Feelfit Integration

Stream Feelfit data. No Feelfit API needed.

Feelfit is the companion app for the Qingniu, Yolanda, and QN-Scale family of smart scales. It writes weight, body fat, BMI, and lean mass to Apple Health — and Sahha’s SDK reads them into your app as normalized body-composition biomarkers, alongside every other source.

On-device
Apple Health
iOS
HIPAA
GDPR

Start building Read the SDK docs

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Normalized Auto-synced

Weight: 74.1 kg
Body fat: 19.4 %
Lean mass: 59.7 kg

Identical schema across 500+ sources

How it works

Your users connect Feelfit. Sahha does the rest.

This is your user’s side of the story — one screen, once. Sahha ingests every Feelfit signal, normalizes, deduplicates, and delivers it to your service — raw, or as refined intelligence your product can act on.

Allow "your app"

Sleep

Activity

Heart rate

Connect

9:41LIVE

82READY

Sleep7h 12m

Steps5,993

Heart rate62 bpm

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Sahha

Permissions handled

Encrypted in transit

History backfilled

Background sync enabled

Cleaning · deduping · scoring

Raw data logs Biomarkers Scores Insights Archetypes Tags

Real-time webhooks

Always in sync

Query via API

Access controlled

Your service

Waiting for data…

On-device and permissioned

Feelfit 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 — Feelfit today, a new watch next year — flows through the same SDK with no extra prompt and no new code.

Data coverage

What Feelfit 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
Feelfit, Apple Watch, and Oura all return the same fields and units.
What crosses the bridge
Weight, body fat, BMI, and lean mass pass through Apple Health; some app-exclusive metrics may not.

Body

HealthKitSahha

bodyMassweightkg
bodyFatPercentagebody_fat%
bodyMassIndexbody_mass_index
leanBodyMasslean_masskg

See a real payload

HealthKit · body

{
  "type": "HKQuantityTypeIdentifierBodyMass",
  "value": 74.1,
  "unit": "kg",
  "startDate": "2026-06-02T07:02:00Z",
  "sourceRevision": { "source": { "name": "Feelfit" } }
  // …body fat, BMI & lean mass samples
}

Sahha · normalized

[
  {
    "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"
  }
  // …2 more normalized logs
]

Feelfit writes weight, body fat, BMI, and lean mass to Apple Health each time the user steps on the scale. It’s a platform app spanning several brands — Qingniu, Yolanda, and the QN-Scale line — so readings arrive attributed to Feelfit rather than to the individual scale brand. Bioimpedance body composition is an estimate that varies with hydration and time of day, so treat it as a trend rather than an absolute. Health Connect is essentially absent from the smart-scale category, and Feelfit’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 Feelfit 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.

Biomarkers

Scores

Archetypes

Insights

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.

Build it yourself

With Sahha

Every device

Build it yourself

Integrate Apple Health.
Handle iOS version differences.
Add Health Connect separately for Android.

With Sahha

One SDK covers Apple Health, Health Connect, and every cloud source.

Getting the data

Build it yourself

Write the HealthKit queries.
Request the right permissions.
Wire up background delivery.

With Sahha

The SDK handles queries, permissions, and background sync.

Keeping it clean

Build it yourself

Dedupe apps writing the same metric.
Map dozens of HealthKit types.
Reconcile against your Android sources.

With Sahha

Deduped, typed, one schema — one stream per user.

Turning it into insight

Build it yourself

Build a sleep model.
Build an activity model.
Hire a data scientist.

With Sahha

Scores, archetypes, and insights — built in.

Keeping it alive

Build it yourself

Apple changes a HealthKit API.
You find out in production.

With Sahha

We version the SDK. You never notice.

No Feelfit developer account needed — Sahha reads what Feelfit already writes to Apple Health on iOS.

Setup

Live in an afternoon, not a sprint.

# Add the Sahha SDKnpm install sahha-react-native
01
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”
Sleep
Activity
Heart rate
Connect
02
Prompt 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 LIVE
Sleep7h 12m
Readiness82
Heart rate62 bpm
03
Sahha reads and delivers
Once permission is granted, the SDK reads Feelfit data from Apple Health in the background, normalizes it to one schema, and streams it to your app by webhook or API.

Start building Read the SDK docs

Most teams read live Feelfit data the same day they add the SDK. The only per-source prerequisite: your user has Feelfit’s Apple Health sync switched on — most source apps enable it by default.

Destinations

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.

FAQ

Feelfit integration questions

How does Sahha get Feelfit data?

Feelfit scales write to Apple Health through the Feelfit app, and Sahha reads them from there with its mobile SDK — so you get body-composition data without integrating the Feelfit API directly.

Which Feelfit metrics does Sahha provide?

Weight, body fat percentage, BMI, and lean body mass — normalized to Sahha’s schema. These are spot readings taken each time the user weighs in, and the composition figures are bioimpedance estimates that shift with hydration and time of day, so they read best as a trend.

Which scales does the Feelfit app cover?

Feelfit is the companion app for the Qingniu, Yolanda, and QN-Scale family, so one app spans several brands. Readings arrive in Apple Health attributed to Feelfit rather than to the individual scale brand — worth knowing if you’re labelling sources in your own UI.

Does the Feelfit integration work on Android?

No. Health Connect is essentially absent from the smart-scale category, and Feelfit’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 Feelfit integration HIPAA and GDPR compliant?

Yes. Sahha is HIPAA and GDPR compliant and SOC 2 certified, and Feelfit data flows through the same compliant pipeline as every other source.