Order API

Overview

An order API lets systems create, retrieve, update, cancel, and track commercial orders and their items, totals, customers, payments, and fulfillment state. Order state is not identical to payment or fulfillment state. Reconciliation should compare order totals, payments, refunds, inventory reservations, and delivered quantities across systems. It can manage line items, prices, taxes, discounts, addresses, status, and external references. Changes to Order API should be checked against older clients, stored payloads, enum growth, default behavior, and retry assumptions.

Integrations should use stable order and item identifiers, idempotency, immutable financial snapshots where appropriate, and validated state transitions. An order API connects storefronts, marketplaces, inventory, payments, shipping, support, and accounting around a shared commercial record. Concurrent updates and duplicate creation require explicit consistency and version rules. An order can be authorized but unpaid, paid but unfulfilled, partially shipped, refunded, or canceled with retained records. Observability for Order API should record operation, version, principal, request ID, latency, retry count, error code, and final state without exposing secrets.

Testing Order API should cover malformed input, denied access, rate limits, timeouts, duplicates, asynchronous completion, and version changes. The Order API owner should publish stable error semantics and guidance on whether correction, retry, status lookup, or escalation is appropriate.

Data handled by Order API should use documented types, units, timestamp rules, nullable fields, and enum behavior to prevent silent interpretation errors.

The Order API contract should define identifiers, validation, authorization, status semantics, errors, limits, and version behavior at the same boundary.

For Order API, the application should preserve a correlation path from request construction through response, asynchronous completion, and final business state.