WearSync 🩺

Open Source Wearable Data Aggregator — bring all your smartwatch data into one place.

Apple Watch · Garmin · Whoop · Fitbit · Withings · Amazfit — unified, local, free.

Why WearSync?

Commercial solutions like Terra API cost $400+/month. WearSync connects directly to each manufacturer's free developer API, normalizes all data into a single schema, and runs entirely on your machine. No cloud. No subscription. No middleman.

Features

• 📊 Live Dashboard — Heart Rate, HRV, Sleep, Activity, Recovery Score
• 📈 Historical Charts — Compare trends across weeks/months
• ⚖️ Device Comparison — Garmin vs Whoop side-by-side, same metric
• 📤 Export — Full data export as CSV or JSON
• 🔒 100% Local — SQLite database, your data stays on your machine
• 🐳 One-command setup via Docker Compose

Supported Devices (v1.0)

Device	API	Status
Garmin	Garmin Health API	✅
Fitbit	Fitbit Web API	✅
Whoop	Whoop API v1	✅
Withings	Withings Health API	✅
Amazfit/Zepp	Zepp Health API	✅
Apple Health	Local JSON export import	✅

Quick Start

Option A: Docker (recommended)

git clone https://github.com/yourusername/wearsync
cd wearsync
cp .env.example .env
# Fill in your API keys in .env
docker compose up

Open http://localhost:3000

Option B: Manual

# Backend
cd backend
npm install
npm run dev

# Frontend (new terminal)
cd frontend
npm install
npm run dev

Getting API Keys (all free)

Garmin

1. Go to https://developer.garmin.com/health-api/
2. Create a developer account
3. Register your app → get GARMIN_CLIENT_ID + GARMIN_CLIENT_SECRET

Fitbit

1. Go to https://dev.fitbit.com/apps/new
2. Register app (Personal use) → get FITBIT_CLIENT_ID + FITBIT_CLIENT_SECRET

Whoop

1. Go to https://developer.whoop.com/
2. Apply for API access (free, usually approved within a day)
3. Create app → get WHOOP_CLIENT_ID + WHOOP_CLIENT_SECRET

Withings

1. Go to https://developer.withings.com/
2. Create account → register app → get keys

Architecture

wearsync/
├── backend/          # Node.js + Express API server
│   └── src/
│       ├── routes/   # API endpoints
│       ├── services/ # Per-device OAuth + data fetching
│       ├── models/   # Normalized data schema
│       └── utils/    # Data normalization helpers
├── frontend/         # React + Vite dashboard
│   └── src/
│       ├── components/
│       ├── pages/
│       └── hooks/
└── docker-compose.yml

Normalized Data Schema

All device data is normalized before storage:

{
  "device": "garmin",
  "user_id": "local",
  "timestamp": "2026-03-23T08:00:00Z",
  "metrics": {
    "heart_rate": { "avg": 62, "min": 48, "max": 120, "unit": "bpm" },
    "hrv": { "value": 58, "unit": "ms" },
    "sleep": { "duration": 27480, "score": 82, "unit": "seconds" },
    "activity": { "steps": 9400, "calories": 2340, "active_minutes": 48 },
    "recovery": { "score": 76, "unit": "percent" }
  }
}

Contributing

PRs welcome! See CONTRIBUTING.md.

License

MIT — free forever.