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The Consent Module manages user permissions and enforces privacy boundaries across all Synheart Core modules.

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Core Principles

  1. Explicit Consent: All data collection requires explicit user consent
  2. Granular Control: Users control each module independently
  3. Revocable: Consent can be withdrawn at any time
  4. Enforced: Missing consent = no data collection, not synthetic data
  5. Transparent: Users see exactly what each module collects
Synheart Core defines the following consent types:

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Module-Level Consents

Consent TypeModuleWhat It EnablesDefault
biosignalsWear ModuleHR, HRV, sleep, motion from wearablesfalse
phoneContextPhone ModuleDevice motion, screen state, app contextfalse
behaviorBehavior ModuleTaps, scrolls, typing cadencefalse
cloudUploadCloud ConnectorUpload derived HSI to cloudfalse

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Interpretation Module Consents

Consent TypeModuleWhat It EnablesDefault
focusEstimationSynheart FocusFocus score computationfalse
emotionEstimationSynheart EmotionEmotion/stress inferencefalse
When the SDK initializes, it checks for existing consent. If no consent exists, the SDK:
  1. Returns empty/null state until consent is granted
  2. Provides consent request callbacks to the app
  3. Does NOT collect any data
Example: 
await Synheart.initialize(
  userId: 'anon_user_123',
  config: SynheartConfig(
    enableWear: true,  // Requests consent, does not auto-enable
    enablePhone: true,
    enableBehavior: true,
  ),
);

// SDK checks consent status
bool hasConsent = await Synheart.hasConsent('biosignals');

if (!hasConsent) {
  // App shows consent UI
  bool granted = await showConsentDialog('biosignals');

  if (granted) {
    await Synheart.grantConsent('biosignals');
  }
}
Consent preferences are stored:
  • Locally: On-device encrypted storage
  • Not synced: Consent is device-specific
  • Versioned: Consent tied to SDK version
Storage Format: 
{
  "userId": "anon_user_123",
  "consents": {
    "biosignals": {
      "granted": true,
      "timestamp": 1704067200,
      "sdkVersion": "1.0.0"
    },
    "phoneContext": {
      "granted": true,
      "timestamp": 1704067200,
      "sdkVersion": "1.0.0"
    },
    "behavior": {
      "granted": false,
      "timestamp": null,
      "sdkVersion": null
    },
    "cloudUpload": {
      "granted": false,
      "timestamp": null,
      "sdkVersion": null
    }
  }
}
Users can revoke consent at any time: 
await Synheart.revokeConsent('biosignals');
Effects:
  • Module immediately stops collecting data
  • Existing local data is NOT deleted (user controls via separate data deletion API)
  • HSI axes dependent on revoked module return null
  • Cloud uploads stop immediately

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Enforcement Mechanisms

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Module-Level Enforcement

Each module checks consent before processing: 
class WearModule {
  Future<void> collectBiosignals() async {
    // Check consent before collection
    if (!await ConsentModule.hasConsent('biosignals')) {
      return;  // No collection
    }

    // Proceed with collection
    final hrData = await fetchHeartRate();
    processHRData(hrData);
  }
}

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HSI Runtime Enforcement

HSI Runtime respects consent when computing state: 
HSI computeHSI(SignalBundle signals) {
  final hsi = HSI();

  // Only compute axes if consent granted
  if (ConsentModule.hasConsent('biosignals')) {
    hsi.affect.arousalIndex = computeArousal(signals.wear);
  } else {
    hsi.affect.arousalIndex = null;  // Not 0.0, but null
  }

  if (ConsentModule.hasConsent('behavior')) {
    hsi.engagement.engagementStability = computeEngagement(signals.behavior);
  } else {
    hsi.engagement.engagementStability = null;
  }

  return hsi;
}

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Cloud Upload Enforcement

Cloud Connector requires explicit cloudUpload consent: 
await Synheart.enableCloud();  // Requests cloudUpload consent

