Privacy Policy

1. Introduction

Lexula ("we", "our", or "us") values your privacy and is committed to protecting your personal data. This Privacy Policy explains how we collect, use, store, and disclose information when you access or use our web application, Telegram Mini App, and associated reading and vocabulary learning services.

2. What Information We Collect

We collect information necessary to deliver and personalize your reading experience:

• Account Information: When you register, we collect your name, email address, password hash, or your Telegram identifier (if you choose to sign in via Telegram).
• Uploaded Books & Documents: Books (EPUB, FB2, TXT, PDF) that you upload into your personal library. These are stored securely in your private account and are only accessible by you.
• Learning & Progress Data: Current reading position, completed pages, words saved to your personal vocabulary, and spaced repetition review histories (SM-2 intervals and ratings).
• Technical & Log Data: Device type, browser user-agent, anonymized IP addresses, and operational error logs to diagnose issues and ensure application reliability.

3. How We Use Your Information

We use your information solely for the following purposes:

• To provide, maintain, and personalize the Lexula reading and spaced-repetition learning platform;
• To synchronize your reading progress and saved vocabulary across all your devices;
• To generate contextual AI translations and grammar explanations for words and phrases you query;
• To manage your subscription status and authenticate access;
• To prevent fraud, security incidents, and abuse of the Service.

4. AI Processing and Third-Party Sub-processors

When you click a word or sentence for translation, Lexula sends only the minimal relevant text snippet (the word and its surrounding sentence context) to our secure AI inference providers (such as OpenAI or Anthropic).

Zero Model Training: Your private book texts and requested hints are processed via commercial enterprise APIs that strictly prohibit using customer data for training public foundation models. We never transmit entire book files to third-party AI providers.

5. Payments and Telegram Stars

Subscriptions and digital upgrades are processed directly through Telegram Stars. Lexula does not collect, receive, or store credit card numbers, bank account numbers, or payment billing addresses. Payment confirmation and fulfillment are handled securely via cryptographic Telegram webhooks.

6. Data Retention and Complete Account Deletion

We retain your data only for as long as your account remains active. You maintain total control over your information:

• Book Deletion: You can delete any book at any time from your library. Deleting a book removes its text, pages, and cached segments.
• Account Deletion: You can permanently delete your entire account in your Profile settings. Account deletion immediately and irreversibly cascades to remove your profile, personal library, uploaded files, saved vocabulary items, review states, active sessions, and payment records.

7. Cookies and Local Storage

We use minimal cookies and browser local storage strictly for functional purposes: maintaining your authenticated session, remembering your preferred interface language, and caching offline reader progress to avoid data loss. We do not use third-party cross-site advertising trackers.

8. Your Rights (GDPR / CCPA)

Depending on your location, you have rights regarding your personal information, including the right to access, rectify, export, or request the deletion of your personal data. To exercise any of these rights, you can utilize the self-service tools in your account profile or contact our team directly.

9. Contact Us

If you have any questions or privacy inquiries, please reach out through our Feedback & Support Form.