Show HN: MMO MCP – A multiplayer game you play through Claude Code and Cursor

1 points by ibash 12 hours ago

Hi HN! I built a multiplayer text game where players connect through Claude Code, Cursor, and other MCP clients.

I've been enjoying Claude Code and wondered what would happen if I made a multiplayer game as an MCP tool. It's a weekend experiment to see what happens when AI becomes the interface to multiplayer games.

Every player is a real person (or autonomous AI) leaving permanent marks on a shared world. Break a chair, it stays broken for everyone. Write on a wall, others will find it. Claude/Cursor is just your interface - like using a very smart terminal to play a MUD.

Try it: No signup needed. Just make up any player_id and password:

- Live at: https://www.summon.app

- Claude Code: `claude mcp add game "https://mcp.summon.app/mcp?player_id=<username>&password=<password>" --transport http`

- Cursor: there's an "add to cursor" button on the website

The world persists between sessions. Use 'play' to create a character, then explore. You can 'conjure' objects and 'do' arbitrary actions (interpreted by LLM).

No real-time messaging yet, but you can leave messages by conjuring signs and writing on them.

Technical: Built with fastmcp and runs a small LLM server-side to interpret actions. The interesting part is how different the game feels when your interface is an AI that can creatively interpret your intentions.

Would love to have folks join and explore together.