Privacy Policy

Last updated: March 13, 2026

Zeriko ("we", "our", or "us") operates the language learning application at zeriko.org. This Privacy Policy explains how we collect, use, and protect your information when you use our service.

1. Information We Collect

• Account information: When you create an account, we collect your email address and an optional display name.
• Profile preferences: Language learning settings (target language, source language), persona details (name, age, gender — optional), politeness preference, and TTS mode.
• Conversation data: Chat messages exchanged with AI characters are temporarily processed via our AI provider (OpenAI) to generate responses. We store conversation history in your account so you can continue sessions across devices.
• Vocabulary data: Words and flashcards you save during your learning sessions.
• Usage data: App performance logs and error reports (no personally identifiable information), used to fix bugs and improve the service.

2. How We Use Your Information

• To provide and personalize the language learning experience.
• To enable cross-device sync of your progress and vocabulary.
• To process AI conversation requests on your behalf.
• To improve the quality and reliability of the service.
• To send account-related emails (e.g., password reset). We do not send marketing emails.

3. Third-Party Services

• Supabase — Authentication and database hosting. Your account data and conversation history are stored on Supabase infrastructure. See their privacy policy at supabase.com/privacy.
• OpenAI — AI conversation generation and text-to-speech. Messages you send are transmitted to OpenAI's API to generate AI responses. See their privacy policy at openai.com/privacy.

We do not sell your data to any third party.

4. Data Retention

Your data is retained for as long as your account is active. You may request deletion of your account and associated data at any time by contacting us (see below). Conversation data processed by OpenAI is subject to OpenAI's data retention policies.

5. Cookies & Local Storage

Zeriko uses browser localStorage to store your session token, language preferences, and cached vocabulary locally on your device. No third-party advertising cookies are used.

6. Children's Privacy

Zeriko is not directed at children under the age of 13. We do not knowingly collect personal data from children under 13. If you believe a child has provided us with personal information, please contact us and we will promptly delete it.

7. Security

All data is transmitted over HTTPS. Passwords are hashed and never stored in plain text. We use Supabase's Row-Level Security to ensure users can only access their own data.

8. Your Rights

• Access the data we hold about you.
• Request correction of inaccurate data.
• Request deletion of your account and data.
• Export your vocabulary and progress data via the "Export Data" option in the app.

9. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of significant changes by updating the "Last updated" date at the top of this page.

10. Contact Us

For questions about this Privacy Policy or to exercise your rights, contact us at: support@zeriko.org