Great reminder! I've been busy these past few days and didn't get a chance to verify. Took some time today to play around with the related materials: https://www.((coinbase.com))/zh-cn/developer-platform/products/x402 https://docs.cdp.((coinbase.com))/x402/core-concepts/how-it-works https://(github.com)/coinbase/x402/tree/main/python/x402 https://www.x402.org/ecosystem The x402 payment protocol is indeed super simple and stateless. The core idea is adding an `x-payment` field to the HTTP request header, which eventually reflects on-chain. For example, in the sample shown in the image: on the Base network, a small payment in USDC was made for a service. The payment request included the JSON content noted in the image, which contains payment-related fields and the signature result (`signature` value, which requires the wallet's private key to generate). Once it's on-chain, it corresponds to the `transferWithAuthorization` mechanism in the USDC contract shown in the image (this is also an offline signature mechanism). After successfully going on-chain, the payment is complete, and the user receives a response indicating success. As for what the response contains, that depends on what the service provider wants to give you—maybe a token, some paid materials, VIP services, etc. The x402 payment protocol doesn't handle that part. The protocol simply completes this straightforward, stateless, one-time payment. Once the payment is done, it's done. All the extra stuff isn't within the scope of x402's responsibilities. Here are some tests: https://www.x402.org/protected Base Sepolia network https://(proxy402.com)/jP3SOrm8QL Base mainnet—this is a note I uploaded, and you can access it for just 0.000001 USDC. // Note: If any unexpected charges occur during these tests, stop signing immediately. Once you start brainstorming, scams can become very creative. Everyone, please be cautious and evaluate whether it's worth letting your wallet complete the signature or allowing your AI Agent or MCP Client to use your private key to automatically handle some payment interactions. Be careful not to lose too much money. The x402 payment protocol is essentially a practical standard for payment processes led by Coinbase. Other major players can choose to adopt or expand upon this standard. These decisions aren't technical issues but rather a matter of whether they want to follow suit... Finally, I recommend checking out the materials listed above and trying it out yourself. It's easy to get started!