// Before each upload
if (await ConsentModule.hasConsent('cloudUpload')) {
  await uploadHSISnapshot(hsi);
} else {
  // No upload
}
  1. Contextual Requests: Ask for consent when the feature is first needed
  2. Clear Explanations: Explain what data is collected and why
  3. Granular Options: Allow users to grant/deny each module independently
  4. Easy Revocation: Provide settings UI to revoke consent
┌─────────────────────────────────────┐
│  Enable Biosignal Monitoring?       │
├─────────────────────────────────────┤
│                                     │
│  This allows Synheart to:           │
│  • Read heart rate from your watch  │
│  • Analyze sleep patterns           │
│  • Detect physical activity         │
│                                     │
│  Synheart does NOT access:          │
│  • Raw ECG or PPG data              │
│  • Location or GPS                  │
│  • Direct identifiers (name, email, phone) │
│                                     │
│  [Learn More]  [Deny]  [Allow]      │
└─────────────────────────────────────┘

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Settings UI

Apps should provide a settings screen where users can:
  • View current consent status
  • Revoke any consent
  • Delete local data
  • Export or delete cloud data
Consent and Capabilities are separate but related:
ConceptEnforcesScope
ConsentUser permission to collect dataPer-user, per-device
CapabilityApp permission to access featuresPer-app, server-issued
Example:
  • External app has Core capability → can access basic HSI
  • External app has user consent for biosignals → can compute arousalIndex
  • External app does NOT have user consent for behavior → engagementStability is null
  • Internal app has Extended capability + user consent → can access full 64D embeddings
Enforcement: 
Data Collection = Consent (user) AND Capability (app)

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Data Retention & Deletion

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Local Data

Synheart Core stores minimal local data:
  • HSI snapshots (last 24 hours, rolling window)
  • Consent preferences
  • Module state caches
User Controls: 
// Delete all local data
await Synheart.deleteLocalData();

// Delete data for specific module
await Synheart.deleteModuleData('biosignals');

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Cloud Data

If cloudUpload consent is granted, HSI snapshots are uploaded. User Controls: 
// Stop cloud uploads
await Synheart.revokeConsent('cloudUpload');

// Delete cloud data (requires API call to Synheart Platform)
await Synheart.deleteCloudData();

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Privacy Guarantees

Even with full consent, Synheart Core NEVER collects:
  • ❌ Raw biosignals (ECG, PPG waveforms)
  • ❌ Message content or URLs
  • ❌ Keyboard input (content)
  • ❌ Specific app names (only hashed context)
  • ❌ Audio or microphone data
  • ❌ Location or GPS
  • ❌ Photos or media files
  • ❌ Contact lists or identifiers
With appropriate consent, Synheart Core collects:
  • ✅ Derived biosignals (HR, HRV, sleep stages)
  • ✅ Device motion patterns
  • ✅ Screen on/off state
  • ✅ Interaction timing (taps, scrolls)
  • ✅ Hashed app context (non-reversible)
  • ✅ HSI state representations
When the SDK is updated, consent may need to be re-requested if:
  1. New data types are collected
  2. Privacy policy changes
  3. Module behavior changes
Version Check: 
// Check if consent is valid for current SDK version
bool isValid = await ConsentModule.isConsentValid('biosignals');

if (!isValid) {
  // Re-request consent
  await showConsentDialog('biosignals');
}

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API Reference

// Check consent status
bool hasConsent = await Synheart.hasConsent('biosignals');

// Grant consent
await Synheart.grantConsent('biosignals');

// Revoke consent
await Synheart.revokeConsent('biosignals');

// Get all consent statuses
Map<String, bool> consents = await Synheart.getConsentStatus();

// Delete local data
await Synheart.deleteLocalData();

// Delete cloud data
await Synheart.deleteCloudData();

// Listen for consent changes
Synheart.onConsentChanged.listen((event) {
  print('Consent changed: ${event.consentType} = ${event.granted}');
});

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Unit Tests

test('HSI returns null when consent revoked', () async {
  // Grant consent
  await Synheart.grantConsent('biosignals');

  // Get HSI
  final hsi1 = await Synheart.getLatestHSI();
  expect(hsi1.affect.arousalIndex, isNotNull);

  // Revoke consent
  await Synheart.revokeConsent('biosignals');

  // Get HSI again
  final hsi2 = await Synheart.getLatestHSI();
  expect(hsi2.affect.arousalIndex, isNull);  // Must be null
});
Last Updated: 2025-12-25 Version: 1.0.0 Author: Israel Goytom