FitBit MCP

Implementation Reference

• src/server.ts:388-423 (handler)

  The handler function for the getFoodLogs tool. It uses formatDate to prepare the date, calls makeApiRequest to fetch food logs from the Fitbit API endpoint `/user/-/foods/log/date/{date}.json`, formats the response with meals and summary, and returns it as MCP content or an error response.

  async ({ date }) => {
    try {
      const formattedDate = formatDate(date);
      const endpoint = `/user/-/foods/log/date/${formattedDate}.json`;
  
      const data = await makeApiRequest(endpoint);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify(
              {
                date: formattedDate,
                meals: data.foods || [],
                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:382-387 (schema)

  Zod input schema for the getFoodLogs tool, defining an optional 'date' string parameter.

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

• src/server.ts:380-424 (registration)

  Registration of the getFoodLogs tool on the MCP server instance using server.tool(name, schema, handler).

  server.tool(
    "getFoodLogs",
    {
      date: z
        .string()
        .optional()
        .describe("Date in YYYY-MM-DD format. If not specified, will use today."),
    },
    async ({ date }) => {
      try {
        const formattedDate = formatDate(date);
        const endpoint = `/user/-/foods/log/date/${formattedDate}.json`;
  
        const data = await makeApiRequest(endpoint);
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  date: formattedDate,
                  meals: data.foods || [],
                  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:44-65 (helper)

  Helper function makeApiRequest used by the getFoodLogs handler to perform authenticated GET requests to the Fitbit API.

  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;
    }
  }

• src/server.ts:68-72 (helper)

  Helper function formatDate used by the getFoodLogs handler to normalize the date parameter or default to today.

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