusation. The AI assistant never receives the solution before a valid accusation is committed.

Live PC game key prices: the lowest listed price for a game across official stores and key stores (by name, Steam app ID or Steam URL, or up to 50 games at once), with a link to the full comparison.

Enables an LLM agent to play a melee match against the game's built-in AI by exposing raw wc3env orders as MCP tools, with games graded and native replays saved.

Identify trading cards (Pokémon, One Piece, Lorcana, Yu-Gi-Oh!, Magic, Star Wars: Unlimited) and football cards from a photo, several cards per photo, with Cardmarket prices. Search and correct cards and export them as CSV or JSON; works with a free demo key, your own API key is optional.

Provides access to comprehensive Riot Games API documentation for League of Legends, Teamfight Tactics, Valorant, and Legends of Runeterra, including endpoint details, parameters, and response formats.

Enables ChatGPT to retrieve live Pokémon data from PokéAPI, build tournament squads, and list popular tournament picks through MCP tools.

Enables solving crossword puzzles by loading grid and clue files, registering candidate words, checking consistency, and rendering final solutions. Supports Japanese crosswords with automated solving capabilities through natural language interaction.