FitBit MCP

Implementation Reference

• src/server.ts:158-195 (handler)

  Handler function that fetches sleep logs from the Fitbit API for the specified date (or today), formats the response as JSON, and handles errors.

    async ({ date }) => {
      try {
        const formattedDate = formatDate(date);
        // Remove period parameter which seems to be causing issues
        const endpoint = `/user/-/sleep/date/${formattedDate}.json`;
  
        const data = await makeApiRequest(endpoint);
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  date: formattedDate,
                  sleep: data.sleep || [],
                  summary: data.summary || {},
                },
                null,
                2
              ),
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error: ${
                error instanceof Error ? error.message : String(error)
              }`,
            },
          ],
          isError: true,
        };
      }
    }
  );

• src/server.ts:152-157 (schema)

  Zod schema defining the input parameter 'date' for the getSleepLogs tool.

  {
    date: z
      .string()
      .optional()
      .describe("Date in YYYY-MM-DD format. If not specified, will use today."),
  },

• src/server.ts:149-196 (registration)

  Registration of the getSleepLogs tool using server.tool, including name, schema, and handler reference.

  // Register tool for getting sleep logs
  server.tool(
    "getSleepLogs",
    {
      date: z
        .string()
        .optional()
        .describe("Date in YYYY-MM-DD format. If not specified, will use today."),
    },
    async ({ date }) => {
      try {
        const formattedDate = formatDate(date);
        // Remove period parameter which seems to be causing issues
        const endpoint = `/user/-/sleep/date/${formattedDate}.json`;
  
        const data = await makeApiRequest(endpoint);
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  date: formattedDate,
                  sleep: data.sleep || [],
                  summary: data.summary || {},
                },
                null,
                2
              ),
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error: ${
                error instanceof Error ? error.message : String(error)
              }`,
            },
          ],
          isError: true,
        };
      }
    }
  );

• src/server.ts:68-73 (helper)

  Helper function to format or default the date to today in YYYY-MM-DD format, used in getSleepLogs handler.

  function formatDate(date?: string): string {
    if (date) return date;
    const today = new Date();
    return today.toISOString().split("T")[0]; // YYYY-MM-DD
  }

• src/server.ts:44-65 (helper)

  Helper function to make authenticated API requests to Fitbit endpoints, used by getSleepLogs and other tools.

  async function makeApiRequest(endpoint: string): Promise<any> {
    try {
      const url = `${baseUrl}${endpoint}`;
      const response = await fetch(url, {
        headers: {
          Authorization: `Bearer ${accessToken}`,
          Accept: "application/json",
        },
      });
  
      if (!response.ok) {
        throw new Error(
          `Fitbit API error: ${response.status} ${response.statusText}`
        );
      }
  
      return await response.json();
    } catch (error) {
      console.error(`Error making request to ${endpoint}:`, error);
      throw error;
    }
  }