@numeratica/mcp

A thin MCP bridge that connects any MCP client (Claude Desktop, Cursor, …) to the Numeratica financial-planning API — retirement Monte Carlo, taxes, RMDs, Social Security, Roth conversions, and more.

Get a free key at https://docs.numeratica.com.

How it works

This package is a transport bridge, nothing more. It reads JSON-RPC from stdin and forwards each message to the hosted POST /mcp endpoint with your API key as a bearer token, then writes the response back to stdout. The tool list and all results come straight from the API — so the bridge always stays in sync and ships no calculation logic of its own. Your key is sent only in the Authorization header and is never logged.

• Zero runtime dependencies (Node ≥ 18 built-in fetch + node:readline).
• Open source (MIT). The interesting part is the API; this is just the wire.

Install

No install needed — your MCP client runs it on demand with npx. (You can also npm i -g @numeratica/mcp to get the numeratica-mcp command.)

Claude Desktop

Add to claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "numeratica": {
      "command": "npx",
      "args": ["-y", "@numeratica/mcp"],
      "env": { "NUMERATICA_API_KEY": "nmr_sk_your_key_here" }
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json (or a project .cursor/mcp.json):

{
  "mcpServers": {
    "numeratica": {
      "command": "npx",
      "args": ["-y", "@numeratica/mcp"],
      "env": { "NUMERATICA_API_KEY": "nmr_sk_your_key_here" }
    }
  }
}

Restart the client and the Numeratica tools appear. Try: "Run a retirement Monte Carlo for a 40-year-old retiring at 65."

Configuration

Variable	Required	Default	Notes
NUMERATICA_API_KEY	yes	—	Your key. Get one free at docs.numeratica.com. Never logged.
NUMERATICA_BASE_URL	no	https://api.numeratica.com	Override the API base (e.g. for testing).

You can also pass the key with --key <value> instead of the env var.

Links

• API docs & reference: https://docs.numeratica.com
• Get a free key: https://docs.numeratica.com/get-key

License

MIT © Numeratica / Francis Townsend-Merino