Build a schedule-change detection and passenger notification pipeline using Duffel airline-initiated change webhooks

Steps

1. Register a webhook endpoint in the Duffel Dashboard or via POST /air/webhooks; subscribe to the order.airline_initiated_change_detected event type.
2. On receipt, validate the webhook signature using the shared secret Duffel provides, then parse the payload to extract the order_id and the change details (new departure times, flight numbers, routing changes).
3. Fetch the full airline-initiated change details via GET /air/airline_initiated_changes/{id} to retrieve the accepted and changed slices with original vs new times.
4. Classify the change: minor (under-threshold time shift), significant (departure shifted by more than 60 minutes or routing change), or cancellation; apply your business rules for auto-accept vs require passenger decision.
5. Notify the affected passenger with the original and new itinerary details; offer accept, reshop, or refund options based on the severity classification.
6. Respond to the change via PATCH /air/airline_initiated_changes/{id} with action: accepted or action: rejected to close the AIC loop in Duffel's records.