Failmodes

MCP server for the Fail Modes taxonomy — a machine-readable knowledge base of AI system failure modes.

Provides four tools over 100+ canonical failure mode records spanning factuality, alignment, planning, code generation, instruction following, and more.

Tools

Tool	Description
search_failure_modes	Search by symptom text or keyword phrase. Returns ranked matches.
get_failure_mode	Retrieve the full structured record for a failure mode by ID slug.
list_categories	List all taxonomy categories with descriptions and mode counts.
list_modes	List all modes, optionally filtered by category ID.

Quick Start

No installation required — run directly with npx:

npx failmodes-mcp

Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "failmodes": {
      "command": "npx",
      "args": ["-y", "failmodes-mcp"]
    }
  }
}

Cursor / VS Code

Add to your MCP settings file:

{
  "mcpServers": {
    "failmodes": {
      "command": "npx",
      "args": ["-y", "failmodes-mcp"]
    }
  }
}

Remote (no install required)

A hosted Streamable HTTP version is also available — no npm package needed:

{
  "mcpServers": {
    "failmodes": {
      "url": "https://www.failmodes.com/api/mcp"
    }
  }
}

How It Works

On first tool call, the server fetches current taxonomy data from failmodes.com and caches it in memory for the duration of the session. Requires internet access.

The stdio transport makes this compatible with any MCP client that supports running local processes (Claude Desktop, Cursor, VS Code, etc.).

Links

• Taxonomy source: github.com/elyngved/failmodes-taxonomy
• Website: failmodes.com
• Remote MCP manifest: failmodes.com/server.json

License

MIT