Data Sync & Background Jobs

Wearable data synchronization is managed through Junction Health (Vital API) integration, deployed as a Render.com cron job.

Junction Health Integration

Loop uses Junction Health (powered by Vital API) as a unified wearable data aggregator. This provides:

• Single API for 50+ wearable devices (Oura, Whoop, Apple Health, Fitbit, etc.)
• Automatic OAuth token management
• Standardized data format across all devices
• Historical data backfill support

Sync Jobs

wearable-sync-daily (Render.com Cron)

Schedule: Daily at 3:00 AM UTC Platform: Render.com (auto-deployed from render.yaml) Source: apps/background-jobs/wearable-sync

Syncs wearable data from Junction/Vital API to patient-graph database.

Process:

1. Read user IDs from JUNCTION_SYNC_USER_IDS environment variable
2. For each user:
   • Fetch last 7 days of wearable data from Junction API (configurable via JUNCTION_SYNC_LOOKBACK_DAYS)
   • Includes: sleep, activity, heart rate, recovery metrics
   • Store raw readings in patient_graph.patient_wearable_readings
   • Upsert daily aggregates in patient_graph.patient_wearable_daily_stats
3. Retry failed syncs up to 3 times with exponential backoff
4. Log comprehensive sync summary (users synced, records stored, errors)

Configuration:

// apps/background-jobs/wearable-sync/index.ts
export async function runWearableSyncJob(config: {
  junctionApiKey: string;
  patientGraphApiUrl: string;
  patientGraphApiKey: string;
  userIds: string[];
  lookbackDays?: number; // Default: 7
  environment?: "production" | "sandbox";
  region?: "us" | "eu";
}): Promise<Result<{ results: UserSyncSummary[] }>>

Environment Variables:

• JUNCTION_API_KEY - Vital API key
• PATIENT_GRAPH_API_URL - Patient Graph API endpoint
• PATIENT_GRAPH_API_KEY - API authentication key
• JUNCTION_SYNC_USER_IDS - Comma-separated Vital user IDs (e.g., user_123,user_456)
• JUNCTION_SYNC_LOOKBACK_DAYS - Days to sync (default: 7)
• JUNCTION_ENV - production or sandbox
• JUNCTION_REGION - us or eu

Deployment:

# Automatically deployed on push to main via render.yaml
git push origin main
 
# Check deployment status
# Visit: https://dashboard.render.com → wearable-sync-daily

syncWhoopData

Schedule: Daily

Dedicated Whoop data sync job for recovery, strain, sleep, and workout data.

syncCgmReadings

Schedule: Every 30 minutes

Syncs CGM readings from Dexcom and Libre devices.

Process:

1. Query all active CGM connections
2. For each connection:
   • Refresh OAuth tokens if needed
   • Fetch glucose readings since lastSyncAt
   • Store in patient_glucose_readings
   • Update lastSyncAt on the connection record

aggregateWearableData

Schedule: Daily after sync jobs

Computes daily statistics from raw wearable readings:

• Average, min, max for each metric type
• Rolling 7-day and 30-day averages
• Stores in patient_wearable_daily_stats

cleanupWearableData

Schedule: Weekly

Removes expired or redundant wearable data:

• Raw readings older than 90 days (daily stats are retained)
• Orphaned records from disconnected devices
• Duplicate readings

Manual Sync

Users can trigger a manual sync from the consumer app:

curl -X POST "https://my.loop.health/api/patient-graph/wearables/sync" \
  -H "Authorization: Bearer $CLERK_JWT" \
  -H "Content-Type: application/json" \
  -d '{ "source": "oura" }'

Or for the generic wearable endpoint:

curl -X POST "https://my.loop.health/api/wearables/oura/sync" \
  -H "Authorization: Bearer $CLERK_JWT"

Error Handling

Monitoring

Sync job health is monitored via:

• Trigger.dev dashboard — Job status, duration, failure rates
• Sentry — Error tracking and alerting
• Patient events — wearable_sync events for audit trail