Payment webhook that credits the account
A customer pays, and someone has to spot the email, find the account and add the balance, or the customer waits. The processor calls a webhook instead: the signature is checked, the account is credited and any tier or bonus applied, with nobody reading an email. Each event ID is stored before it is processed, so a repeated delivery is not credited a second time, every payment is logged with its raw payload, and a call that keeps failing raises an alert.