Privacy Policy

Effective 26 August 2026

Calbook is a calorie and workout diary made by Cortexlumora Private Limited, a company registered in India (“Cortexlumora”, “we”, “us”). This policy explains what we collect when you use the Calbook app, why we collect it, who else touches it, and what you can ask us to do with it.

We do not run ads, we do not use third-party analytics or advertising SDKs, we do not track you across other apps or websites, and we do not sell or rent your data to anyone.

1. Information we collect

Account information

To create an account you give us an email address. Sign-in and account management are handled for us by Clerk, which stores your email address and authentication details (such as sign-in tokens and the times you signed in). We do not store your password.

The entries you log

Everything you record in the diary is stored against your account so the app can show it back to you:

Food entries — what you ate and the calories, carbohydrate, protein and fat worked out for it, including any corrections you make.
Exercise entries — the activity and the calories burned.
Weight entries — the weights you log and any target weight you set.
Water entries — the amounts you log.
The text of your messages — the sentences you type to log something or to ask a question about your own numbers.
Favourites and edits — meals you save to reuse, and adjustments you make to an entry.

Photos

If you attach a photo — a plate of food, a bathroom scale display, a treadmill or watch screen — the image is uploaded to Amazon Web Services (AWS) S3 for storage and sent to OpenAI so that a model can read what is in it and turn it into diary entries. Photos stay attached to the entry they created until you delete the entry or your account. Please do not attach photos containing anything you would not want processed this way.

Profile details

To estimate a daily calorie budget the app asks for your weight, height, age and sex. These are used for that calculation and to show your progress; they are not used for anything else.

Technical information

Our servers keep ordinary operational records — such as the time of a request, an error code, or an IP address — for keeping the service running and secure. We do not build advertising or behavioural profiles from them.

2. Why we use it

To run the diary — to save your entries and show your day, your macro rings, your weight trend, your weekly summary and your PDF reports.
To turn what you write or photograph into numbers — the text and images you submit are analysed so they can become calories, macros, calories burned, water or weight.
To answer questions from your own data — when you ask something like “how much protein have I had today?”, we read your entries to answer it.
To estimate your calorie budget — from the profile details you provide.
To keep your account secure and to identify you when you sign in.
To support you — if you email us, to answer your message.
To fix and improve the app — diagnosing errors and problems reported to us.

We rely on the necessity of processing your data to provide the service you asked for, on your consent where you choose to attach a photo or provide profile details, and on our legitimate interest in keeping the service working and secure.

3. Who else processes your data

We use a small number of service providers. They act on our instructions and may only use your data to provide their service to us.

Clerk — user accounts, sign-in and authentication (your email address and authentication details).
OpenAI — analysis of the text and photos you submit, so they can become diary entries or answers. OpenAI processes this as our API provider.
Amazon Web Services (AWS) — storage of the photos you attach, in S3.
Railway — hosting of our application server and database.

These providers may store or process data outside India, including in the United States. We may also disclose data if the law requires it, to enforce our Terms, or to protect the rights and safety of our users or of Cortexlumora. Beyond this, we do not share your data, and we never sell it.

4. How long we keep it

Your entries, photos and profile details are kept for as long as your account exists, because the app is a diary and its value is in the history. When you ask us to delete your account, we delete your account data — entries, photos and profile details — from our systems, and instruct our providers to do the same, within 30 days, except where we are required by law to keep something longer. Operational logs are kept for a short period and then discarded.

5. Your rights and choices

Access — you can ask for a copy of the data we hold about you. You can also export a PDF report for any date range from inside the app at any time.
Correction — you can edit or delete individual entries and adjust macros yourself in the app.
Deletion — you can ask us to delete your account and everything in it.
Objection and withdrawal of consent — you can stop attaching photos at any time, and you can stop using the app and ask us to delete your data.

To exercise any of these, email support@calbook.app from the address on your account. We will respond within a reasonable time and in any event as required by applicable law.

6. Security

Data is transmitted over encrypted connections and stored with reputable providers. Access to production systems is limited to people who need it. No system is perfectly secure, so we cannot guarantee absolute security, but we take reasonable steps to protect your information.

7. Children

Calbook is not intended for children under 13, and we do not knowingly collect data from them. If you believe a child under 13 has given us personal data, email us and we will delete it.

8. Changes to this policy

If we change this policy we will update the effective date at the top of this page and, where the change is significant, tell you in the app or by email. Continuing to use Calbook after a change means you accept the updated policy.

9. Contact

Cortexlumora Private Limited, India.
Email: support@calbook.app