Google Calendar MCP Server

Implementation Reference

• server.js:65-74 (handler)

  The MCP tool handler function that processes the input date, calls the helper function, and returns the result as JSON-formatted text content.

  async ({ date }) => {
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(await getMyCalendarDataByDate(date)),
        },
      ],
    };
  }

• server.js:14-56 (helper)

  Helper function implementing the core logic: fetches calendar events for the specified date using Google Calendar API, formats meetings, handles errors.

  async function getMyCalendarDataByDate(date) {
    const calendar = google.calendar({
      version: 'v3',
      auth: process.env.GOOGLE_PUBLIC_API_KEY,
    });
  
    // Calculate the start and end of the given date (UTC)
    const start = new Date(date);
    start.setUTCHours(0, 0, 0, 0);
    const end = new Date(start);
    end.setUTCDate(end.getUTCDate() + 1);
  
    try {
      const res = await calendar.events.list({
        calendarId: process.env.CALENDAR_ID,
        timeMin: start.toISOString(),
        timeMax: end.toISOString(),
        maxResults: 10,
        singleEvents: true,
        orderBy: 'startTime',
      });
  
      const events = res.data.items || [];
      const meetings = events.map((event) => {
        const start = event.start.dateTime || event.start.date;
        return `${event.summary} at ${start}`;
      });
  
      if (meetings.length > 0) {
        return {
          meetings,
        };
      } else {
        return {
          meetings: [],
        };
      }
    } catch (err) {
      return {
        error: err.message,
      };
    }
  }

• server.js:60-64 (schema)

  Zod schema for the 'date' input parameter with refinement to validate it as a parsable date string.

  date: z.string().refine(
    (val) => !isNaN(Date.parse(val)),
    {
      message: 'Invalid date format. Please provide a valid date string.',
    },

• server.js:59-76 (registration)

  Registration of the 'getMyCalendarDataByDate' tool with the MCP server, including schema and handler.

  server.tool('getMyCalendarDataByDate', {
    date: z.string().refine(
      (val) => !isNaN(Date.parse(val)),
      {
        message: 'Invalid date format. Please provide a valid date string.',
      },
      async ({ date }) => {
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(await getMyCalendarDataByDate(date)),
            },
          ],
        };
      }
    ),
  });