richerman: You will understand the x402 protocol in 5 minutes.
The user makes a request to the AI, 'Use my wallet to help me buy a pair of jeans online.' After receiving the request, the AI initiates the purchase, and the store constructs a preliminary transaction that includes the wallet address to be used, the chain to be used, the currency, and the amount. The AI then sends this transaction to the x402 protocol validator to check whether the corresponding wallet on the corresponding chain has sufficient assets, whether the goods are tradable, and whether the user has confirmed authorization. The transaction is then completed.
1. What is the x402 protocol?
First of all, the x402 protocol is a payment protocol centered around 'machines and APIs'. Traditional payment protocols are 'human-centered', to give a relatable example:
You created an AI service that charges 0.01 USDC each time an interface is called. In the traditional way, you would: user registers an account → recharge balance → you manually settle in the background.
In x402 mode: you just need to expose an HTTP interface (supporting x402) —
The user's AI agent will automatically check each time it requests:
'Oh, this request costs 0.01 USDC, pay directly on-chain.' Then it immediately returns the result, without any need for login or recharge. The entire process is almost 'real-time settlement, automatic execution'.
Traditional payment solves the 'transaction between people and websites'; x402 solves the 'transaction between programs'. Figure 1 shows the process comparison.
2. What is the relationship between $ping and the x402 protocol?
To summarize in one metaphor:
$PING is not a 'token generated by x402', but a 'token for transactions completed on x402 for sales/minting'.
To make it shorter:
x402 is a 'payment gateway', and $PING is the 'goods sold through this gateway'.
The generation process of $ping is shown in Figure 2:
Users initiate an HTTP request to an interface that supports the x402 protocol, and the server returns '402 Payment Required', telling you how much you need to pay (the initial minting cost of $PING is approximately 1 USD, and if successful, you can obtain about 5000 $PING), pay and successfully mint.
However, the $ping on-chain transactions have already been fully minted and then traded on-chain. Therefore, there is no issue of unlimited issuance.
So, asset issuance is just one application scenario of the x402 protocol. For AI like Ai16z and Virtual, x402 is the most suitable weapon. And in comparison to $ping, it would be $tst and $pandora, which are specific tests of a brand new protocol.#x402
