x402 lets a program pay a website a tiny price each time it asks for something.
Have something AI agents can’t get free? They can pay your site for it.
Start lesson 1Free and no sign-up. 17 short lessons, a little over 2 hours.
You already know 404.
Open a page that doesn’t exist and the website answers 404 Not Found. Every answer a website sends starts with a number like that.
402 means Payment Required. The web’s rules have called it “reserved for future use” since 1997. x402 gives it a job: a price that software can read and pay.
What happens, in four moves.
A program asks a website for the latest rainfall reading.
The website answers with a price: $0.001.
The program pays in USDC, a digital dollar, and a payment checker makes sure the payment is good.
The reading comes back, with a receipt.
The program never opens an account or fills in a card form.
What would people pay for?
Ideas from the comments, and one real seller, with a price for each ask.
Messy data, made clean
Council planning notices come as scanned PDFs. A builder’s program pays for your clean list instead of reading every file.
A hobby guide
People read it free, and AI bots that say who they are pay a tiny fee. Expect one payment per bot, since a bot only needs to read it once.
A tool that does one job
Cred Protocol sells wallet credit scores to programs for $0.01. From January to October 2026 it took $0.88 in total, so a good tool still needs buyers.
Who pays, and why would they?
The program’s owner pays.
They put money in the program’s wallet and set limits, such as $0.05 per call and $5.00 per session in Coinbase’s example (14 Oct). The program spends inside them without asking each time.
A program pays only when paying beats free.
Fresher, cleaner, allowed to use or quicker to get. If nothing beats the free version, a well-built program uses the free one.
The honest numbers.
about $23,000 a day
paid through x402 on Base on an average day in the 30 days to 14 October 2026. Tens of thousands of dollars a day, not millions.
Source: x402scan
Of every $10, about $2.70 looks like real buying: many buyers paying a seller for a service. Counting every unclear payment as real, it is $4.90 at most. Most of the rest goes round between the same wallets.
Base dollars from 11 April to 11 October 2026. Source: the course’s research.
Our last check, at 1pm UK time on 14 October, caught 40 payments in 38 seconds. 21 of them were under a cent.
17 short lessons, in three parts.
Each one takes 6 to 15 minutes. Lesson 1 needs no account.
Made by Kay at Kaylum AI, from public sources and on-chain data checked on 14 October 2026.