Create and track RMAs in an OMS via the Extensiv Order Manager API

Verified steps

1. Authenticate with the Extensiv (formerly 3PL Central) REST API by exchanging your Client ID and Client Secret (Base64-encoded as ClientID:ClientSecret) for an OAuth 2.0 access token; the token is valid for approximately one hour so refresh programmatically every 50–55 minutes.
2. Create an RMA record by POSTing to the returns/create endpoint with the original order reference, line items being returned, quantities, and return reason codes; capture the returned RMA ID.
3. Share the RMA ID with the customer or your returns portal so inbound shipments can be matched on arrival at the warehouse.
4. When the 3PL receives the return, Extensiv updates the RMA status; poll the GET /returns/{rmaId} endpoint or subscribe to the inbound webhook event to detect when goods arrive.
5. Once the RMA is marked received, inspect the condition codes and trigger disposition logic — restock, quarantine for inspection, or initiate a refund — based on the returned item's condition field.
6. Reconcile inventory by verifying that Extensiv has incremented or quarantined stock for the returned SKUs before issuing the customer refund to avoid overselling.