Reliable webhook-to-task handoff — local Python demo

Self-initiated Rivetfern demonstration using synthetic events. This is not paid client work or a production deployment.

I built a local Python HTTP receiver that validates a documented HMAC signature and strict JSON shape before recording accepted events in SQLite. A worker leases queued events, retries transient failures within a finite budget, and quarantines permanent failures. The local destination uses event IDs to avoid duplicate tasks.

The reproducible scenario covers a normal event, duplicate delivery, retry, permanent failure, forged signature, and conflicting payload. Three unique events enter the queue; two produce local tasks and one enters the dead-letter state. No email, external webhook, order, or real customer action is sent. I used AI assistance during development, reviewed the code, and ran the tests.

See the [public case study and code bundle](https://www.twine.net/signin The sample uses its own signature contract, not Stripe’s. A real integration would require the provider’s schema and verification rules, HTTPS, access control, monitoring, retention and an idempotent destination.