How does the system prevent duplicate orders on double-click (idempotency)?

Order creation is idempotent: a duplicate submission or a double-click on "pay" results in only one order and one charge, not two. The checkout is built so that repeating the same submit doesn't create a second order — a common real-world glitch (impatient clicking, a retried request) that naive systems turn into double orders and double charges. Idempotency here protects both the…

Order creation is idempotent: a duplicate submission or a double-click on "pay" results in only one order and one charge, not two. The checkout is built so that repeating the same submit doesn't create a second order — a common real-world glitch (impatient clicking, a retried request) that naive systems turn into double orders and double charges. Idempotency here protects both the customer (charged once) and the operator (one clean order).