About this course

Kay made this course at Kaylum AI. Kay posts about AI on TikTok as @kaylumai.

The course grew out of the comments under Kay’s video about x402 on 1 October 2026. People asked for a plain explanation and a real example, and some doubted the numbers. The lessons answer those questions.

Every figure in the course shows the date it was checked and where it came from. Tap the date beside a number to see its source.

Figures that change often, like prices, limits and who supports what, are kept in one list. A program reads their source pages every day and flags any page that changed. Once a week, and every day while something is flagged, a routine checks those sources again and updates the figure. Each change is listed with its date on What’s new.

The live numbers, such as payments on Base, come from x402scan and Coinbase’s Bazaar, and each one shows when it was taken.

If something here is wrong, please say so. A wrong number counts, and so does a misread source or a fair point the course leaves out.

Open an issue on the research repository, or comment under one of Kay’s videos. Say what’s wrong and where you saw the right figure.

We check it against the original source, not against the course. When a lesson is fixed, its first screen says so, with the date and what changed, and the fix is listed on What’s new.

Every number, date and named claim comes from a research report on x402 and the projects building on Base, with its working notes. Both are public at github.com/kaylum54/x402-base-research.

Where sources disagree, the lessons say so and say which one they use. When a figure can’t be checked, it’s left out rather than guessed.