Fictional processor
An external system with an authored contract
- Payment service Check the existing operation
- Payment service Submit another payment after timeout
- Payment service Submit the same refund operation
Incoming
- Payment service Check the existing operation
A bounded, on-demand read asks the fictional processor about the existing operation. An unanswered lookup leaves the outcome unknown; it does not start another payment.
- Payment service Submit another payment after timeout
Unsafe proposed change: a timeout creates a new logical payment and new operation key immediately, although pay-1001 may already have succeeded. Authored scenario; not an executed test.
- Payment service Submit the same refund operation
The payment service submits refund-op-1001 with identical refund parameters. A retry of that logical refund retains the key inside the fictional contract window.
Outgoing
- Confirmation handler Receive payment confirmation
The fictional processor sends authored event evt-9001 for pay-1001, processor reference processor-pay-7001, EUR 10000 captured. src-processor-confirmation records this prepared evidence.
- Confirmation handler Receive refund confirmation
Authored event evt-9002 confirms refund-1001 for EUR 10000 against pay-1001. src-refund-confirmation does not establish bank posting.