HealthFold Privacy Policy

Effective date: October 15, 2026

HealthFold is developed by Lengjie (Beijing) Technology Co., Ltd. (“we”, “us”). HealthFold has two parts: the HealthFold app for iPhone (the “iPhone app”) and the free HealthFold app for Mac that you download from our website and install on your own Mac (the “Mac app”). This policy explains what data the two parts handle, where that data is kept, and how you control it.

In short: your health data goes only from your iPhone to the Mac you paired, and stays on that Mac. We have no server that receives it, and we cannot see it.

1. We don’t collect your data

• HealthFold has no accounts. There is nothing to sign up for or sign in to.
• We do not run any server that receives or stores health data. Your health data is never sent to us.
• Neither app includes analytics, advertising, crash-reporting or any other third-party SDK.
• We do not track you, sell your data, use it for advertising, or share it with data brokers.
• HealthFold does not upload health data to iCloud. This does not affect the Health app’s own iCloud sync, which is controlled by your Apple settings.

Accordingly, HealthFold’s App Privacy label on the App Store is “Data Not Collected”.

2. What the iPhone app reads

With your permission on the system Health access screen, the iPhone app reads the following categories from the Health app, read-only. You can turn on only some of them; categories you don’t allow are never read.

• Activity: steps, walking + running distance, cycling and swimming distance, flights climbed, active and resting energy, exercise minutes, stand minutes and stand hours, Activity ring summaries, and similar.
• Heart: heart rate, resting heart rate, walking heart rate average, heart rate variability, heart rate recovery, cardio fitness (VO2 max), and ECG recordings with their classification.
• Respiratory: blood oxygen, respiratory rate.
• Sleep and mindfulness: sleep analysis (in bed, sleep stages, awake) and mindful minutes.
• Body measurements: weight, height, body mass index, body fat percentage, lean body mass.
• Mobility and running metrics: walking speed, step length, double support time, walking asymmetry, walking steadiness, running speed, stride length, ground contact time, vertical oscillation, running power, stair speed up and down, six-minute walk distance, physical effort, and similar.
• Workouts: workout type, time, duration, distance, energy and so on, plus GPS routes if you allow Workout Routes.
• Environment and other: environmental sound and headphone audio levels, environmental sound reduction, time in daylight, handwashing events.

The iPhone app never writes anything to the Health app, and never changes or deletes data in it.

The iPhone app keeps only a small amount of information on the iPhone itself: pairing details (your Mac’s local network address and pairing credentials), sync progress, and a local log used only for troubleshooting. This information is not sent anywhere else.

3. Where the data goes: only to your own Mac

• The iPhone app sends data only to the Mac you paired, and both devices must be on the same Wi-Fi or local network. The data does not travel over the internet and does not pass through our servers or anyone else’s.
• After pairing, the last 90 days are synced first; older history is filled in in the background, and new data keeps syncing.
• The Mac app stores the data in a local SQLite database on that Mac, under ~/Library/Application Support/HealthFold. These files are protected by your macOS user account, and we recommend turning on FileVault. Anyone who can sign in to that account on that Mac can see the data.
• You can also import a zip file exported from the Health app into the Mac app. Imported data likewise stays on that Mac only.
• In the current free version, each Mac holds data for one person.

4. How data is protected in transit

Data synced between your iPhone and your Mac is end-to-end encrypted:

• When you scan the pairing QR code shown on your Mac, the code contains that Mac’s public key. The iPhone and the Mac use X25519 key agreement to derive keys known only to the two devices, and health data is then sent encrypted with ChaCha20-Poly1305, so other devices on the network cannot read or alter it.
• If you pair without scanning (for example by typing the 6-digit code, or connecting manually in advanced settings), the iPhone trusts the Mac it reaches the first time and keeps trusting that Mac afterwards. This means that if someone on the same network were impersonating your Mac at the moment of manual pairing, the iPhone could not tell. Please do manual pairing on a network you trust (such as your home Wi-Fi), and prefer scanning the QR code when you can.
• Once the data reaches your Mac, it is decrypted and stored in the local database described in Section 3.
• Sync acknowledgements are authenticated and bound to the exact request. An unverified response cannot advance sync progress. If a valid device key is missing, the iPhone requires pairing again instead of sending health data unencrypted.

