Calvin has no accounts and does not sell, share, or advertise against your data. Your food log lives on your phone. Some features send specific data to Calvin's server, and this policy sets out exactly which.
Everything you log is stored on your device: food entries, calories, macros, weight, goals, recipes, groceries, and your history. Calvin has no user accounts, no sign-in, and no cloud copy of your log. Deleting the app deletes this data. You can export it as CSV at any time from Settings.
Calvin uses a server (a Cloudflare Worker) for four things: AI photo scanning, food and barcode lookups, verifying a Calvin Plus subscription, and the optional Google Health connection. Everything below describes what is sent and what is kept.
When you scan a meal photo with Calvin Plus, the photo is sent to Calvin's server and passed to Google's Gemini API, which returns the foods it recognizes. Google processes the image under its API terms.
The photo itself is not stored. Calvin keeps a one-way hash of it alongside the resulting food list for 24 hours, so retrying the same photo does not cost another scan. The hash cannot be turned back into your picture.
To make results match what you actually eat, Calvin also sends the names and per-serving nutrition of up to 30 of your most recently used saved foods with the request, so a recognized item can be matched to your own product and your own numbers. No other part of your log is sent, and this is only sent on Plus photo scans.
Searching for a food or scanning a barcode sends the search text or the barcode number to Calvin's server, which looks it up in a public USDA product database, and to Open Food Facts if nothing is found. These requests carry only the search text or barcode.
To confirm a Calvin Plus subscription and stop the AI scan endpoint being abused, Calvin sends Apple's App Attest device identifier and your App Store transaction identifier with each scan. Calvin stores daily scan counts against these identifiers. They identify a device and a subscription, not you by name.
If you connect Apple Health, Calvin reads activity, energy, and weight data to show trends and import weigh-ins. Apple Health data is read on your device, stays on your device, and is not sent to Calvin's server or anywhere else.
These connections are optional and off unless you turn them on. They work differently from Apple Health, because the data comes from the provider's servers rather than from your phone.
If you connect one, Calvin's server stores:
| Data | Kept |
|---|---|
| Access and refresh tokens for the provider you connected | Until you disconnect |
| Daily steps, active calories, distance, and weight (Google Health and Fitbit) | Until you disconnect |
| Workouts: name, start and end time, calories, and Whoop's strain score (Whoop and Hevy) | Until you disconnect |
This data is stored against your device identifier, not your name or email.
Disconnecting in Settings erases all of it. The stored tokens are deleted, every synced activity, weight, and workout row for your device is deleted, and where the provider supports it Calvin asks them to revoke the connection so the grant cannot be reused. Rows left behind by a connection that can no longer be reached are deleted on a schedule. Nothing is retained for later.
Calvin Plus subscriptions are processed entirely by Apple through the App Store. Calvin never sees your payment details.
Calvin has no analytics service, no advertising, no third-party trackers, and no data brokers. Calvin records daily totals of AI usage and cost to monitor spending. Those totals are aggregate numbers and are not tied to individual users.
Calvin uses Apple's on-device MetricKit for crash and performance diagnostics. These reports are handled by Apple's standard, opt-in mechanisms. Calvin operates no collection service of its own.
Deleting the app removes everything stored on your device. The only personal data Calvin's server ever holds is the connected-service data described above, and disconnecting erases it. If you want anything else removed, or want confirmation that it is gone, email the address below.
Questions? Email support@calvinhealth.com.