How API Idempotency Prevents Double Charges

In this episode of The API Podcast, Lucas and Luna explore idempotency keys — the unsung design pattern that stops payment APIs from charging a customer twice when a network failure causes a retry. They trace how Stripe made idempotency a standard expectation, explain why a simple unique key in the request header is surprisingly hard to implement correctly at scale, and unpack real-world edge cases like expired keys and concurrent requests. The hosts also discuss how idempotency applies beyond payments — to order fulfillment, email sending, and any system where duplicate operations are dangerous. By the end, you'll understand why an idempotent API is a trustworthy one, and why you should always ask 'is this endpoint idempotent?' before building on top of it. #APIIdempotency #StripeAPI #PaymentAPIs #IdempotencyKeys #APIDesign #RetryLogic #DistributedSystems #WebAPIs #RESTAPI #GraphQL #BackendEngineering #TechPodcast #FexingoBusiness #BusinessPodcast #APISecurity #ReliabilityEngineering #PostgreSQL #Redis Keep every episode free: buymeacoffee.com/fexingo