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What is Synheart Wear?

Synheart Wear is a unified wearable SDK ecosystem that streams biometric data (HR, HRV, steps, calories, distance) from Apple Watch, Fitbit, Garmin, Whoop, and Samsung devices through a single, standardized API across Flutter, Android, and iOS applications.
Wondering what data you actually get from each device — and what you don’t? Wearable signals is the reality check: the access gates, the raw signals, and what the data becomes downstream.

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Key Features

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Cross-Platform Support

  • Flutter: Cross-platform mobile apps (iOS 13+ / Android API 21+)
  • Native Android: Kotlin SDK with Health Connect integration (Android API 21+; target SDK 34+)
  • Native iOS: Swift SDK with HealthKit integration (iOS 13.0+)

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Multi-Device Support

DeviceFlutterAndroidiOSStatus
Apple Watch✅—✅ (via HealthKit)Ready
Health Connect✅✅ (Native)❌Ready
WHOOP✅✅✅Ready
BLE Heart Rate Monitors✅✅✅Ready
Fitbit (Cloud OAuth)✅✅✅Ready
Garmin (Cloud)✅✅✅Ready
Garmin (Native RTS)✅✅✅On demand (licensed)
Samsung Health📋📋❌Planned
Oura Ring (Cloud OAuth)✅✅✅Ready
Garmin Native RTS: The Garmin Health SDK Real-Time Streaming (RTS) capability requires a separate license from Garmin. The GarminHealth facade is available on demand for licensed integrations. The underlying Garmin Health SDK code is proprietary to Garmin and is not distributed as open source. For cloud-based Garmin data (OAuth + webhooks), use GarminProvider.
Legend: ✅ Ready | 📋 Planned

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BLE Heart Rate Monitor Support

Direct Bluetooth LE connection to any standard heart rate monitor — no cloud API required. Works with devices implementing the standard BLE Heart Rate Profile (0x180D), including:
  • WHOOP (Broadcast Heart Rate mode)
  • Polar chest straps (H10, OH1)
  • Wahoo TICKR
  • Garmin HRM-Pro / HRM-Dual

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Unified data shape

All platform SDKs (synheart_wear, synheart-wear-kotlin, synheart-wear-swift) emit the same JSON shape from WearMetrics.toJson(): 
{
  "timestamp": "2025-10-20T18:30:00Z",
  "device_id": "applewatch_1234",
  "source": "apple_healthkit",
  "metrics": {
    "hr": 72,
    "hrv_rmssd": 45,
    "hrv_sdnn": 62,
    "steps": 1045,
    "calories": 120.4,
    "distance": 2.5
  },
  "meta": {
    "battery": 0.82
  },
  "rr_ms": [800, 850, 820]
}
timestamp, device_id, source, metrics, and meta are required. metrics keys are scoped by the MetricType enum (hr, hrv_rmssd, hrv_sdnn, steps, calories, distance, stress); adapters set the keys they actually have. meta is a free-form Map<String, Object?> — only meta.battery is read back by the SDK (via WearMetrics.batteryLevel).

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Privacy & security

  • Consent-first design — every adapter call is gated by explicit consent grants; revoking consent stops collection immediately.
  • Local-data encryption — LocalCache uses AES-256-CBC when enableEncryption is set on SynheartWearConfig.
  • No persistent IDs — the SDK does not generate or persist a user-level identifier; integrations supply their own pseudonymous ID.
  • Right to revoke — revokeConsent() clears active permissions and the local cache.

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Architecture

┌──────────────────────────────────────────────────────┐
│              Synheart Wear Ecosystem                 │
└──────────────────────────────────────────────────────┘
                         │
        ┌────────────────┼────────────────┐
        │                │                │
┌───────▼────────┐ ┌─────▼─────┐ ┌───────▼────────┐
│ synheart-wear- │ │synheart-  │ │ synheart-wear- │
│    flutter     │ │wear-kotlin│ │     swift      │
│  (Flutter)     │ │ (Android) │ │     (iOS)      │
└────────────────┘ └───────────┘ └────────────────┘

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SDK Architecture

Each SDK implements a consistent architecture: 
┌─────────────────────────┐
│   synheart_wear SDK     │
├─────────────────────────┤
│ Device Adapters Layer   │
│ (Apple, Fitbit, etc.)   │
├─────────────────────────┤
│ Normalization Engine    │
│ (standard output schema)│
├─────────────────────────┤
│   Local Cache & Storage │
│   (encrypted, offline)  │
└─────────────────────────┘

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Available SDKs

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Flutter SDK

Cross-platform SDK for iOS and Android apps.

Flutter SDK Documentation

Complete guide for Flutter integration
Installation: 
dependencies:
  synheart_wear: ^0.3.1
Repository: synheart-wear-flutter · runnable example

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Android (Kotlin) SDK

Native Android SDK with Health Connect integration.

Kotlin SDK Documentation

Complete guide for Android integration
Installation: 
implementation("com.github.synheart-ai:synheart-wear-kotlin:0.3.0")
Repository: synheart-wear-kotlin

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iOS (Swift) SDK

Native iOS SDK with HealthKit integration.

Swift SDK Documentation

Complete guide for iOS integration
Installation: 
.package(url: "https://github.com/synheart-ai/synheart-wear-swift.git", from: "0.2.0")
Repository: synheart-wear-swift

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Stability

Synheart Wear is pre-1.0. Minor version bumps may include breaking API changes — pin exact versions (or a tight constraint like ^0.3.0) in production, and read each SDK’s CHANGELOG before upgrading. Individual wearable adapters are versioned independently of the SDK; adapter-specific changes are called out in the Adapters page.

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Use Cases

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Wellness Apps

Monitor heart rate, HRV, and activity metrics for wellness coaching: 
final synheart = SynheartWear(
  config: SynheartWearConfig.withAdapters({
    DeviceAdapter.platformHealth,
  }),
);

synheart.streamHR(interval: Duration(seconds: 5))
  .listen((metrics) {
    final hr = metrics.getMetric(MetricType.hr);
    if (hr != null && hr > 120) {
      showAlert('High heart rate detected!');
    }
  });

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Mental Health Platforms

Stream biosignals into Synheart Core for HSI fusion (focus, capacity, recovery, strain): 
synheart.streamHRV(windowSize: Duration(seconds: 60))
  .listen((metrics) {
    // Forward to Synheart Core for on-device HSI computation
  });

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Research Applications

Collect biometric data for scientific studies: 
final synheart = SynheartWear(
  config: SynheartWearConfig(
    enableLocalCaching: true,
    enableEncryption: true,
  ),
);

final whoopProvider = WhoopProvider(
  appId: 'your-app-id',
  userId: 'user-123',
);

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Next Steps

Quick Start

Get started in 5 minutes

Flutter SDK

Flutter integration guide

Kotlin SDK

Android integration guide

Swift SDK

iOS integration guide

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Community

  • GitHub: github.com/synheart-ai — every Wear SDK lives in its per-language repo (synheart-wear-flutter, synheart-wear-kotlin, synheart-wear-swift).
  • Issues: file against the relevant per-language repo.