mcp-fitbit/build/utils.js

Model Context Protocol (MCP) server for accessing Fitbit health and fitness data. Connect AI assistants like Claude to your Fitbit data for personalized health insights.

/**
 * Shared utility functions for Fitbit API integration
 */
import { z } from 'zod';
import { HTTP_CONFIG, ERROR_MESSAGES, FITBIT_API_VERSIONS, DATE_REGEX, VALIDATION_MESSAGES, TIME_PERIODS, HEART_RATE_DETAIL_LEVELS } from './config.js';
/**
 * Makes a generic request to the Fitbit API.
 * Handles adding the base URL, authorization header, and basic error handling.
 * @param endpoint The specific API endpoint path (e.g., '/body/weight/date/today/30d.json').
 * @param getAccessTokenFn A function that returns the current valid access token or null.
 * @param apiBase The base URL for the API (defaults to v1, can be overridden for different API versions)
 * @returns A promise resolving to the parsed JSON response (type T) or null if the request fails.
 */
export async function makeFitbitRequest(endpoint, getAccessTokenFn, apiBase = FITBIT_API_VERSIONS.V1) {
    const currentAccessToken = await getAccessTokenFn();
    if (!currentAccessToken) {
        console.error(`Error: ${ERROR_MESSAGES.NO_ACCESS_TOKEN}`);
        return null;
    }
    // Ensure endpoint starts correctly relative to the user path
    const cleanEndpoint = endpoint.startsWith('/')
        ? endpoint.substring(1)
        : endpoint;
    // Construct the full URL including the user scope '-'.
    const url = `${apiBase}/user/-/${cleanEndpoint}`;
    console.error(`Attempting Fitbit API request to: ${url}`);
    const headers = {
        'User-Agent': HTTP_CONFIG.USER_AGENT,
        Authorization: `Bearer ${currentAccessToken}`,
        Accept: 'application/json',
    };
    try {
        const response = await fetch(url, { headers });
        if (!response.ok) {
            const errorBody = await response.text();
            console.error(`Fitbit API Error! Status: ${response.status}, URL: ${url}, Body: ${errorBody}`);
            if (response.status === 401) {
                console.error(ERROR_MESSAGES.TOKEN_EXPIRED);
            }
            return null;
        }
        // Handle potential empty response body for certain success statuses (e.g., 204 No Content)
        if (response.status === 204) {
            return {}; // Return an empty object or appropriate type for no content
        }
        return (await response.json());
    }
    catch (error) {
        console.error(`Error making Fitbit request to ${url}:`, error);
        return null;
    }
}
// === Parameter Validation Schemas ===
export const CommonSchemas = {
    period: z
        .enum(TIME_PERIODS)
        .describe(VALIDATION_MESSAGES.PERIOD_REQUIRED),
    startDate: z
        .string()
        .regex(DATE_REGEX, VALIDATION_MESSAGES.DATE_FORMAT)
        .describe(VALIDATION_MESSAGES.START_DATE_REQUIRED),
    endDate: z
        .string()
        .regex(DATE_REGEX, VALIDATION_MESSAGES.DATE_FORMAT)
        .describe(VALIDATION_MESSAGES.END_DATE_REQUIRED),
    detailLevel: z
        .enum(HEART_RATE_DETAIL_LEVELS)
        .describe(VALIDATION_MESSAGES.DETAIL_LEVEL_REQUIRED),
    date: z
        .string()
        .regex(DATE_REGEX, VALIDATION_MESSAGES.DATE_FORMAT)
        .describe('The date for which to retrieve data (YYYY-MM-DD)'),
    afterDate: z
        .string()
        .regex(DATE_REGEX, VALIDATION_MESSAGES.DATE_FORMAT)
        .describe('Retrieve activities after this date (YYYY-MM-DD)'),
    limit: z
        .number()
        .min(1)
        .max(100)
        .optional()
        .describe('Maximum number of items to return (1-100, default: 20)')
};
// === Tool Response Helpers ===
export function createErrorResponse(message) {
    return {
        content: [{ type: 'text', text: message }],
        isError: true,
    };
}
export function createSuccessResponse(data) {
    const rawJsonResponse = JSON.stringify(data, null, 2);
    return {
        content: [{ type: 'text', text: rawJsonResponse }],
    };
}
export function createNoDataResponse(context) {
    return {
        content: [{ type: 'text', text: `${ERROR_MESSAGES.NO_DATA_FOUND} ${context}.` }],
    };
}
export function registerTool(server, config) {
    server.tool(config.name, config.description, config.parametersSchema, config.handler);
}
// === Fitbit-Specific Tool Helpers ===
export async function handleFitbitApiCall(endpoint, params, getAccessTokenFn, options = {}) {
    const { apiBase = FITBIT_API_VERSIONS.V1, successDataExtractor, noDataMessage, errorContext = JSON.stringify(params) } = options;
    const responseData = await makeFitbitRequest(endpoint, getAccessTokenFn, apiBase);
    if (!responseData) {
        return createErrorResponse(`${ERROR_MESSAGES.API_REQUEST_FAILED} for ${errorContext}. ${ERROR_MESSAGES.CHECK_TOKEN_PERMISSIONS}.`);
    }
    // Check for empty data if extractor provided
    if (successDataExtractor) {
        const extractedData = successDataExtractor(responseData);
        if (!extractedData || extractedData.length === 0) {
            return createNoDataResponse(noDataMessage || errorContext);
        }
    }
    return createSuccessResponse(responseData);
}