Episteme

Standard Edition

Privacy Policy for Episteme Standard

Last updated: May 22, 2026

This Privacy Policy explains how Episteme ("we", "us", or "our") handles information when you use the standard edition of Episteme. The standard edition includes Episteme distributed through Google Play, Episteme Pro features, Episteme for Windows Standard, and future official standard builds for other platforms that link to this policy.

Summary: Episteme is designed as an offline-first reader. Your books and documents stay on your device unless you choose a cloud, sync, account, feedback, purchase, or AI feature that needs network processing. We do not sell your personal information or use your documents to train our own AI models.

1. Information We Collect

Account information

If you sign in with Google, Google may provide your name, email address, profile picture, and a stable account identifier. We use this to authenticate you, display your account locally, restore purchases, manage Pro status, provide device management, and enable cloud-backed features. We store the minimum account information needed for those features, such as your user ID and email address.

Imported books, documents, and library data

Episteme lets you import and read your own files, including PDFs, EPUBs, office documents, comics, text files, and other supported formats. Your files, reading progress, bookmarks, annotations, shelves, tags, settings, and local library metadata are stored primarily on your device.

If you enable cloud sync, the app may sync book metadata, reading progress, bookmarks, annotations, shelves, device records, and related sync state through our cloud database. Book files may be uploaded to the app-specific hidden folder in your own Google Drive account. We do not use your library for advertising or sell it to anyone.

Purchases and credits

Purchases are processed by the platform store or billing provider, such as Google Play Billing on Android. We do not receive or store your full payment card details. We may receive purchase tokens, product identifiers, transaction status, and related verification data so that we can unlock Pro features, credit packs, and purchase restoration.

AI, cloud TTS, recap, dictionary, and summarization requests

When you intentionally use an AI or cloud text-to-speech feature, Episteme sends only the content needed to fulfill that request. Depending on the feature and file type, this may include selected text, a page or chapter excerpt, generated context, an image of the current page, prompt settings, language or voice settings, and usage metadata needed to meter credits or diagnose failures.

Episteme does not upload your entire library for AI requests. We do not use your personal documents to train our own AI models. Our backend may route requests through service providers such as Cloudflare and Google Gemini API. Provider logging, abuse monitoring, retention, and training rules are governed by their terms and your selected plan, where applicable.

Diagnostics and support

Some standard builds may use diagnostics such as crash reports, error logs, device model, operating system version, app version, installation identifiers, and performance information to maintain and improve the app. If you contact support or send feedback, we collect the information you choose to send, including your email address, message, screenshots, and attachments.

2. How We Use Information

  • To provide reading, import, search, annotation, library, and customization features.
  • To authenticate accounts, verify purchases, manage credits, and restore Pro access.
  • To provide optional cloud sync, device management, and cross-device continuity.
  • To process user-initiated AI, cloud TTS, recap, dictionary, and summarization requests.
  • To secure the service, prevent abuse, debug crashes, and improve reliability.
  • To respond to support, feedback, legal, and account deletion requests.
  • To comply with applicable laws, platform policies, and provider requirements.

3. Google Account and Google API Data

When Episteme uses Google Sign-In, Google Drive, Firebase, Google Play Billing, or related Google APIs, our use of Google user data is limited to the features described in this policy and in the app. We request only the permissions needed for user-facing features, such as sign-in and app-specific Drive sync. We do not transfer or sell Google user data for advertising, credit-worthiness, or unrelated purposes.

4. Third-Party Service Providers

We use third-party providers to operate parts of the standard edition. Depending on your platform and enabled features, these may include:

  • Google Sign-In and Firebase: account authentication, cloud database, messaging, remote configuration, storage, and crash diagnostics.
  • Google Drive API: syncing book files to the app-specific hidden folder in your Google Drive account when you enable Drive-backed sync.
  • Google Play Billing or other platform billing providers: purchase processing and purchase restoration.
  • Cloudflare Workers: backend routing, purchase verification, feedback, and AI request mediation.
  • Google Gemini API and other AI providers: user-initiated AI, recap, dictionary, summarization, and cloud TTS features.
  • Email and support tools: responding to messages you send us.

These providers process information under their own terms and privacy policies. We try to send the minimum information needed for the feature you request.

5. Bring Your Own Key and Provider-Selected AI

If a standard build offers bring-your-own-key AI settings, the API keys you enter are stored locally on your device where possible, using platform-provided secure storage when available. Requests made with your key are sent to the provider you choose and are governed by that provider's terms, pricing, retention, and data-use practices. You are responsible for the keys, costs, quotas, and account terms associated with your provider account.

6. How Long We Keep Information

  • Local app data remains on your device until you delete it, clear app storage, or uninstall the app.
  • Account, sync, device, and purchase verification records are kept while your account is active or as needed to provide purchases, sync, support, security, and legal compliance.
  • Synced book files stored in your Google Drive appDataFolder remain in your Google Drive account until deleted through the app or through Google account tools that expose that data.
  • Support emails and feedback are kept as long as reasonably needed to respond, investigate issues, and maintain records.
  • Provider-side logs for AI, billing, diagnostics, and cloud services are controlled by the relevant provider's terms and settings.

7. Your Choices and Controls

  • You can use core reading features without enabling cloud sync or AI features.
  • You can disable sync and delete synced data from inside the app where the feature is available.
  • You can remove local files, clear app data, uninstall the app, or delete locally stored AI keys.
  • You can contact us to request account deletion or assistance with personal data requests.
  • You can manage Google account permissions, Drive data, purchases, and billing through Google's account and platform tools.

8. Security

We use reasonable technical and organizational measures to protect information, including HTTPS for network requests and platform security features for local storage where available. No method of transmission or storage is perfectly secure. You are responsible for keeping your device, Google account, provider accounts, and API keys secure.

9. Children

Episteme is not directed to children under 13. We do not knowingly collect personal information from children under 13. Account and cloud features may have higher age requirements depending on your region, platform, and provider terms.

10. International Processing

We and our providers may process information in countries other than where you live. Where required, we rely on appropriate legal bases and safeguards for this processing.

11. Your Privacy Rights

Depending on your location, you may have rights to access, correct, delete, export, or object to certain processing of your personal information. To make a request, contact us at epistemereader@gmail.com. We may need to verify your identity before acting on a request.

12. Changes to This Policy

We may update this Privacy Policy from time to time. The latest version will be posted on this page with an updated date. If we make material changes, we will provide notice where required by law or platform policy.

13. Contact

Questions or requests can be sent to epistemereader@gmail.com.