The short version: almost everything you write in Mentulis stays on your phone, and your conversations with the Companion are not stored anywhere at all.
Last updated: 5 September 2026
This is the whole picture, in one table.
| What | Where it is stored | Can we see it? |
|---|---|---|
| Mood check-ins | Your phone only | No |
| Journal, gratitude, worry entries | Your phone only | No |
| Self-check results (GAD-7, PHQ-9) | Your phone only | No |
| Thought records | Your phone only | No |
| Companion conversations | Nowhere — discarded after each reply | No |
| Your email and password | Firebase Authentication | Email yes, password no |
| Profile — name, country, province | Firebase Firestore | Yes |
In plain terms: we hold your account, not your contents. The things you would least want read — what you wrote at 2am, how you scored, what you have been worrying about — are on your device, and we have no copy of them.
When you send a message, it goes to our server, which passes it to the AI model that generates the reply. The reply comes back to you and the exchange is discarded. It is not written to a database, not saved to your phone, and not kept in a log.
This means there is no chat history to browse — and no chat history to be breached, requested by a court, or sold in an acquisition. We think that trade is worth it.
Along with your message we send the conversational tone you chose in Personalize (warm, direct or quiet). Nothing else about you is attached.
Signing in uses Firebase Authentication, a Google service. It holds your email address and a securely hashed password. We can see your email address; nobody, including us, can see your password.
If you fill in your name, country of origin or province, those are stored in Firebase Firestore under your account. They are optional — the app works without them — and they are used only to personalise what the app shows you.
You can turn on backup, which copies your on-device wellness data to the hidden app-data area of your own Google Drive. That copy lives in your Google account, not ours. We can only ever see the single file the app created — never anything else in your Drive — and the backup never passes through Mentulis servers.
It is off by default. If you never turn it on, nothing is ever copied anywhere.
These providers process data on our instructions in order to run the service. They are not permitted to use it for their own purposes.
All traffic between the app and our services is encrypted in transit using HTTPS/TLS. Data held in Firebase is encrypted at rest by Google.
No system is perfectly secure. The strongest protection here is structural rather than technical: most of your information is not in our custody in the first place.
Depending on where you live you may also have rights to access, correct or restrict use of your personal information, and to complain to a regulator. Write to hello@mentulis.com and we will help.
Mentulis is not intended for anyone under 16. We do not knowingly collect information from children. If you believe a child has created an account, email us and we will remove it.
mentulis.com sets no tracking cookies and runs no advertising or analytics scripts. Fonts are loaded from Google Fonts, which receives your IP address as part of serving them. The breathing exercise and mood check-in on the homepage run entirely in your browser and send nothing anywhere.
If we change this policy in a way that materially affects you, we will tell you in the app or by email before it takes effect.
Mentulis is not a medical service or an emergency service.
Nobody monitors what you write, and no one is watching for signs that you are in danger. If you are in crisis, contact your local emergency number or a crisis line.
Questions about privacy, or to exercise any of the rights above: hello@mentulis.com
See also our Terms of Use and Account deletion page.
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