Previa Privacy Policy
Effective Date: April 30, 2026 Last Updated: October 19, 2026
Previa (“the App”) is a pre-visit symptom checker that helps you prepare for medical appointments. This Privacy Policy explains what information the App collects, how it is used, and how it is protected.
1. Information We Collect
1.1 Information You Provide
- Profile data — first name, age, biological sex, known medical conditions, and current medications. This information is stored on your device, synced to your private iCloud (see Section 3.5), and used to personalize the App experience and improve symptom analysis.
- Symptom descriptions — free-text descriptions of your symptoms entered during a session.
- Session data — confirmed symptoms, selected suggested symptoms, custom symptoms you add, AI-generated summaries, and tests to discuss with your doctor.
- Recipient records — names, dates, and language codes of people you have shared session results with (e.g., “Dr. Smith, April 15, 2026, en”). These are stored on your device and synced to your private iCloud, for your reference only.
- Report PDFs — PDF versions of your session reports (original language and translations), generated and stored on your device and synced to your private iCloud.
- Test result documents — the photos or PDFs of lab or imaging reports you import into the Test Results feature. The original files are copied into the App, stored on your device, and synced to your private iCloud.
- Test result explanations — for each imported test, the AI-generated plain-language explanation, category, the date the test was performed, the date Previa produced the explanation, and the generated report PDFs (original language and translations).
1.2 Information Collected Automatically
- Language preference — your selected app language and report translation languages (stored on your device and synced via your iCloud profile).
- Biometric authentication events — the App uses Face ID, Touch ID, or device passcode to verify your identity. Biometric data is processed entirely by your device’s operating system (Apple’s LocalAuthentication framework). Previa never receives, stores, or transmits your biometric data.
1.3 Purchase Information
- Credit balance — the number of remaining credits (a single balance shared by symptom sessions and test explanations) is stored on your device as part of your patient profile and synced to your private iCloud.
- In-app purchase transactions — all purchases are processed by Apple through the App Store. We do not collect, store, or have access to your payment method, billing address, or Apple ID. We only receive a confirmation from Apple that a transaction was completed, which we use to add the corresponding number of credits to your balance.
- Free credits (anti-abuse) — new and upgrading users
receive two free credits, once. To prevent them from being claimed again
by reinstalling the App or on another device, the App records that the
grant has happened in two places:
- Apple DeviceCheck — the App obtains a temporary, encrypted token from Apple and sends it to our grant server (a Cloudflare Worker, separate from the AI proxy). The server uses it to read and set a single yes/no flag that Apple keeps for this device. Nothing else is sent with the token; our server does not store or log it, and it cannot be used to identify you or track your device. DeviceCheck exposes no stable device identifier and no personal information.
- Your private iCloud database — if you are signed into iCloud, a matching flag, so other devices signed into the same Apple Account do not receive the grant again.
1.4 Information We Do Not Collect
- We do not collect your location, contacts, or browsing history, and we do not access your photo library. Only the files you choose to import into Test Results are used (see Section 2.5).
- We do not use advertising identifiers or tracking pixels.
- We do not create user accounts or require email addresses.
- We do not access Apple Health (HealthKit) data in the current version of the App.
2. How We Use Your Information
2.1 Symptom Analysis
When you run a session, the following information is sent to our secure backend proxy server:
- Your symptom description (free text entered in Step 1)
- Selected and custom symptoms (in Step 2)
- Your clinical profile context — age, biological sex, known conditions, and current medications — for whichever of those you filled in
- Your selected language
This information is forwarded to Anthropic’s Claude AI service for analysis. The AI returns structured symptom suggestions and tests to discuss.
Why the profile is included. Age, conditions, and medications change what is worth investigating for the same reported symptoms — a cough in someone taking an ACE inhibitor, or abdominal pain at 25 versus 70, warrant different tests. Sending this context is what lets Previa tailor suggestions rather than treat every patient identically.
Your name is never sent. Neither are your recipient records or purchase history. Every profile field is optional, and only fields you actually fill in are sent: an unset age, a biological sex of “Prefer not to say”, and empty condition or medication lists are all omitted. Leaving a Profile field blank is how you opt out — nothing is inferred or filled in on your behalf, and you can clear any field at any time.
2.2 Translate Report
When you translate a session report, the following information is sent to the same secure backend proxy server:
- The session’s symptom list, tests to discuss, and AI summary
- The personal details recorded with the session (age, biological sex, known conditions, current medications), so the translated report carries the same context as the original
- The formatted report text in the original language
- The target translation language
Your first name is never sent for translation. Names are not translated, so it is composed into the translated report on your device and never leaves it. Condition names are translated; medication names are left exactly as written, since drug names are not translated between languages.
