valkyrie-mom

valkyrie-mom-mcp

MCP (Model Context Protocol) server and Claude Code plugin for AI-assisted Mansions of Madness 2nd Edition scenario creation with Valkyrie.

What it does

This server exposes Valkyrie scenario editing as MCP tools, enabling AI assistants (Claude, etc.) to create, modify, validate, and build complete MoM scenarios. It auto-detects the Valkyrie editor directory so scenarios appear directly in the app.

The plugin bundles 7 skills covering advanced patterns (event loops, mythos scaling, tile placement chains, custom puzzles, etc.) and an autonomous scenario designer agent.

Install

As a Claude Code plugin (recommended)

claude plugin marketplace add thijs-hakkenberg/ValkyrieMCP
claude plugin install valkyrie-mom

This gives you:

• MCP server with 20 tools for scenario editing (auto-started)
• 7 skills: /scenario, /event-patterns, /tile-placement, /variables-and-mythos, /custom-monsters, /ui-and-puzzles, /items-and-distribution
• Scenario designer agent for autonomous scenario creation
• 5 MCP resources for format documentation

To update to the latest version:

claude plugin marketplace update valkyrie-mom
claude plugin update valkyrie-mom

To uninstall:

claude plugin uninstall valkyrie-mom

As a standalone MCP server (Claude Desktop, other MCP clients)

Add to your MCP client config (e.g., ~/.claude/mcp.json or Claude Desktop settings):

{
  "mcpServers": {
    "valkyrie-mom": {
      "command": "npx",
      "args": ["-y", "@thijshakkenberg/valkyrie-mom-mcp"]
    }
  }
}

This gives you the MCP tools and resources, but not the skills or agent (those require Claude Code).

From source

git clone https://github.com/thijs-hakkenberg/ValkyrieMCP.git
cd ValkyrieMCP
npm install
npx tsx src/index.ts   # Run MCP server via stdio

Skills

Skill	Description
/scenario	Guided end-to-end scenario creation workflow
/event-patterns	Event loops, multi-question dialogues, silent events, token swaps, random events, variable branching
/tile-placement	Standard placement chains, multi-entry tiles, naming conventions
/variables-and-mythos	Variable system, mythos scaling formula, random generation, hero detection, content pack gating
/custom-monsters	Custom activations, evade/horror events, round-based spawn triggering
/ui-and-puzzles	Prologues, interactive journals, combination locks, built-in puzzle types
/items-and-distribution	Random items, unique items, starting items, inspection events

MCP Tools

Lifecycle

Tool	Description
list_scenarios	List all scenarios in the Valkyrie editor directory
create_scenario	Create a new scenario (defaults to Valkyrie editor dir)
load_scenario	Load an existing scenario from a directory
get_scenario_state	Get current scenario component/localization summary
validate_scenario	Run all validation rules
build_scenario	Save and build .valkyrie package

Components

Tool	Description
upsert_event	Create or update an event
upsert_tile	Create or update a tile
upsert_token	Create or update a token
upsert_spawn	Create or update a monster spawn
upsert_item	Create or update an item
upsert_puzzle	Create or update a puzzle
upsert_ui	Create or update a UI element
delete_component	Delete a component with cascade reference cleanup
set_localization	Set localization key-value pairs

Map

Tool	Description
get_map_ascii	Render tile layout as ASCII art
suggest_tile_layout	Suggest coordinates for linear, L-shape, or hub-spoke layouts
place_tile_relative	Compute position relative to an existing tile

Reference

Tool	Description
search_game_content	Search game content catalogs (846 entries across tiles, monsters, items, audio)

Diagnostics

Tool	Description
export_bug_report	Generate a ZIP bug report with session trace, scenario files, validation results, and Valkyrie logs

MCP Resources

Resource	URI
Event format docs	valkyrie://format/events
Localization format docs	valkyrie://format/localization
Component format docs	valkyrie://format/components
Pattern reference	valkyrie://format/patterns
Current scenario state	valkyrie://scenario/current

MCP Prompts

Prompt	Description
create-scenario	Guided workflow for creating a new scenario
review-scenario	Analyze a scenario for balance and completeness