Nostavia Wearables SDK

Welcome to the Nostavia Wearables SDK, a unified integration layer for 8+ leading wearables and health platforms.

The Nostavia Wearables SDK simplifies health and fitness data integration by providing a single, normalized API to connect with multiple wearables. It abstracts away complex provider-specific logic, handling both on-device connections and cloud-to-cloud integrations. This empowers developers to build powerful health applications without worrying about wearable fragmentation.

Key Features

• Hybrid Architecture: Interfaces directly with on-device SDKs (Apple HealthKit, Google Health Connect) and cloud APIs (Oura, WHOOP, Fitbit, etc.) via the Nostavia Backend.
• Unified Data Model: Receive normalized data across all providers (e.g., Sleep, Heart Rate, Activity, SpO2, Glucose) through a consistent, strongly-typed interface.
• Multi-Source Resolution Engine: Smartly merges and deduplicates data based on device priority (e.g., favoring Oura > Apple Watch for Sleep) while giving developers full override control.
• Real-Time Streaming: Live streaming of supported health metrics where available.
• Cross-Platform: Native support for both Flutter (Dart) and React Native (TypeScript) out of the box.

Supported Providers

The SDK harmonizes data from 8+ leading health and fitness platforms:

Provider	Architecture	Supported Data	Quirks / Notes
Apple HealthKit	On-device	Sleep, HR, HRV, SpO2, Activity, Workouts, Body, Glucose	Needs iOS permissions, queries when unlocked
Google Health Connect	On-device	Sleep, HR, SpO2, Activity, Body, Glucose	Requires Android permissions
Oura Ring	Cloud API	Sleep, Readiness, Activity, HR, HRV, Temp	Rich sleep staging. Limits: 5k requests/day
WHOOP	Cloud API	Sleep, Recovery, Strain, Workouts, HRV	Relies on proprietary physiological cycles
Fitbit / Google Health	Cloud API	Sleep, Activity, HR, SpO2, HRV	150 req/hr limit. Strict token expiration
Withings	Cloud API	Sleep, HR, BP, Weight, ECG	Strict granular scopes, custom auth flow
Polar	Cloud API	Sleep, Activity, HR, Workouts	Transaction model (requires commit after pull)
Dexcom	Cloud API	Glucose (CGM), Meals, Insulin	Polling limits. Delayed data unless medical tier

Quickstart

Get up and running with Nostavia in minutes.

React Native Integration

Install Dependencies

npm install @nostavia/react-native @nostavia/core
cd ios && pod install

Initialize the SDK

import { Nostavia } from '@nostavia/react-native';
Nostavia.init({
  apiKey: 'YOUR_NOSTAVIA_API_KEY',
  environment: 'sandbox', // or 'production'
});

Connect a Provider

import { Provider } from '@nostavia/react-native';
const connectDevice = async () => {
  try {
    await Nostavia.connect(Provider.OURA);
    console.log('Successfully connected to Oura!');
  } catch (error) {
    console.error('Connection failed:', error);
  }
};

Flutter Integration

Install Dependencies

Add to pubspec.yaml:

dependencies:
  nostavia_flutter: ^1.0.0

Run flutter pub get.

Initialize the SDK

import 'package:nostavia_flutter/nostavia_flutter.dart';
void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  
  await Nostavia.init(
    apiKey: 'YOUR_NOSTAVIA_API_KEY',
    environment: NostaviaEnvironment.sandbox,
  );
  
  runApp(MyApp());
}

Connect a Provider

Future<void> connectDevice() async {
  try {
    await Nostavia.connect(Provider.oura);
    print('Successfully connected to Oura!');
  } catch (error) {
    print('Connection failed: $error');
  }
}

API Reference

Data Fetching

Once connected, fetch normalized data across any provider using a unified API.

// Example: Fetching Sleep Data in React Native
const fetchSleepData = async () => {
  const startDate = new Date('2023-10-01T00:00:00Z');
  const endDate = new Date('2023-10-07T00:00:00Z');
  
  const sleepSessions = await Nostavia.getSleep(startDate, endDate);
  console.log(sleepSessions);
};

Core Methods

• Nostavia.getSleep(startDate, endDate): Returns Promise<Array<SleepSession>>
• Nostavia.getHeartRate(startDate, endDate): Returns Promise<Array<HeartRateSample>>
• Nostavia.getWorkouts(startDate, endDate): Returns Promise<Array<Workout>>
• Nostavia.getBloodGlucose(startDate, endDate): Returns Promise<Array<BloodGlucoseSample>>

Normalized Data Models

The SDK maps all provider-specific payloads into strict, unified models.

SleepSession

Field	Type	Description
id	String	Unique identifier.
provider	Provider	Data source (e.g., OURA, HEALTH_CONNECT).
startTime	Date	Start timestamp.
endTime	Date	End timestamp.
durationMs	Number	Total sleep duration.
efficiency	Number	Sleep efficiency score (0.0 to 1.0).
stages	Array<SleepStage>	Breakdown of AWAKE, LIGHT, DEEP, REM.

HeartRateSample

Field	Type	Description
id	String	Unique identifier.
timestamp	Date	Time of the reading.
bpm	Number	Beats per minute.
context	Enum	RESTING, ACTIVE, SLEEP, WORKOUT.

Workout

Field	Type	Description
type	String	Normalized activity type (RUNNING, CYCLING, etc.).
startTime	Date	Session start.
endTime	Date	Session end.
caloriesBurned	Number	Total active calories burned.
distanceMeters	Number	Distance covered.

System Architecture

Nostavia utilizes a robust architecture to harmonize on-device and cloud capabilities seamlessly.

Multi-Source Resolution Engine

When a user connects multiple wearables (e.g., an Oura Ring and an Apple Watch), Nostavia intelligently merges the data using a strict priority queue and deduplicates overlaps.

• Deduplication: Prevents double-counting when an external app (like Oura) writes to Apple HealthKit.
• Smart Priority: Leverages the best device for specific metrics (e.g., Oura for Sleep, Apple Watch for Heart Rate).
• Overrides: Fully customizable via Nostavia.setSourcePriority(DataType, [Providers]).