Blockchains are fast and and cheap now! Modern blockchains like Base, Solana, Sui (and many more) typically have block times <2 seconds, and a stablecoin transfer can cost as little as $0.0005 independent of the $ amount being transfered
its not that 402 isn't used, its that there is no standard response, which makes it hard for AI agents to pay for access.
x402 provides a standard response format clients can programmatically use to create a payment, either using crypto assets like stablecoins, or in future, fiat methods.
>Given that this runs atop Payment Required, doesn’t this mean that each API request would involve an extra one or two data transfers?
Yes, assuming its the first time you've interacted with an API endpoint and don't have cached payment requirements.
>Is there a reason why you wouldn’t pay ahead of time? I just understand why you couldn’t buy a few dozen/hundred/thousand dollars worth of credits, and wait until it runs low.
This would require manually integrating each vendor, which is totally valid if your agent performs a lot of a single type of task, but we suspect over time there will be huge value in agents being able to dynamically select tools / apis they want to use to accomplish their tasks, and dynamically pay for what they use
This depends on the implementation on the underlying network, but basically the spending signs an authorization for transfer, and the merchant either settles that onchain themselves or delegates to what is called a facilitator that settles on their behalf. On EVM chains for the exact payment scheme this leverages EIP-3009 signatures
x402 as a protocol has no fees, but the underlying network transactions are conducted on my have costs. Merchants can choose the underlying network transactions are conducted on that best fit their usecase. x402 also has the concept of a facilitator, which exists to abstract away the underlying payment networks. Many facilitators (including Coinbase's) subsidize the gas used for transactions.
(x402 author here) Thats actually exactly what the intention with x402 is. Merchants express to the buyer multiple ways that they accept payment and the buyer chooses the one they prefer.
As of right now stablecoins on various crypto rails are the major form (largely because they're the easiest to start with from a development standpoint), but as Cloudflare indicated in their blogpost, they're proposing a scheme that uses deferred payment via credit card or ACH https://blog.cloudflare.com/x402/.
we will happy accept PRs the add support for any chains that can perform the payment flows in a safe, non-custodial way for the client, resource server and faciliator. Currently x402 works with any EVM chain, and we're working with several chains on integrating.
People never discuss company size along with this question.
If you're at a giant company, the answer is likely no, there's enough politicing and paperwork where the highest impact thing to be done by a manager is likely not coding.
If you're at a startup / smaller more nimble org in a big company, the answer is likely yes, if you've gotten to the point where you're a manager, in theory you're a very good engineer and you should spend your time coding, but on things that aren't on critical path. Bug backlog, experimental things with no hard deadlines, proof of concepts, all of these are valuable things. Leading from the front is also just generally good with smaller groups.
Also under discussed by people having these debates (typically managers), is not acknowledging how bad most managers are at coding, especially if their job hasn't required them to code in a while. I see all the time that managers look for any excuse not to code, because it would reveal to their team that they're at best an L4 level coder after being in management for 5-10 years.