# failmodes-mcp

MCP server for the [Fail Modes](https://www.failmodes.com) 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`:

```bash
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):

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

### Cursor / VS Code

Add to your MCP settings file:

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

### Remote (no install required)

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

```json
{
  "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](https://www.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](https://github.com/elyngved/failmodes-taxonomy)
- Website: [failmodes.com](https://www.failmodes.com)
- Remote MCP manifest: [failmodes.com/server.json](https://www.failmodes.com/server.json)

## License

MIT