Privacy Policy

Last updated: 2026-10-07

health4.ai ("we", "us") provides an iOS app and MCP server that facilitate the transfer of Apple HealthKit data to a destination you configure and control: a spreadsheet in your own Google Drive or a Postgres/Supabase database. We do not operate a shared health-data backend or collect, store, or have access to your health data. This policy explains what limited data we do collect and your rights.

1. What data we collect

Health data: we do not collect it. HealthKit metrics you authorize flow directly from your device to a spreadsheet in your own Google Drive (if you choose Save to Google Sheets; see section 4) or to a Supabase project you create and own. health4.ai never receives, stores, or has access to your health data. A cloud AI provider you separately connect to may process data you choose to send to it.
Account data: before launch, we collected email addresses from pre-launch waitlist sign-ups to notify people when the app shipped and, for those who opted in, to send a TestFlight beta invitation. The app is now live on the App Store and we no longer collect waitlist emails.
Usage data: anonymous page views and feature interaction events via PostHog (US-hosted). PostHog never receives health data. We do not use advertising cookies or trackers.

2. How we use it

Previously, to notify pre-launch waitlist sign-ups when the app shipped on the App Store. That notification has gone out and this collection is closed.
TestFlight invitations (historical): opt-in, and shared with Apple. During the pre-launch beta, if you ticked the TestFlight box when joining the waitlist, we passed your email address to Apple's App Store Connect so Apple could send you a beta invitation. Apple sent that email, not us. Anyone with administrator access to our App Store Connect account could see the addresses of enrolled testers. If you were a tester, ask us at any time to remove you.
To improve reliability: aggregated, non-identifiable usage metrics only.

We do not sell personal data. We do not use health data for advertising. Per Apple's HealthKit guidelines, health data will never be used for advertising or sold to data brokers. Because we never receive your health data, we are structurally incapable of misusing it.

3. Where data is stored

Your health data lives in the destination you choose: a spreadsheet in your own Google Drive (see section 4), or a Supabase project you create and own. You hold the credentials, and only you can access the data. health4.ai has no access to it.

4. Google Sheets destination

health4.ai offers a destination, "Save to Google Sheets", that writes your health summaries into a spreadsheet in your own Google Drive instead of a database. It is available in version 1.0.1 of the app and later. If you never connect a Google account, none of this section applies and we receive nothing from Google.

What Google data the app accesses. When you choose this destination, the app asks you to sign in to Google on your device and requests a single permission (OAuth scope): https://www.googleapis.com/auth/drive.file. This scope limits the app to files it creates itself. health4.ai cannot see, list, or open any other file in your Google Drive, and it does not request your name, email address, contacts, calendar, or Gmail.
How it is used. The app creates one spreadsheet in your Drive and writes daily health summaries and workout rows into it, directly from your iPhone to Google's Sheets API. That is the only purpose.
How it is stored. The Google sign-in token (a refresh token) is stored in the iOS Keychain on your device. It never leaves your phone except to talk to Google. The health rows live in your Google Drive, under your Google account and Google's own security.
How it is shared. It is not shared. No Google user data or health data is sent to health4.ai or to any server we operate. We do not sell it, use it for advertising, or transfer it to anyone else, and no human at health4.ai reads it, because we never receive it. The app talks to Google directly and to no one else on this path.
Revoke access. In the app, disconnect Google Sheets; the app revokes its token with Google and forgets it. You can also remove access at any time in your Google Account under Security → Third-party connections, or at myaccount.google.com/permissions. Either way, sync stops.
Delete. Disconnecting does not delete the spreadsheet; it is your file, and you can delete it in Google Drive whenever you like. Erasing the app's data removes the stored sign-in token from your device's Keychain. Because we hold none of this data, there is nothing on our side to delete.

Google API Services User Data Policy. health4ai's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

5. HIPAA

health4.ai is not a covered entity under HIPAA and does not operate as a HIPAA Business Associate unless a Business Associate Agreement (BAA) is separately executed in writing.

6. Your rights

Health data control: your health data is in your Google Sheet or your database. You can delete it directly at any time, with no request to us required.
Account deletion: contact us to delete any account data we hold on you. We will confirm deletion within 14 days.
Revoke HealthKit access: stop syncing at any time in iPhone Settings → Privacy & Security → Health → health4.ai. No data is deleted from your Google Sheet or database automatically; you remain in full control.
GDPR / CCPA: EU and California residents have additional rights (portability, rectification, opt-out of sale). We do not sell personal data. Contact us to exercise any right over account data we hold.

7. Breach notification

Because health4.ai does not store your health data, a breach of our systems cannot expose it. In the unlikely event of a breach involving account data (email addresses), we will notify affected users within 30 days.

8. Analytics & cookies

We use PostHog (US-hosted) for product analytics. PostHog receives page views and feature interaction events, and no health data. We do not use advertising cookies or trackers.

9. Changes to this policy

We will update the "Last updated" date and notify users by email of any material changes.

10. Contact

Questions or data requests: privacy@health4.ai