How many wearables does WearLink support?

Fourteen providers: Oura, WHOOP, Fitbit, Strava, Withings, Garmin, Polar, Suunto, Ultrahuman, Dexcom, Eight Sleep, Apple Health, Google Health Connect and Samsung Health. Five cloud providers plus three mobile-SDK sources are connectable today; the rest are in provider OAuth onboarding.

Do I need separate code for each wearable?

No. That is the point of the aggregation layer. Every provider normalises into the same schema — a sleep record from an Oura Ring and a sleep record from a Garmin watch are the same object with the same field names and units.

Can I get Apple Health data without an iOS app?

No, and no vendor can offer this. Apple HealthKit is an on-device framework with no cloud API. Reading it requires an iOS app the user has installed and granted permission to. The same is true of Google Health Connect and Samsung Health on Android.

How long does a wearable integration take to build in-house?

Teams typically budget one week per provider and spend three to six months across a handful, because the cost is not the first successful API call — it is OAuth refresh, webhook re-registration, backfill, deduplication across overlapping providers, and keeping up when providers change their schemas.

Wearable API integrations

WearLink connects to fourteen wearable and health-data providers and normalises all of them into one schema. Each guide below covers the provider’s authentication model, how data actually reaches you, which metrics are available, and the specific things that cost teams weeks when they integrate it directly.

The status on each card is reconciled against the runtime configuration flags on the provider status page, so it reflects what is actually wired up rather than what we would like to claim.

Live now

Connectable by an end user today.

Oura Ring API

Live

The Oura Ring API (v2) is one of the cleaner wearable APIs to work with — the documentation is accurate and the daily-summary endpoints are stable. The complexity is not in reading it, it is in keeping it read: Oura backfills and revises data after the fact, so a sleep record you fetched this morning can legitimately change by this evening.

Sleep stages & sleep score · Readiness score · HRV (rMSSD) · Resting heart rate

WHOOP API

Live

WHOOP's developer API exposes the four objects the product is built around — cycles, recovery, sleep and workouts. The data is high quality and the model is coherent, which makes WHOOP a favourite for recovery and readiness products.

Recovery score · Strain · Sleep stages & sleep performance · HRV

Fitbit API

Live

Fitbit has the largest installed base of any dedicated wearable, which makes it the provider most consumer health products need first. It is also the API with the most historical baggage — the surface has accreted since 2011 and it shows in inconsistent date handling and endpoint shapes.

Steps · Sleep stages · Heart rate (intraday where granted) · Calories

Strava API

Live

Strava is the best-instrumented activity API in the consumer space and the only provider in the WearLink catalogue with a true push model — an activity upload triggers a webhook within seconds, not on a poll cycle. If your product cares about workouts rather than sleep or recovery, Strava is usually the fastest path to a working demo.

Activities & workouts · GPS routes · Heart rate streams · Power & cadence

Withings API

Live

Withings is the connected-scale and blood-pressure provider, which makes it the one that matters most for clinical-adjacent products — weight management, hypertension programmes, GLP-1 follow-up and remote patient monitoring. Its data is measurement-shaped rather than continuous: discrete readings taken when a user steps on a scale or straps on a cuff.

Weight & body composition · Blood pressure · Sleep · Heart rate

Mobile SDK sources

On-device only — these require your own iOS or Android app. No vendor can offer them any other way.

Apple HealthKit API

Mobile SDK

Apple Health has no cloud API and never has. Apple does not operate a server you can call — HealthKit is an on-device framework, and the only way to get the data is to run code inside an iOS app the user has installed and granted permission to.

Steps · Heart rate · Workouts · Activity rings

Google Health Connect API

Mobile SDK

Health Connect is Android's on-device health data store and the successor to Google Fit. This matters urgently: the Google Fit APIs have been deprecated, and products still calling them are on a clock.

Steps · Heart rate · Sleep · Workouts

Samsung Health API

Mobile SDK

Samsung Health matters in proportion to Galaxy's market share, which in India and much of Asia is substantial. Galaxy Watch users are a meaningful population that a Fitbit-and-Oura-only integration misses entirely.

Steps · Heart rate · Sleep · Workouts

In provider onboarding

Adapter is written; the OAuth application is awaiting approval from the provider.

Garmin API

Onboarding

Garmin has the broadest data surface of any provider in the catalogue — if a metric exists in consumer wearables, a Garmin device probably measures it. For endurance, military, occupational-health and research use cases it is frequently non-negotiable.

Steps & daily activity · Sleep stages · HRV · Stress & body battery

Polar AccessLink API

Onboarding

Polar's AccessLink API serves a smaller but committed base — endurance athletes, coaching platforms and sports-science teams. Heart rate quality is the reason people choose it; Polar's chest straps remain a reference standard.

Training sessions · Heart rate · Steps · Calories

Suunto API

Onboarding

Suunto is an outdoor and dive-focused brand whose cloud API centres on workout files. For mountaineering, trail and diving products it covers device categories nobody else in this list reaches.

Workouts · Heart rate · HRV · Steps

Ultrahuman Ring API

Onboarding

Ultrahuman is the India-headquartered smart-ring maker and the provider most relevant to South Asian consumer health products, where its installed base is meaningful in a way it is not elsewhere.

Sleep · HRV · Resting heart rate · Steps

Dexcom CGM API

Onboarding

Dexcom is continuous glucose monitoring, and it is the provider whose data is most directly clinical. Interest has grown sharply beyond diabetes care — metabolic health, GLP-1 programmes and performance nutrition products all want CGM traces.

Continuous blood glucose · Glucose trend & rate of change · Calibration events · Device events

Eight Sleep API

Onboarding

Eight Sleep measures sleep from the mattress rather than the wrist, which produces a genuinely different signal: no compliance problem, no charging gap, and thermal data no wearable can supply.

Sleep stages · Bed & ambient temperature · HRV · Respiratory rate

Common questions

How many wearables does WearLink support?: Fourteen providers: Oura, WHOOP, Fitbit, Strava, Withings, Garmin, Polar, Suunto, Ultrahuman, Dexcom, Eight Sleep, Apple Health, Google Health Connect and Samsung Health. Five cloud providers plus three mobile-SDK sources are connectable today; the rest are in provider OAuth onboarding.
Do I need separate code for each wearable?: No. That is the point of the aggregation layer. Every provider normalises into the same schema — a sleep record from an Oura Ring and a sleep record from a Garmin watch are the same object with the same field names and units.
Can I get Apple Health data without an iOS app?: No, and no vendor can offer this. Apple HealthKit is an on-device framework with no cloud API. Reading it requires an iOS app the user has installed and granted permission to. The same is true of Google Health Connect and Samsung Health on Android.
How long does a wearable integration take to build in-house?: Teams typically budget one week per provider and spend three to six months across a handful, because the cost is not the first successful API call — it is OAuth refresh, webhook re-registration, backfill, deduplication across overlapping providers, and keeping up when providers change their schemas.