The Order API is used to manage fulfillment orders. Use it to create new orders, or to update, cancel or to get information about already created orders.

Use of externalIds and the “canSplit” option
External ids must be unique in our system, so, when splitting orders across two warehouses, we follow the convention of adding “.1” to the first order’s externalId and “.2” to the split order. You will need to use this when trying to GET an order by its externalId, or to cross reference the externalId in an order.completed webhook JSON body with the original externalId on your end.