POST /orders is the programmatic twin of forwarding a purchase-order email: send the order document(s) and Mercura runs the same intake pipeline. Accepted files, size caps, primary-file selection, context, customer resolution, idempotency, and the async JobAck → poll / webhook flow are all identical to POST /tenders — see the Tenders chapter. The only difference is the request type: an order skips LV parsing and runs the order-processing agent (metadata extraction + line matching).