Privacy
Mat Log is a training log, open to anyone with a Google account. This page says what happens to a Session after you save it, in plain terms. It is short because the answer is short.
What is stored
The text you write, exactly as you wrote it, with the date you saved it. Mat Log never edits, reformats, or corrects that text. Everything else the app shows you, the Positions, the submissions, how your body felt, is derived from that text by a model afterwards and can be thrown away and rebuilt at any time. The text is the record. The structure is an index over it.
That text is sent to a server so it is not lost if you lose your phone. The database is hosted by Neon and the app by Vercel, the way any web app is hosted. A copy is also kept on the phone so the log opens with no signal.
Who reads it
By default, no one. Your Sessions are private to your account. No other account can see them, and the author of Mat Log does not read them. The author does run the database, as the person running any web app does.
One automated exception. The text of a Session is sent to Anthropic, the company whose Claude models turn the prose into structure: when you save it, and again whenever the way the structure is derived changes, so the index can be rebuilt. Only the text goes, not your name, your account, or the date. A Session much longer than a normal training note is stored but not sent. Anthropic handles what it receives under its own terms.
Not built yet, and said here so you know it is coming. After you have written a few Sessions, the app will ask you once whether the author may read your log to improve how well the structure gets derived. It will be a yes or a no, it will cover your whole log including what you wrote before, and you will be able to take it back later, at which point your log leaves that set. Until it is asked and you say yes, nothing changes, and saying no will cost you nothing in the app.
What is never done
- Your Sessions are never published, quoted, or shown to anyone else.
- If you do let the author read your log, that is for scoring how well the model reads it, and nothing more. It is never discussed with you, and the copy read for scoring is deleted when the test ends.
- The people you name in a Session, the people you train with, coaches, whoever, did not agree to any of this. That is exactly why the read set can never be published.
- Nothing is sold, and there is no advertising.
Your account
You sign in with Google, and any Google account will do. Signing in for the first time is what creates your account. Sign-in is handled by Clerk, an authentication service. There is no password here at all. Mat Log's own database holds the identifier Clerk gives it for your account and your Sessions. It does not hold your email address, which Clerk keeps.
On your phone
The phone keeps a copy of your log so it opens without signal, and a queue of anything you saved that has not reached the server yet. Signing out forgets the copy of the log. A Session you wrote but that has not been sent is kept until it is sent, because a Session is never lost, and it is sent to the account that wrote it.
One thing the phone can get wrong. If a sign-in lapses while the phone has no signal, it cannot check, and it keeps showing the last account's log until it can. On a phone only you use, that is your own log.
Deleting a Session
Deleting a Session removes it from your log and from every view, on the phone and on the server. The server keeps the deleted Session marked as deleted rather than erasing it, so that a rebuild of the structure knows to skip it and so that deleting does not make room for more than the day's allowance of Sessions. There is no button that erases one entirely. If that matters to you, ask.
Questions
Ask the author. Most people arrive here because the author, or someone the author showed it to, pointed them at it, so you already know how to reach them. The author would rather hear the question than have you stop writing.