How should I build a custom fulfillment service workflow?

Have your service read fulfillment orders assigned to it, process the work at the warehouse, and report progress and shipments through the documented API operations.

First agree which buildings it serves, when work is ready, and which system manages each inventory location. Map products, carrier services, partial quantities, cartons, and tracking. Decide how cancellations, unships, failures, and late updates will be reconciled.

1. Configure the fulfillment integration on the building or fulfillment rule, then verify assignment on a sample fulfillment order.
2. Read assigned work and store the warehouse’s identifier alongside the Endless fulfillment ID.
3. Move accepted work through the documented fulfillment statuses.
4. Report shipped quantities, cartons, carrier services, and tracking as they occur.
5. Apply inventory updates according to the agreed responsibility for each location.
6. Reconcile open work and inventory periodically.

Check the current fulfillment status before retries or delayed updates. A timeout may follow a successful shipment report. Do not create another shipment, carton, or inventory adjustment without checking what Endless already recorded.

Keep shipment reporting and inventory synchronization independently retryable so a failure in one does not repeat the other. Confirm cancellations in both systems.

Use the API reference for exact transitions and prerequisites. Test a partial shipment and cancellation before processing live work. See assignment and notifications, API connection, and error handling.