Is there any plan for the ability to discard previously used idempotency keys, so that a request with all the same parameters can actually be duplicated? Sometimes a payment will fail because a customer's card is declined (e.g. because of fraud detection or insufficient funds), and after the customer sorts it out, we'd like to try recharging their card, and not just receive the same error message. Our current workaround is to wait 24 hours for the idempotency key to expire, but it would be nice to be able to retry the request sooner without maintaining state on our side to generate a different idempotency key for the same payment.
This is by design. If you want to make "another attempt", you should use a new idempotency key. Think of it as "one attempt/transaction/request" == "one idempotency key".
Yes, exactly! Like you say, the idea is that an idempotency key represents a single request. It's perfectly okay to make a new request that's almost identical to the original in that it shares the same endpoint and all the same parameters, but that should be done using a freshly generated idempotency key.
