FoundryVTT MCP Server

A Model Context Protocol (MCP) server that integrates with FoundryVTT, allowing AI assistants to interact with your tabletop gaming sessions through natural language.

Features

• Dice Rolling — standard RPG notation with any formula
• Data Querying — search and inspect actors, items, scenes, journals
• Game State — combat tracking, chat messages, user presence
• Content Generation — NPCs, loot tables, rule lookups
• World Search — full-text search across all game entities
• Live Connection — Socket.IO loads complete world state on connect
• MCP Resources — foundry:// URIs for direct data access
• Diagnostics — optional server health monitoring (requires REST API module)

Quick Start

Prerequisites

• Node.js 18+ (or Bun)
• FoundryVTT server running with an active world
• MCP-compatible AI client (Claude Desktop, Claude Code, VS Code, etc.)

Recommended: Create a Dedicated API User

It is recommended to create a separate FoundryVTT user account for the MCP server rather than using your own GM or player account. This provides better security and auditability.

In FoundryVTT:

1. Go to Configuration → User Management
2. Click Create User
3. Set a username (e.g., mcp-api) and a strong password
4. Assign the Assistant GM role (needed to read world data and roll dice)
5. Use this account's credentials in your MCP configuration

Benefits:

• Chat messages and actions from the MCP server are clearly attributed to a separate user
• You can revoke access by disabling the API user without affecting your own account
• Limits blast radius if credentials are ever exposed

Installation

Run directly without installing — no clone needed:

bunx foundryvtt-mcp
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Or with npx:

npx -y foundryvtt-mcp
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Client Configuration

Claude Desktop / Claude Code

Add to your MCP configuration (claude_desktop_config.json or .mcp.json):

{
  "mcpServers": {
    "foundryvtt": {
      "command": "bunx",
      "args": ["foundryvtt-mcp"],
      "env": {
        "FOUNDRY_URL": "http://localhost:30000",
        "FOUNDRY_USERNAME": "your_username",
        "FOUNDRY_PASSWORD": "your_password"
      }
    }
  }
}
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VS Code

Add to your VS Code MCP settings:

{
  "servers": {
    "foundryvtt": {
      "command": "bunx",
      "args": ["foundryvtt-mcp"],
      "env": {
        "FOUNDRY_URL": "http://localhost:30000",
        "FOUNDRY_USERNAME": "your_username",
        "FOUNDRY_PASSWORD": "your_password"
      }
    }
  }
}
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Development Setup

For local development or contributing:

git clone https://github.com/laurigates/foundryvtt-mcp.git
cd foundryvtt-mcp
bun install
bun run setup-wizard
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The setup wizard will detect your FoundryVTT server, test connectivity, and generate your .env configuration.

To configure manually, see the Configuration Guide.

Environment Variables

Variable	Required	Description
FOUNDRY_URL	Yes	FoundryVTT server URL (e.g., http://localhost:30000)
FOUNDRY_USERNAME	Yes	FoundryVTT user account
FOUNDRY_PASSWORD	Yes	FoundryVTT user password
FOUNDRY_USER_ID	No	Bypass username-to-ID resolution
FOUNDRY_API_KEY	No	REST API module key (enables diagnostics tools)
FOUNDRY_WRITE_ENABLED	No	Enable game-state mutations — true required for the write tools (default: false)
LOG_LEVEL	No	debug, info, warn, or error (default: info)
FOUNDRY_TIMEOUT	No	Request timeout in ms (default: 10000)

Usage

Ask your AI assistant things like:

• "Roll 1d20+5 for an attack roll"
• "Show me all the NPCs in this scene"
• "What's the current combat initiative order?"
• "Search the world for anything related to dragons"
• "Generate a random NPC merchant"

Available Tools

Data Access

• search_actors — find characters, NPCs, monsters
• get_actor_details — detailed character information
• search_items — find equipment, spells, consumables
• get_scene_info — current scene details
• search_journals — search notes and handouts
• get_journal — retrieve a specific journal entry
• get_users — list users, roles, and live online status
• get_combat_state — combat state and initiative order
• get_chat_messages — recent chat history

Write Operations (require FOUNDRY_WRITE_ENABLED=true)

Game-state mutations are disabled by default. They use the Socket.IO modifyDocument protocol over an authenticated session, and the connected user needs GM/owner permission. Set FOUNDRY_WRITE_ENABLED=true to enable them.

