@mythxengine/mcp-server

A Model Context Protocol (MCP) server for tabletop RPG game mechanics: dice rolling with five-tier outcomes and position/effect framing, FitD-style stress (push / resist / flashback), combat tracking, situation clocks, leads and investigations, NPC relationships, world generation, and session persistence — 100+ tools, plus four complete bundled starter worlds that import on first run.

Requirements

• Node.js >= 22.13 (uses the builtin node:sqlite; Bun also works via bun:sqlite)

Install

# Claude Code
claude mcp add rpg -- npx -y @mythxengine/mcp-server

Or configure any MCP client to run it over stdio:

{
  "mcpServers": {
    "rpg": {
      "command": "npx",
      "args": ["-y", "@mythxengine/mcp-server"]
    }
  }
}

Data directory

Session state and world packs live in a SQLite database. Resolution order:

1. RPG_MCP_DATA_DIR env var (explicit override)
2. <repo>/data when running from a development checkout
3. ~/.mythxengine/data (installed / npx runs)

Bundled worlds

Four starter world packs (Port Miriam, Aethelgard, Threshold Deep, Treehouse Anthology) ship in the package and are imported into your database on first startup — existing packs are never overwritten. Explore them with list_world_packs / load_world_summary.

License

MIT