Connecting to a Real Service

Module 4 · Section 6 of 9

Connecting to a Real Service

Here’s the pattern from mcp-fantastical, simplified. The server calls a macOS shortcut that Fantastical exposes, parses the result, and returns formatted calendar events:

import { execSync } from "child_process";

function getEvents(startDate: string, endDate: string): string {
  try {
    const result = execSync(
      `shortcuts run "Get Calendar Events" --input-path /dev/null`,
      { encoding: "utf8" }
    );
    return parseEvents(result);
  } catch (error) {
    throw new Error(`Failed to fetch events: ${error}`);
  }
}

The key point: the server is a thin wrapper. It calls the actual service, handles errors, formats results, and returns them. The MCP layer is just the interface between that logic and Claude.