Privacy

Last updated 12 November 2026. This page lists what this site keeps about you, where it lives and how to remove it.

Your email

We do not store your email address as plain text. When you sign in, a one-way function turns it into a scrambled string.

If you pay on Substack, our plan list holds that scrambled string and your plan. It holds nothing else about you. A free account is not on the list.

Someone who already knows your address could run the same function and find the match. That is the limit of this protection.

Signing in with Google

You sign in with Continue with Google. Google tells us your email address and whether Google has confirmed it. We ask for nothing else: no password, no contacts, no files. The address is scrambled and checked against the plan list.

To stop abuse, we count sign-in attempts for up to 24 hours. The count uses a scrambled form of your IP address.

While you are on Google's page, a cookie named mua_google holds one-time check values for up to 10 minutes. It is removed when you come back.

Payment

You pay on Substack. This site never sees your card. We read a subscriber list exported from Substack and keep only the scrambled email and the plan of paying members.

What you do on the site

Each signed-in account gets a member number, such as Member ABC123. It is worked out from the scrambled email with a private value, so it cannot be traced back to your address by outsiders. These stay on our server under that number:

Leaderboard: your member number, the name you typed if you added one, whether you show it, whether you hide from the board, your XP, your level, how many entries you finished, and the date of the last update. XP, level and finished entries are reported by your browser. Anyone who opens the Leaderboard sees your nickname or chosen name, XP, level and finished entries, unless you hide from the board.
Done wall: your post, the entry you picked, the date and the name you post under. Anyone who opens the Done wall sees these.
Skill maker: how many skills you made this month. Your answers go to our server to build the file. The server does not save them.
Ask the Toolbox: your question goes to our server to search the entries. The server does not save it.
Start week, for Founding members: your line for each day, the date and the name you post under. Other Founding members see these.
Founding wall: your nickname, your real name if you add it, whether you show it, and the month you joined. Anyone can see the name you choose to show.

In your browser

A cookie named mua_session keeps you signed in for 30 days. It holds the scrambled email, a shortened form of your address such as ab***@example.com, an end date and a random number for this sign-in. It is signed, so it cannot be changed, and scripts on the page cannot read it. Signing out removes it and blocks it on our server, so a copy of it stops working too. Sign out on every device, on your Account page, does the same for all of them.

These stay in your browser's storage: My desk, your About me page, saved and finished entries, the steps you ticked, your filled-in versions, your four-week plan answers, the skills on your shelf and your theme. Your name settings are there too, and the leaderboard copy of them goes to our server. Signing out does not clear this storage. Clearing your browser's site data does.

There are no ads, no analytics and no tracking cookies on this site.

Our server

The site runs on Vercel. What it keeps (the plan list, the walls, the leaderboard, sign-in counts and the sign-out list) is stored in a database run by Upstash. Both companies keep their own technical logs, which can include IP addresses.

Removing your data

On your Account page, Delete my data on this site removes your leaderboard row, your Done wall posts, your Start week lines, your Founding wall name and your skill maker count, and signs you out everywhere. It cannot be undone.

You can also leave the leaderboard on the Leaderboard page, and Founding members can take their name off the Founding wall on the AI Club page.

A paid plan stays on the list while it is active on Substack. For anything else, write to me on Substack.