I run an x402 store where the customers are AI agents. In August I pointed a free checker at every host on the public x402 discovery list. One of them tried to sign its offers. Its signatures did not parse. x402 is the HTTP 402 payment flow Coinbase and Cloudflare revived for agents: request a resource, get a 402 with the price and the address, pay, retry. It works. Thousands of settlements a day go through it. What it does not do, by default, is commit the seller to anything bef...