#idempotency

Prevent duplicate booking and payment caused by agent loops, retries and tool invocation using idempotency, side-effect guards and UNKNOWN-aware recovery.

Identify duplicate travel bookings created after timeout/retry, preserve the correct reservation and apply safe compensation.

Design idempotency boundaries and duplicate-booking safeguards across travel booking, payment, cancellation and refund operations.

Model payment and supplier booking as a distributed transaction using authorization, capture, compensation, UNKNOWN outcomes and reconciliation.

Handle duplicate, delayed and out-of-order webhook events safely with deduplication, replay rules and idempotent state transitions.

Design travel-booking state around create, confirm, modify, cancel, fail and reconcile events with explicit ordering and idempotency.

Handle unknown booking state after create timeouts using idempotency, lookup, payment evidence and reconciliation instead of blind retries.