The AI translates the report and returns the translated text. The same privacy protections apply as for symptom analysis — no personal information beyond the session content and the recorded personal details is transmitted, and our proxy server retains no data after the request is processed (for Anthropic’s handling, see Section 3.4).
2.3 Personalization
Your first name is used only on your device, to personalize the greeting on the Home screen; it is never sent anywhere. Your age, biological sex, known conditions, and current medications are included in AI analysis requests as described in Sections 2.1 and 2.5, so that suggestions and explanations reflect your clinical situation.
2.4 History
Session results and PDF reports (original and translated) are stored on your device and synced via your private iCloud (see Section 3.5) so you can review past sessions and share results with healthcare providers.
2.5 Test Results Analysis
When you import a test into the Test Results feature, the imported document(s) — the actual photo or PDF, not just extracted text — are sent to our secure backend proxy server and forwarded to Anthropic’s Claude AI service: first to check that the document is a readable test result, and then to produce a plain-language explanation. Your clinical profile context (age, biological sex, known conditions, current medications) is sent with the explanation request, for the same reason as in Section 2.1: reference ranges and the significance of a value can depend on age, sex, an existing condition, or a medication you take.
What the analysis uses. Previa reads the test values, the test name, and the date the test was performed. Personal details printed on the report — your name, date of birth, or ID and account numbers — are not used in the analysis and are not extracted or stored as separate data.
You decide what to include. Because the document image is transmitted as-is, anything printed on it is sent along with it. If you would rather not transmit the identifying details on your report, you can cover or crop them before importing; the explanation does not depend on them. (Cropping out the dates will simply show them as “N/A”.) The app repeats this note on the import screen.
As with symptom analysis, the proxy server does not store or retain the document after the request is processed, and Anthropic does not use API inputs or outputs to train its models (see Section 3.4).
3. Data Storage and Security
3.1 Local Storage
All personal data is stored on your device using Apple’s SwiftData
framework with file protection encryption
(.fileProtectionComplete). This means your data is
encrypted at rest and is only accessible when your device is
unlocked.
3.2 Biometric Protection
The App requires Face ID, Touch ID, or device passcode authentication every time it is opened. This cannot be disabled. You can configure the lock timing (immediately, after 1 minute, or after 5 minutes) in Settings.
3.3 Backend Proxy Server
The App does not communicate directly with Anthropic’s AI service. All API requests are routed through a secure backend proxy server hosted on Cloudflare Workers. The proxy server:
- Holds the API key for the AI service (never embedded in the App)
- Forwards your symptom data to Anthropic’s Claude API for processing
- Returns the AI response to your device
- Does not store, log, or retain your symptom data after the request is processed
- Does not associate requests with your identity
3.4 Anthropic’s Data Handling
Data sent to Anthropic’s Claude API — the requests described in Section 2 and the AI’s responses — is processed in accordance with Anthropic’s Usage Policy and Privacy Policy. Anthropic’s security measures and compliance certifications are described in its Trust Center.
- No training. Anthropic does not use API inputs or outputs to train its models.
- Limited retention. Anthropic automatically deletes API inputs and outputs within 30 days. A request flagged by Anthropic’s safety systems may be kept longer for safety review, and data may be retained where the law requires it (Anthropic’s retention details).
- No link to you. Requests reach Anthropic from our proxy server, not from your device, and carry no account, name, or device identifier. An imported test document contains whatever is printed on it (see Section 2.5).
3.5 Cloud Sync (iCloud)
Your App data syncs across your Apple devices through your private iCloud database using Apple’s CloudKit, so your profile, sessions, test results, report PDFs, credit balance, and app settings are available on each device signed into the same Apple Account.
- Sync uses your iCloud account — there is no Previa account and no Previa-operated copy of your data. Your data resides in your private iCloud database, governed by Apple’s Privacy Policy and iCloud terms.
- Data in iCloud is encrypted in transit and at rest by Apple.
- Deleting data on one device (see Section 5.1) removes it from iCloud and from your other devices.
- Your data is stored in the private database, not a shared or public one — it is not accessible to us or to other users.
- If you are not signed into iCloud, the App works fully on that device and sync is simply idle until you sign in.
4. Data Sharing
We do not sell, rent, or share your personal information with third parties for marketing or advertising purposes.
Your data is shared only in the following circumstances:
- AI analysis — anonymized symptom text and the Profile context you have filled in (age, biological sex, known conditions, current medications) are sent to Anthropic’s Claude API via our proxy server, as described in Section 2.1. Your first name is never sent.
