Fulfillment Constraints API reference

The Input object is the complete schema that your function can receive as input.

For a list of fields that the Fulfillment Constraints API's Input object accepts, refer to Input.

The following example shows an input query:

The following example shows the resulting input to the query:

The FunctionResult object is the shape of the function's output.

Output objects can return a value of 0 to n fulfillment constraints. The following function result specifies that DeliverableCartLine 1 and 2 must ship or fulfill from same location, and lines 3 and 4 must ship or fulfill from locations 1 or 2:

Optionally, the deliverableLineIds key can be omitted from the constraint operation to indicate that the fulfillment constraint should be applied to all deliverable lines within the cart.

In scenarios where FunctionResult returns results that can be further combined, Shopify will automatically combine these fulfillment constraints before processing.

In this scenario, the output contains two constraints with the same type MustFulfillFrom and the same location IDs 1 and 2. These two constraints can be combined because DeliverableCartLine 1, 2, 3 and 4 should all fulfill from locations 1 or 2.

In above scenario 1 - 1, if the second constraint has the location IDs 1, 2 and 3, the reducer won't combine the two constraints.

If the same DeliverableCartLine(s) has multiple MustFulfillFrom constraints, the reducer will take the intersection of location IDs.

In this scenario, the output contains two constraints with the same type MustFulfillFromSameLocation. Shopify combines them because DeliverableCartLine 2 must be fulfilled from the same location as DeliverableCartLine 1, 3 and 4.

In this scenario, the output contains two constraints with different types. DeliverableCartLine 2, 3 and 4 must fulfill together and at the same time, DeliverableCartLine 1 and 2 must fulfill from location 1. To meet both constraints, DeliverableCartLine 3 and 4 must fulfill from location 1.

In scenarios where FunctionResult returns constraints that are mutually exclusive, checkout won't return any shipping rates.

In the following example, DeliverableCartLine 1 and DeliverableCartLine 2 can't be fulfilled together because they must fulfill from Location 1 and 2 respectively.