GuideHTTP
Idempotency keys for payment endpoints in .NET
How to make a charge endpoint safe to retry: key scope, hashing the raw body, the 409 on a mismatched payload, and the race a unique index has to close.
Topic
idempotency
3articles · all topics
Guide
Out-of-order webhooks: what the handler must do
Payment webhooks do not arrive in causal order. How to apply them with a state machine and an event id, instead of trusting which HTTP request landed first.
Guide
Retry and backoff for payment APIs in .NET
Which payment HTTP failures are safe to retry, why a timeout is not one of them, and how backoff without an idempotency key charges the customer twice.