Privacy Policy

Last updated: 13 August 2026

Luther is an app for everyday mental well-being. What you type into it is personal, so this page says plainly what we collect, who else sees it, where it lives and how to erase it. No legal padding.

Who is responsible

Luther is operated by Mikhail Dubrovskii IE, a sole proprietorship registered in Yerevan, Armenia. For anything in this policy, write to support@deeptalk.help.

What we collect

DataWhy
Your email address, or the account identifier from Google Sign-InTo create your account and let you sign back in
Optional profile: first name, age range, gender, and what brought you to the appOnly to make the AI's replies fit you. Every field can be skipped
Your conversations with the AI, including transcripts of voice messages and images generated in a chatTo show your chat history and give the AI the context of what you already said
Psychological test answers and results, mood check-ins, journal entries, completed exercises, programme progress, achievementsThese are the features themselves — your history, charts and weekly reflections are built from them
Subscription status and the Google Play purchase identifierTo unlock the paid tier and handle renewals and refunds
A push notification token, if you allow notificationsTo send the reminders you asked for
The IP address recorded when you accept the termsProof of consent, kept as a single timestamped record
Technical counters of AI usage: number of tokens, cost, response timeTo watch spend and reliability. These records contain no message text

What we do not do. We do not sell your data. We do not show ads. There is no advertising SDK and no third-party analytics in the app. We do not use your conversations to train AI models.

Voice and images

A voice message is sent for transcription and converted to text; the audio itself is not stored on our servers — only the resulting text, as part of the conversation. Images generated in a chat are stored on our own server and served from a link with a random, unguessable name.

Who else processes your data

To make the app work we pass some data to the services below. They act as processors on our behalf.

ServiceWhat it receivesWhere
Fireworks AIThe text of your messages and test answers, to generate replies and interpretationsUnited States
OpenAIVoice recordings for transcription, images you send for analysis, and some text generationUnited States
Google Play BillingPurchase and subscription dataGlobal
Firebase Cloud MessagingYour push token, when notifications are enabledGlobal
Email delivery providerYour email address and the sign-in code, when you sign in by emailDepends on provider

Where your data is stored

Our database, the application and stored images all run on a single server located in France, in the European Union. Sending messages to the AI services above means that text leaves the EU for the United States; there is no way to generate an AI reply without it. If you would rather not have your words processed in the US, please do not use the chat and test interpretation features.

How long we keep it

Your data stays until you delete it. There is no silent expiry and no archive we keep afterwards. When you erase your account, conversations, test results, mood entries, journal notes and stored images are deleted immediately and permanently. We keep only anonymised transaction records — required for accounting — and they no longer identify you.

How to delete your data

In the app: Profile → Settings → Delete account. It takes effect at once. Signing up again with the same address gives you a new, empty account — the old history does not come back.

Without installing the app, use the data deletion request page.

Your rights

You can ask us what we hold about you, request a copy, have it corrected, or have it deleted. Write to support@deeptalk.help and we will answer within 30 days. If you are in the EU or the UK and you believe we handled your data badly, you may complain to your national data protection authority.

Security

All traffic between the app and our servers is encrypted with TLS. Access to the server is restricted, and the database is not reachable from the internet. No system is perfectly secure, so please treat what you write in any app accordingly.

Children

Luther is for adults — 18 and over. We do not knowingly collect data from children. If you believe a child has created an account, write to us and we will delete it.

Luther is not medical care

Luther is a self-help tool. It is not therapy, it does not diagnose, and it is not a substitute for a doctor or a psychologist. It is not an emergency service. If you are in crisis or thinking about harming yourself, contact your local emergency number or a crisis helpline right away.

The psychological questionnaires in the app are screening instruments, not diagnoses. A result is a reason to talk to a professional, never a verdict.

Changes to this policy

If we change how we handle your data, we will update this page and the date at the top. Significant changes will be announced in the app.