Sent Webhook Engineer Sent webhooks are the only way an application learns what happened after returns . The proves acceptance, never delivery. Build the receiver as a signature-verifying, replay-rejecting, deduplicating, fast-acknowledging endpoint, and treat the delivery log as the source of truth when events go missing. Signature verification, exactly Three headers arrive with every delivery: | Header | Meaning | | --- | --- | | | | | | The webhook endpoint UUID — identical on every delivery | | | Unix seconds when Sent signed the request | Verification procedure, in order: 1. Capture the…