Privacy

Math Stats 1 Drill, by Abel Minded. Last updated October 30, 2026.

The short version: your progress is kept in your browser. The game itself runs on our game server, so while you play, a copy of your progress is in that server's memory, and it's wiped when you leave. Your handwriting is read by Anthropic on your own key, which never reaches us. There are no accounts, no database of players, no analytics, no tracking cookies and no ads.

What stays on your device

Your progress, answer history, play habits, handwriting costs, settings and API key are kept in this browser's own storage, on this device. Your API key never leaves it except to go to Anthropic.

What leaves your device

Your game, while you play. The game runs on our game server, so the game's code stays on our side. When you open it, your browser sends a copy of your progress files (never your API key) to a game room that is yours alone for this visit; each click goes there, and what changed comes back to your browser. The room keeps your files only in memory. So that a server restart doesn't lose your place, it also notes where you are in this session (the questions so far and the one on screen) until you leave. All of it is wiped when you close the page, or 30 minutes after your last click. Nothing goes into a database or a log, and nothing ties one visit to the next.
Handwriting. When you press Check, your pen strokes go to your game room, which turns them into a picture and writes the request to read it. Your browser sends that request to Anthropic using your own API key, and hands what Anthropic read back to the room to grade. The key itself never reaches us. Anthropic's own terms and privacy policy cover that request.
Reports. Only when you press Send in the Report window: the question, your answer, how the handwriting was read, your note, a screenshot of the game (you can see it first), the build, and your screen size. Nothing that ties two reports to the same person or device. Never your name, email or API key. Reports are kept for 180 days, then deleted.
Error reports. Only when you press Send on the "Something went wrong" bar: the error, where it happened, the build, the question id and your browser's name. No install id, no screenshot. You can see exactly what is sent before you send it. Kept for 180 days, like reports.
Report history. To track fixes, we keep which question a report was about, its tags, the first part of its note and how it was resolved. The public bounty board shows only a question's name and whether it has open reports.
Limits. To keep the game server from being flooded, it counts calls per connection over the last minute (Cloudflare's rate limiting) and calls per day in total, with nothing about who made them. To stop floods of reports, the report service counts reports per connection for an hour, using a scrambled code it can't turn back into your address, and forgets it within a day.

Like every website, the site is delivered by a hosting company (Cloudflare), which handles your connection to deliver the pages. Video links on some concepts open other sites, which have their own policies.

Back up your progress

Because your progress lives only in this browser, clearing site data, a full disk, or Safari's rule of erasing a site's storage after 7 days without a visit can wipe it. Open My progress > Your habits and press Save a backup to download one file with your progress (never your API key). Load a backup puts it back, here or on another device. On Chrome or Edge on a computer you can turn on auto backup to a file, which rewrites that file after each session.

Your API key

Your key is used only to talk to Anthropic. You can tick Don't remember my key on this device so it's kept only until you close or reload the page, or press Forget my key to remove it.

Delete everything

My progress > Your habits > Delete everything on this device removes your progress, history, play stats, saved reports, settings and API key from this browser, after you confirm twice.