Australia Post Shipping & Tracking API (REST, Australia)

The Australia Post Shipping & Tracking API is the REST surface for shipments originating in Australia on the Australia Post and StarTrack networks. It exposes shipment creation, label generation, manifest management, and tracking-event lookup as JSON over HTTPS. Authentication uses an API key passed in the `Authorization` header, paired with an Australia Post account number that scopes the call to a specific contract. The API is distinct from the consumer-facing MyPost Business product and from any logistics-aggregator surface. Australia Post issues commercial credentials through the Developer Centre, and many features (such as international rate calculation, signature-on-delivery options, and StarTrack road-freight services) require explicit production enablement on the underlying account before they appear in the API responses. Operationally, the most common gotchas are rate parity between sandbox and production for international destinations, label-format negotiation (PDF, ZPL) tied to per-account printer configuration, and tracking-event vocabulary that is more granular than most northern-hemisphere carriers — for example, separate events for road-freight handovers and depot transfers. Webhooks for tracking are available through a separate enrollment; signature validation must run against the raw request body, and consumers must tolerate eventual consistency in the carrier's status timeline.