Stream FITINDEX data. No FITINDEX API needed.
FITINDEX smart scales write weight, body fat, BMI, height, and their BMR estimate — which arrives as basal energy burned — to Apple Health, and Sahha’s SDK reads them into your app as normalized body biomarkers, alongside every other source.
- On-device
- Apple Health
- iOS
- HIPAA
- GDPR
Free for 30 days · No credit card
- Weight
- 74.1 kg
- Body fat
- 19.4 %
- BMI
- 23.8 —
- Basal energy
- 1,610 kcal
Identical schema across 500+ sources
Your users connect FITINDEX. Sahha does the rest.
This is your user’s side of the story — one screen, once. Sahha ingests every FITINDEX signal, normalizes, deduplicates, and delivers it to your service — raw, or as refined intelligence your product can act on.
A Allow "your app"
On-device and permissioned
FITINDEX data is read on the user’s own device, only after they grant Apple Health permission — nothing syncs without consent.
One integration, every source
Permission is per data type, not per brand. Anything that writes to Apple Health — FITINDEX today, a new watch next year — flows through the same SDK with no extra prompt and no new code.
What FITINDEX syncs through Apple Health.
Request only what you need
You choose exactly which of these signals to request from Apple Health — users are only ever prompted for those, which keeps opt-in rates high.
One schema, every source
FITINDEX, Apple Watch, and Oura all return the same fields and units.
What crosses the bridge
Weight, body fat, BMI, height, and BMR as basal energy burned pass through Apple Health; some app-exclusive metrics may not.
Body
5
HealthKitSahha- bodyMassweightkg
- bodyFatPercentagebody_fat%
- bodyMassIndexbody_mass_index
- heightheightcm
- basalEnergyBurnedbasal_energy_burnedkcal
See a real payload
{
"type": "HKQuantityTypeIdentifierBodyMass",
"value": 74.1,
"unit": "kg",
"startDate": "2026-06-02T07:02:00Z",
"sourceRevision": { "source": { "name": "FITINDEX" } }
// …body fat, BMI, height & basal energy samples
}[
{
"category": "body",
"type": "weight",
"value": 74.1,
"unit": "kg",
"periodicity": "spot",
"aggregation": "last",
"startDateTime": "2026-06-02T07:02:00Z",
"endDateTime": "2026-06-02T07:02:00Z"
},
{
"category": "body",
"type": "body_fat",
"value": 19.4,
"unit": "percent",
"periodicity": "spot",
"aggregation": "last",
"startDateTime": "2026-06-02T07:02:00Z",
"endDateTime": "2026-06-02T07:02:00Z"
}
// …3 more normalized logs
]FITINDEX writes weight, body fat, BMI, height, and its BMR estimate to Apple Health each time the user steps on the scale — the BMR figure lands as basal energy burned, Apple Health’s resting-energy field. The scale still measures a fuller bioimpedance breakdown than Apple Health can represent: there’s no fat-mass field, so that reading stays in the FITINDEX app, along with muscle, visceral fat and metabolic age. Bear in mind that bioimpedance body composition is an estimate: it moves with hydration and time of day, so it’s most useful as a trend rather than an absolute number. Health Connect is essentially absent from the smart-scale category, and FITINDEX’s Android path is Google Fit or nothing — so this is an iOS-only integration.
Missing a metric you need? Talk to us in the Sahha Slack — if FITINDEX captures it, we can usually add support.
Get more than just raw data
Sahha turns these signals into biomarkers, scores, archetypes, and insights — the modeling done for you.
Reading Apple Health yourself? Here’s the to-do list.
Everything on the left is yours to write, test, and maintain on iOS. Everything on the right, Sahha already did.
- Integrate Apple Health.
- Handle iOS version differences.
- Add Health Connect separately for Android.
One SDK covers Apple Health, Health Connect, and every cloud source.
- Write the HealthKit queries.
- Request the right permissions.
- Wire up background delivery.
The SDK handles queries, permissions, and background sync.
- Dedupe apps writing the same metric.
- Map dozens of HealthKit types.
- Reconcile against your Android sources.
Deduped, typed, one schema — one stream per user.
- Build a sleep model.
- Build an activity model.
- Hire a data scientist.
Scores, archetypes, and insights — built in.
- Apple changes a HealthKit API.
- You find out in production.
We version the SDK. You never notice.
No FITINDEX developer account needed — Sahha reads what FITINDEX already writes to Apple Health on iOS.
Live in an afternoon, not a sprint.
- # Add the Sahha SDKnpm install sahha-react-native01
Add the Sahha SDK
Drop the Sahha SDK into your iOS app — or React Native or Flutter. The same SDK also covers Health Connect for your Android sources.
- A
Allow “your app”
ConnectSleepActivityHeart rate02Prompt for Apple Health permissions
Call the SDK to show the native Apple Health consent sheet. The user chooses what to share — under your brand. It’s one prompt, ever: permission is per data type, not per brand, so every future source is already covered.
- Your app LIVESleep7h 12mReadiness82Heart rate62 bpm03
Sahha reads and delivers
Once permission is granted, the SDK reads FITINDEX data from Apple Health in the background, normalizes it to one schema, and streams it to your app by webhook or API.
Most teams read live FITINDEX data the same day they add the SDK. The only per-source prerequisite: your user has FITINDEX’s Apple Health sync switched on — most source apps enable it by default.
Route it into your stack.
Sahha streams every update to your webhook — and a step-by-step guide takes it the rest of the way into your database, CDP, or messaging tool.
FITINDEX integration questions
How does Sahha get FITINDEX data?
FITINDEX scales write to Apple Health through the FITINDEX app, and Sahha reads them from there with its mobile SDK — so you get body-composition data without integrating the FITINDEX API directly.
Which FITINDEX metrics does Sahha provide?
Weight, body fat percentage, BMI, height, and the scale’s BMR estimate, which arrives as basal energy burned — Apple Health’s resting-energy field. All of it is normalized to Sahha’s schema, and these are spot readings taken each time the user weighs in.
What FITINDEX data doesn’t cross?
The scale measures a fuller bioimpedance breakdown than Apple Health can represent. Apple Health has no fat-mass field, so that reading stays in the FITINDEX app — as do muscle mass, visceral fat and metabolic age. Body fat percentage, weight, and the BMR estimate do cross, the last as basal energy burned. It’s also worth treating the composition figures that do cross as estimates: bioimpedance readings shift with hydration and time of day, so they’re most useful as a trend rather than an absolute.
Does the FITINDEX integration work on Android?
No. Health Connect is essentially absent from the smart-scale category, and FITINDEX’s Android path is Google Fit or nothing — so this is an iOS-only integration. Your users’ other Android sources still flow through the same Sahha SDK.
Is the FITINDEX integration HIPAA and GDPR compliant?
Yes. Sahha is HIPAA and GDPR compliant and SOC 2 certified, and FITINDEX data flows through the same compliant pipeline as every other source.
One API for every other source, too.
Add another wearable or app and the schema, webhooks, and scores are identical — no new pipeline to build.
Start streaming FITINDEX data today.
Connect once. Sahha handles consent, normalization, and real-time delivery — for FITINDEX and every other source.
Free for 30 days · No credit card
- One API for FITINDEX and every other source
- Real-time webhooks + on-demand REST, one normalized schema
- Scores, archetypes & insights — no modeling required
- HIPAA, GDPR & SOC 2 · your brand on the consent screen