Key Concepts

Before starting development, you should understand a few central concepts in the data model:


A product is any article that can be sold on It is defined by its European Article Numbering code (EAN), and enriched with descriptions, pictures, and other content.

If the product you wish to sell is not yet available on, you can use the Product Content API to add it. You can also use this API to update product information.

We also provide a means to manage product content through FTPS, although the API is the preferred way to add content.


If a product is offered on the website by a retailer or by itself, this results in an offer. An offer is defined by the combination of product (EAN), retailerID, condition category (new/secondhand) and condition name (for example new, as new). Additionally, an offer must always contain a price and delivery promise.

For example, if two retailers offer the same product for a different price on, this results in two different offers. Also, one retailer can have two offers on the website for the same product: one with condition new and one with condition used.

Orders and order items

When a customer purchases one or more items on, an order is created. The order contains of one or more order items. Each order item contains an EAN, offer reference, quantity, price, customer reference, and other relevant fields.

Later process flows all refer to the relevant orders and order items.

Other concepts and flows

All other process flows are related to one of the previous concepts. A shipment is created when one or more order items are sent to the customer, a return is created when a customer wants to return an order item and a cancellation is used to cancel an order or order item. determines its commissions based on the products.

The full process flow of selling on is described here.