A webhook arriving at your application is an event to inspect, not automatic permission to perform business work. Separate receiving the event, verifying its authenticity, saving a durable receipt, and processing its business meaning. Keep a small event identity and status record, so repeated deliveries can be recognized without repeating the same effect. Test duplicate, reordered, and replayed events, including a failure after receipt but before processing finishes. Make the receipt visible to operators and distinguish received from completed. A verified inbox gives recovery a starting point, while the workflow still checks whether the requested action is valid now. Original article explainer. AI-assisted conceptual illustration and neural narration; original synthesized music. Not a human recording or customer result.