• start_combat — begin a new encounter, seeding combatants from tokens (does not check for an existing combat — calling it during an active one creates a second encounter)
• next_turn — advance the active combat to the next turn (wraps to the next round)
• end_combat — end (delete) the active combat encounter
• set_initiative — set a combatant's initiative in the active combat, moving the turn marker with the acting combatant if the reorder shifts them
• move_token — move a token to new x/y coordinates on its scene
• apply_status_effect — apply or remove a status condition (e.g. prone, stunned) on a token's actor
• update_actor_attributes — patch an actor's system attributes (HP, currency, spell slots, …)
• create_actor_item — add an inline item to an actor
• update_actor_item — apply a JSON merge patch to an actor's item
• delete_actor_item — remove an item from an actor
• create_journal_entry — create a journal entry with one or more text pages (GM-only by default; pass visibility to let players read it)

World

• search_world — full-text search across all game entities
• get_world_summary — overview of the current world state
• refresh_world_data — reload world data from FoundryVTT; needed after a dropped connection, whose missed updates are never replayed into the cache

Game Mechanics

• roll_dice — roll dice; dice terms (NdS) and whole numbers joined by +/-, with unsupported notation (4d6kh3, 1d20r1, *) rejected rather than dropped. Parentheses are the one transport difference: FoundryVTT evaluates them when FOUNDRY_API_KEY is set, the local roller rejects them otherwise
• lookup_rule — stub: returns a templated placeholder, consults no rules source

Content Generation

• generate_npc — generate NPC text (not written to the world)
• generate_loot — generate treasure text for a level (not written to the world)

Diagnostics (requires REST API module)

• get_recent_logs — retrieve filtered FoundryVTT logs
• search_logs — search logs by pattern, listing the matching entries
• get_system_health — server health status with versions, user/module counts, memory and log error counts (no CPU or disk metrics)
• diagnose_errors — stub: returns a fixed "no errors detected" summary
• get_health_status — comprehensive health diagnostics; flags the world snapshot when the cache has stopped following live changes

Available Resources

• foundry://actors — all actors in the world
• foundry://items — all items in the world
• foundry://scenes — all scenes
• foundry://scenes/current — current active scene
• foundry://journals — all journal entries
• foundry://users — online users
• foundry://combat — active combat state; combatants are in initiative order, so combat.turn indexes them directly
• foundry://world/settings — world and campaign settings
• foundry://system/diagnostics — system diagnostics (requires REST API module)

Troubleshooting

The connectivity and setup helpers ship in the source tree (not the published bin), so run them from a dev checkout:

git clone https://github.com/laurigates/foundryvtt-mcp.git
cd foundryvtt-mcp && bun install
bun run test-connection   # Probe FoundryVTT connectivity
bun run setup-wizard      # Re-run interactive setup
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Detailed guide: TROUBLESHOOTING.md

Development

bun run build          # Compile TypeScript and make dist/index.js executable
bun run dev            # Development mode with hot reload
bun test               # Unit tests (Vitest)
bun run test:e2e       # E2E tests (Playwright)
bun run lint           # Lint code (Biome)
bun run smoke          # Startup smoke test against the local build
bun run smoke:pack     # Pack-and-install smoke test (mirrors what npx consumers get)
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See Development Guide for project structure, adding tools, testing, and building.

Roadmap

See Feature Tracker for completed and planned features.

Contributing

See CONTRIBUTING.md.

License

MIT License — see LICENSE for details.

Support

• Issues: GitHub Issues
• Discord: FoundryVTT Discord #api-development
• Docs: FoundryVTT API

Acknowledgments

• FoundryVTT team for the excellent VTT platform
• Anthropic for the Model Context Protocol
• The tabletop gaming community for inspiration and feedback