Add Health Data to Apple Health via API

Send readings from your scale, smart home or own software to Syncvita over HTTP. The iOS app adds them to Apple Health automatically.

iOS App
  • Free, no sign-up
  • Servers in Germany
  • 7 data types
  • No analysis, no sharing
POST https://api.syncvita.de/v1/weight
Authorization: Bearer YOUR_API_KEY

{"weight": 72.5, "unit": "kg"}
Apple Health just now

Weight

72.5 kg

Added by Syncvita

Four steps to Apple Health

It takes about five minutes from signing up to seeing your first value in Apple Health. You only need to write code if you want to send data automatically.

  1. Generate an API key

    Click “Generate API key”. You get a free key instantly – no registration, no email address required.

  2. Install the iOS app

    Download the Syncvita app from the App Store, enter your key and grant it write access to Apple Health.

  3. Send data via the API

    POST your measurement as JSON to the matching endpoint, for example https://api.syncvita.de/v1/steps with the header Authorization: Bearer YOUR_API_KEY.

  4. The value lands in Apple Health

    The app receives a push notification, fetches the value, writes it into Apple Health through HealthKit and reports it back as synced.

From app version 1.8

Analyse your health data with AI

If you want, it also works the other way round: the app transfers selected Apple Health data to Syncvita. You can then ask Claude, ChatGPT or any other AI application that supports MCP how your sleep, heart rate or weight are developing – including local AIs.

  • Optional and off by default

    Nothing is transferred until you explicitly switch on the export in the app and give your consent.

  • You decide what and how much

    An assistant asks which data types and how much history to transfer: 30 days, 90 days, one year or everything.

  • Stored in Germany

    The data is transferred encrypted and stored on our server in Germany. No advertising, no sale, no sharing – except with an AI assistant you connect yourself.

  • Stop and delete at any time

    One tap in the app ends the export and immediately deletes all transferred data from our server.

Guide: connect AI assistants Details on purpose, retention and your rights

For developers: one request is enough

Every endpoint works the same way: send JSON, pass a bearer token in the header, done. No SDK, no OAuth dance, no app development.

curl -X POST https://api.syncvita.de/v1/steps \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"steps": 5234, "date": "2026-08-24"}'
await fetch('https://api.syncvita.de/v1/heart-rate', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ bpm: 72, date: '2026-08-24', time: '14:30:00' })
});
import requests

requests.post(
    "https://api.syncvita.de/v1/weight",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={"weight": 75.5, "unit": "kg", "date": "2026-08-24"},
)
Endpoints and value ranges at a glance
Data type Endpoint Required field Valid range
Steps POST /v1/steps steps 0 – 100.000
Weight POST /v1/weight weight 0 – 500 (kg / lbs)
Heart Rate POST /v1/heart-rate bpm 20 – 300
Blood Oxygen POST /v1/blood-oxygen spo2 0 – 100 %
Body Fat POST /v1/body-fat percentage 0 – 100 %
Blood Sugar POST /v1/blood-sugar glucose 10 – 600 mg/dL
Hydration POST /v1/hydration milliliters 0 – 10.000 ml

Every endpoint additionally accepts the optional fields date and time (steps use start_time and end_time). POST /v1/bulk sends several measurements in a single request. The rate limit is 100 requests per hour per API key.

API documentation No code: enter values in the browser

Frequently asked questions about the Apple Health API

The questions we get asked most often, answered briefly and concretely.

No. Apple Health offers no official web API. HealthKit is only accessible to apps running on the user’s own device, and all health data stays stored locally on the iPhone. There is no way to write into Apple Health directly from a server. Syncvita works exactly within that boundary: the API receives your data, and the Syncvita iOS app on your iPhone writes it into Apple Health through HealthKit.

Generate a free API key on syncvita.de, install the Syncvita iOS app and enter the key there. Then send your measurement as a JSON POST to the matching endpoint, for example POST https://api.syncvita.de/v1/steps with the body {"steps": 5234, "date": "2026-08-24"}. The app fetches the value and writes it into Apple Health.

Seven data types: steps (0–100,000), weight (0–500 kg or lbs), heart rate (20–300 bpm), blood oxygen / SpO2 (0–100%), body fat percentage (0–100%), blood sugar (10–600 mg/dL) and hydration (0–10,000 ml). Each type has its own endpoint under https://api.syncvita.de/v1/.

No. The web form at syncvita.de/manage-data.php lets you enter values directly in the browser. You only need to write code if you want to automate the transfer – and then a single HTTP request is enough, which any scripting language, Home Assistant, n8n, Make or Apple Shortcuts can send.

Yes. Generating API keys, using the API and the iOS app are all free. A rate limit of 100 requests per hour per key applies, which is comfortably enough for personal automation.

Every transfer runs exclusively over HTTPS and is authenticated with a bearer token. Data is stored on our server in Germany and is not deleted automatically. You can delete all data or only data before a certain date at any time – in the app, in the web app under "Manage data" or via the API. We only store the optional Apple Health export if you explicitly turn it on. We do not analyse your data, sell it or pass it on – except to an AI application you connect yourself. There are no user accounts, and we collect no names and no email addresses. Details are in the privacy policy.

Yes, from version 1.7 of the iOS app – but only if you explicitly switch it on. An assistant asks which data types (for example weight, heart rate, sleep or workouts) and how much history to transfer. Without your consent, nothing leaves your iPhone.

The export stops immediately and all transferred Apple Health data is deleted from our server. If you only deselect individual data types, we delete exactly that data. Your regular sync into Apple Health continues independently.

Yes, from app version 1.8. If you have turned on the Apple Health export in the app, you can connect Claude, ChatGPT or any other AI application that supports MCP – including a local AI – to the data you shared and ask it questions about it. The connection requires its own, separate consent in the app, only allows reading and can be disconnected there at any time. The step-by-step guide is at syncvita.de/connect-ai.php.

Yes. Create a RESTful command automation in Home Assistant that POSTs to the matching Syncvita endpoint and passes your API key in the Authorization header. That way readings from Zigbee scales, blood pressure monitors or your own sensors end up in Apple Health.

Yes. Syncvita writes directly into Apple Health on the iPhone. No Apple Watch is required – people without a Watch in particular use Syncvita to consolidate data from third-party wearables and measuring devices in Apple Health.

Because Apple technically restricts write access to HealthKit to apps running on the device. Without an app on the iPhone, no service in the world can write data into Apple Health. The Syncvita app takes care of exactly that part so you do not have to build your own iOS app.

Not at the moment. Syncvita is built around Apple Health and HealthKit. The API itself is platform independent – you can send from any system that speaks HTTP, be it a Linux server, a Windows PC or an Android device. Only the destination is an iPhone.

The iOS app connects it all

The app picks up new values via push notification and adds them to Apple Health. It runs on iPhone and iPad; an Apple Watch is not required.

Download on the App Store
Syncvita iOS App Screenshot – Add Health Data to Apple Health via API