5. Pairing and the camera

• You pair by scanning the QR code shown on your Mac with your iPhone. The pairing parameters are placed after the # in the link (the URL fragment), which browsers never send to the web server. So even if the app isn’t installed yet and the code opens our pairing page in Safari, our website never receives the pairing parameters.
• The camera is used only to scan the pairing QR code. The image is processed live on the device and is never saved or sent anywhere. If you prefer not to use the camera, you can type the 6-digit pairing code instead.
• The Local Network permission is used to find and connect to your Mac on your local network.

6. Letting AI tools read your data (optional, set up by you on the Mac)

• In the Mac app’s “Connect AI” tab you can copy an MCP config and give it to an AI tool of your own choice, which can then read the local database on that Mac read-only. This is entirely optional, off by default, and can only be set up by you on your Mac.
• If the AI tool you choose runs in the cloud (as most AI assistants do), the health data it reads may be sent to that AI provider and handled under that provider’s own privacy policy and terms. Which AI tool you use, and whether you connect one at all, is your choice; we are not the provider of those services and do not control how they handle data.
• Every time an AI tool reads your data, the Mac app records it in the local “Access Log” so you can review it at any time. You can remove HealthFold from your AI tool’s configuration, or uninstall the Mac app, whenever you like.
• The iPhone app itself never sends data to any AI service or other third party.

7. Update checks in the Mac app

Shortly after launch and roughly every 24 hours after that, the Mac app fetches https://deskfox.ai/healthfold/version.json to see whether a new version is available. This is an ordinary web request: as with visiting any website, our server sees your IP address and standard request information. The request contains no health data and no account or identity information.

When you tap a link in the apps, such as our website, the download page or this privacy policy, it opens our website in your browser as a normal web visit.

8. Deleting data and revoking access

• Delete data on your Mac: delete the member in the Mac app (“Delete and unpair”). The data moves to “Recently Deleted” and is permanently deleted after 30 days, or you can choose “Delete Permanently” there to remove it right away. Deleting the member also unpairs the iPhone, so it stops syncing to that Mac.
• Uninstall the Mac app: use “Uninstall HealthFold…” in the menu to stop and remove the background receiver and the MCP program, optionally deleting all health data on that Mac at the same time.
• Delete the iPhone app: deleting it removes the pairing details, sync progress and local log it kept on the iPhone. Your original data in the Health app is not affected.
• Revoke Health access: at any time, go to Settings > Health > Data Access & Devices > HealthFold on your iPhone and turn off some or all categories (the exact path may vary slightly by iOS version). Camera and Local Network access can be turned off in Settings > HealthFold.

Because we hold none of your health data, you delete, export or correct it directly on your own devices; there is nothing you need to request from us.

9. Health use

HealthFold helps you view and organize your own health records. It is not a medical device and does not provide diagnosis or treatment advice. Please consult a qualified professional about any health concern.

10. Children

HealthFold is not directed to children under 13 (or a higher minimum age where local law requires it). We do not knowingly process children’s personal information, and because we collect no data, we do not receive any.

11. Changes to this policy

If we update this policy, we will post the new version on this page and update the effective date at the top. If an update would materially change how data is handled (for example, if we were ever to start collecting any data), we will tell you clearly in the app or on our website in advance.

12. Contact us

If you have any questions about this policy or about privacy in HealthFold, please contact: lengjie@getbot.me

Developer: Lengjie (Beijing) Technology Co., Ltd. Website: https://deskfox.ai/healthfold/