Privacy Policy
Last updated: June 2026
What this is
Lumen is an AI language-tutoring service. To make it work, we need to collect and process some data about you. This policy explains what we collect, why, and what your rights are. We try to keep this plain and honest — no legal padding.
What we collect
Account information
Your email address, a display name (if you set one), and the date you created your account. We use this to identify you and manage your subscription.
Voice recordings
During live practice sessions your voice is streamed in real time to our AI voice provider (ElevenLabs) for processing. We do not store your raw audio. Transcripts of what was said are retained as part of your session history so Lumen can track your progress and corrections over time.
Session and usage data
We record when sessions start and end, how many minutes were used, the vocabulary and corrections your tutor saved, any homework assigned, and your overall progress level. This is what powers your learning path.
Billing data
If you subscribe, the payment is handled by the store you bought from — Apple on iPhone and iPad, Google Play on Android, or Stripe on the web. We receive a customer or subscription identifier and your subscription status from them, but never see or store your card number.
How we use it
Everything we collect is used to provide the tutoring service — nothing else. Specifically:
- Running your live voice sessions and generating your tutor's responses
- Building and updating your personalised learning path
- Tracking vocabulary, corrections, and homework across sessions
- Managing your subscription and access
- Diagnosing and fixing problems with the service
We do not sell your data. We do not use it for advertising. We do not share it with third parties beyond what is necessary to run the service (see below).
Third-party AI providers
Lumen is built on top of several AI services. Your data passes through them as follows:
ElevenLabs
Handles the real-time voice conversation — your speech is streamed to ElevenLabs and the tutor's spoken responses are generated there. ElevenLabs processes audio under their own privacy policy.
Anthropic (Claude)
Used server-side for analysing your diagnostic session, generating your learning path, and looking up word definitions. Transcript excerpts are sent to Anthropic's API for this purpose.
Supabase
Our database and authentication provider. Your account data, session history, and learning progress are stored in Supabase (hosted on AWS infrastructure in the EU/US).
Data retention
We keep your data for as long as your account is active. Session transcripts and learning history are retained indefinitely to support your progress tracking — but you can request deletion at any time (see below). If you delete your account, we remove your personal data within 30 days.
Your rights
You can ask us to:
- Export a copy of your data
- Correct inaccurate information
- Delete your account and personal data
- Explain exactly what data we hold about you
To make any of these requests, email us at [email protected]. We will respond within 14 days.
Cookies and tracking
We use a session cookie to keep you logged in. We use Google Ads conversion tracking to measure how many people sign up after clicking an ad — this is anonymous aggregated data and does not identify you personally. We do not use tracking cookies for any other advertising or analytics purpose.
Changes to this policy
If we make material changes we'll notify you by email at least 14 days before they take effect. The updated date at the top of this page reflects the most recent version.
Contact
Questions about this policy? Email [email protected].