Payment Retry & Idempotency

Use Case / Feature Type: Payment Retry & Idempotency

Context: Users attempt payments that may fail due to network issues, timeouts, or third-party processor errors. The system must allow retries without duplicating charges.

Acceptance Criteria:

• Given a payment attempt has failed due to a transient error (e.g., network or service outage)
• When the user retries the payment using the same payment details
• Then the system processes the payment once, ensuring no duplicate charges and maintaining idempotency

Edge Cases:

• Retry attempts after a partial success (e.g., authorization succeeded but capture failed)
• Duplicate payment tokens or transaction identifiers
• Concurrent retries from multiple devices or sessions
• Network latency causing delayed confirmations

Non-Functional Hooks: Payment retries should complete within 5 seconds; idempotency keys must expire after a configurable window; retry logs must be recorded for auditing; ensure PCI compliance.

Related Stories: Payment Processing, Error Handling.