I have a few questions about the x402 payment flow and would appreciate some clarification

[vseae]

Hi team,

I have a few questions about the x402 payment flow and would appreciate some clarification:

1. Does your implementation currently support only the exact payment scheme?

2. How is the charge for a specific request calculated?

   • Is the amount determined fully in advance by the server?
   • Is there any way for the client to inspect the pricing breakdown before the payment is executed?

3. What happens if the client sends more than the required amount by mistake?

   • Will the extra amount be refunded automatically?

I’m asking because clearer guidance on supported payment schemes, pricing logic, and refund handling would make integration much easier.

Thanks.