Personal Data Protection Notice

This notice is prepared by KYCEL INC (Delaware, USA - "Derso"), operator of derso.ai, as data controller under applicable personal data protection law.

Personal data we process

• Identity and contact: name and email address.
• Account and usage: lesson progress, study sessions, exam results, and quota usage.
• When you use voice questions, your audio is transcribed; the recording is not stored permanently, while the transcript is kept in question history.
• When you pay: transaction information through Stripe; card details do not reach us.
• Technical: session cookies, IP address, and device/browser information.

Purposes

• Providing the service: playback, progress saving, Q&A, and study sessions.
• Account security and authentication.
• Quota and subscription management, including billing.
• Measuring and improving service quality using aggregated analytics.
• Meeting legal obligations.

Transfers

Your data may be shared with service providers as needed: hosting (Railway), AI models, voice synthesis (ElevenLabs), and payments (Stripe). Provider servers may be outside your country.

Retention

Your data is kept while your account is active. When you delete your account, learning data is irreversibly deleted; invoices that must be retained by law are kept for the required period.

Your rights

You can request access, correction, deletion, objection to processing, and transfer information. You can delete your account in the app from Account -> Delete my account; for other requests, contact [email protected].

EU/EEA users (GDPR)

If you access the service from the EU/EEA, our processing relies on GDPR Art. 6(1)(b) performance of contract, Art. 6(1)(c) legal obligation, and Art. 6(1)(f) legitimate interest; analytics cookies run only with your explicit consent (Art. 6(1)(a)). You may exercise your rights of access, rectification, erasure, restriction, portability, and objection under Arts. 15-21 via [email protected], and you retain the right to lodge a complaint with your local supervisory authority.