Privacy notice
Last changed on 11 October 2026.
This notice says what Kaltov keeps, who else handles it, and how to get it out or have it removed. It describes what the product does today.
What Kaltov keeps about a student
A school or a parent sets a student up. A student does not open an account and needs no email to enter.
- A display name, chosen by the teacher or the parent.
- An email address and a phone number, when the adult who added the student entered them.
- A 4-digit PIN, kept as a salted hash and not as the number.
- The lines the student writes on the board, with the mark the step checker gave each one.
- Each practice answer, each hint that was shown, and the whiteboard as it stood when the answer was checked, scratch marks included.
- Messages the student writes to a teacher or a parent inside Kaltov.
- A note a teacher writes about the student.
- Failed tries to enter with a class code, with the id of the device that tried.
What Kaltov keeps about a principal, a teacher or a parent
- Your email address, your phone number, the name of your school or household, and a display name where one is set.
- Your role and the classes you teach.
- Notes you send from the Note page, and messages you write inside Kaltov.
- When you pay: the plan, its dates, and the ids and payment events Stripe sends. You enter the card on Stripe's page. The card number does not reach Kaltov.
- The email Kaltov sent you, and whether you asked it to stop or the address bounced.
- When you ask for a short guide: the email address, which guide, and the language. This does not open an account.
The parent math check
The check is taken with no sign-in. Kaltov keeps the child's grade, each answer as typed, how long each answer took, and whether an adult helped. It keeps a keyed hash of the network address the check came from, and not the address.
To show the result, Kaltov asks for the parent's email address and, if the parent wants, a nickname for the child.
A check that never reached the email step is removed seven days after its last answer.
A check with an email that no account took is removed thirty days after the email was given.
A check that an account took stays with that account until the account is deleted.
The removal runs once an hour.
The result email has a link that says the check was not yours. It deletes the check and stops mail to that address.
Product events
Kaltov counts a small set of product events, such as a demo opened, a button pressed, a step checked, a hint shown, a student added, an assignment published, a report opened, a checkout started.
Before an event is saved, any field named email, name, note, text, PIN or token is dropped. So is any value that holds an @ sign or is longer than 80 characters.
Who else handles the data
Kaltov runs on the services below.
- Railway hosts the site and the database, in Singapore.
- Supabase runs sign-in for adults and holds the adult's email address. A student has no Supabase account.
- Stripe takes payment and holds the payer's details and the card.
- Resend sends Kaltov's email. It receives the address and the message.
- OpenRouter, and the AI providers it passes a request to, word some of the tutor's sentences. They receive the equation, a code for the kind of mistake, the class's grade and age, wording a teacher already accepted, and counts over at least five students. They never receive a student's name, an id, or a sentence a student wrote. When the step checker cannot read a line, the line may be sent with its math kept and every other word replaced by a mark. Every request carries the setting that denies data collection.
- Langfuse, on a server Kaltov runs, keeps a record of each of those requests and its reply. It holds only what was sent.
- get.geojs.io: when the host does not say which country a visit comes from, Kaltov sends the visitor's network address to this service to choose between Hebrew and English.
Training
Today, Kaltov does not use anything a student or an adult writes to train AI.
Export and delete
Settings has a Download button. The file holds your email, display name, phone, role and school name, and one row for each student you can already see: the student's name, how many checked steps they wrote, how many were correct, the teacher's note, and how many practice answers they gave. A principal or a parent gets every student in the school or household. A teacher gets the students in their own classes.
The file does not hold the lines themselves, the whiteboard or the messages. Ask for those at the contact address.
Settings has Delete account. For a principal or a parent it cancels the subscription first. Then it removes the school or household: its classes, its students, the lines, practice answers, hints, whiteboards, notes and messages, the billing and event records Kaltov holds for it, and every math check given with your email address. You type the school's name to confirm.
For a teacher it removes the teacher's own membership and class assignments. The classes and the students stay with the school.
After a delete Kaltov keeps the id of the removed school and the date.
The delete does not reach your sign-in record at Supabase, what Stripe keeps about a payment, email already sent, the list of addresses that asked for no mail, a guide request, or the record of requests to AI providers. Write to the contact address about any of these.
Anything else
To ask what Kaltov holds, to correct it, or for anything this page does not cover, write to the address on the contact page.