- AI translation — session report content is sent to Anthropic’s Claude API via our proxy server for translation, as described in Section 2.2.
- Test Results analysis — imported test documents are sent to Anthropic’s Claude API via our proxy server to be read and explained, as described in Section 2.5.
- iCloud sync — your App data is stored in your own private iCloud database via Apple’s CloudKit so it can sync across your devices, as described in Section 3.5. This is your personal iCloud storage; we do not receive a copy.
- In-app purchases — purchase transactions are processed by Apple. We do not transmit any purchase or payment information to our servers or any third party. See Apple’s Privacy Policy for details on how Apple handles purchase data.
- Your explicit sharing — when you use the Share feature to send session or test report PDFs (original or translated) to a healthcare provider or other recipient via Messages, Mail, AirDrop, or other apps you choose. These reports include a Personal Details section listing the age, biological sex, conditions and medications recorded with that record, and your first name if you have set one, so the recipient can see what the information was based on. If you would rather share a report without your name, clear the name in your Profile before generating it.
5. Your Rights and Controls
5.1 Data Deletion
You can delete your data at any time from the Settings screen:
- Delete all sessions — permanently removes all session history, including symptoms, tests to discuss, and recipient records.
- Delete all tests — permanently removes all imported test results, including the original documents, explanations, and generated report PDFs.
- Reset Profile — clears your profile data (name, age, biological sex, conditions, medications). Your credit balance, purchase history and app settings are not part of your profile data and are kept, so resetting cannot destroy credits you have paid for.
These actions cannot be undone. Because your data syncs via iCloud, deletions also propagate to your other devices signed into the same Apple Account.
To remove all of your Previa data from iCloud at once, go to Settings ▸ [your name] ▸ iCloud ▸ Manage Storage ▸ Previa and choose Delete Data. This also removes your credit balance, including purchased credits, and cannot be undone.
Saved sessions and test results keep their own copy of the Profile details that were used to produce them (age, biological sex, conditions, medications, and your first name if set), recorded at the time of saving. This is what allows a report to remain an accurate record of the information you were given and why. Resetting your Profile does not alter records already saved; to remove those details, delete the sessions or test results themselves.
5.2 Data Portability
You can share any session report as a PDF file using the system share sheet, including translated versions. This allows you to keep a copy of your data outside the App.
5.3 No Account Required
Previa does not require you to create an account, provide an email address, or sign in. There is no server-side user profile to manage. Cross-device sync uses your own Apple Account (iCloud), not a Previa account.
6. Children’s Privacy
Previa is not directed at children under the age of 13. We do not knowingly collect personal information from children. The App is intended for adults preparing for medical appointments or caregivers managing health information for family members.
7. Changes to This Policy
We may update this Privacy Policy from time to time. The “Last Updated” date at the top of this page reflects the most recent revision. Continued use of the App after changes are posted constitutes acceptance of the updated policy.
8. Contact Us
If you have questions or concerns about this Privacy Policy or the App’s data practices, please contact:
Email: previa@okdk7.com
9. Summary
| What | Details |
|---|---|
| Data stored on device & synced to your private iCloud | Profile, sessions, symptoms, tests to discuss, PDF reports, recipient records, test results & imported documents, credit balance, app settings |
| Data sent to server | Symptom text, profile context you filled in (age, biological sex, conditions, medications), language preference, report content and personal details for translation, imported test documents (Test Results), a temporary DeviceCheck token (free-credit check) |
| Data NOT sent to server | Your name — never, for analysis or translation — plus recipient records, purchase history, payment details. Blank profile fields are omitted; leaving a field empty is the opt-out |
| What a shared report contains | Personal details (age, sex, conditions, medications, and your name if set), symptoms, AI summary, tests to discuss, disclaimer |
| Server data retention | Our servers: none — requests are processed and not stored. Anthropic: deleted within 30 days (longer only if flagged for safety review) and never used for training — see Section 3.4 |
| Cloud sync | Your private iCloud database (Apple CloudKit); no Previa server copy |
| Anti-abuse | Apple DeviceCheck per-device flag + a flag in your private iCloud, recording only that the free credits were granted; no PII, no tracking identifier |
| Encryption | iOS file protection on device; iCloud data encrypted by Apple in transit and at rest |
| Authentication | Face ID / Touch ID / Passcode (required, cannot be disabled) |
| Third-party analytics | None |
| Advertising | None |
| Account required | No (cross-device sync uses your Apple ID / iCloud) |