Product quantity types

Each product in the catalog has attributes that indicate how quantities of that product are sold. For example, some products are sold and priced per unit, while others are sold and priced by weight. There are also variable weight products that can be purchased as a unit, but are priced by their weight.

For most products, the cost_unit attribute value indicates whether the product is sold per unit or by weight. Variable weight products that can be purchased per unit are identified by also having a par_weight value defined. For more information, see the Catalog documentation.

The following table summarizes the different product quantity types:

Quantity type	cost_unit	Description
Per unit	each	Items of a fixed size and price per unit. Example: 3 cans of soup
By weight	lb or kg	Loose items purchased and priced by weight. Example: 1 lb of green peppers
Variable weight	lb or kg	Items purchased as a unit, but priced by weight. Relies on the par_weight value defined in the catalog. Examples: 1 package of ground meat or 5 bananas

Specifying product quantity for an order

When you create an order using the Fulfillment API, you specify the product quantity to be purchased by using the count and weight parameters. Although the request accepts both of these parameters for any item, the product's quantity type determines which parameter is required, and how these values are handled by the system.

• Per unit. When specifying a product that is sold per unit, the count value (required) indicates the quantity of the product being purchased. If you provide a weight value, it is added to the order’s special instructions.
• By weight. When specifying a product that is sold by weight, the weight value (required) indicates the quantity of the product being purchased. If you provide a count value, it is added to the order’s special instructions.
• Variable weight. When specifying a variable weight product, you must provide either the count or weight. Regardless of which value is provided, the count represents the quantity being purchased, and the weight is added to the order’s special instructions. If count is not provided in the request, the system calculates the value using the product's par_weight value.