The Catalog System can be thought of as the Heart of Commerce Server.  Products and categories can be defined in a hierarchical manner within a Catalog. To get all categories exist within a Catalog and products associated with a category can be retrieved using Commerce Server API.

Below is a small example which shows how to get list of all the categories of a Catalog.

Example 1:

//Get the instance of the CatalogContext using ServiceAgent
CatalogServiceAgent catalogServiceAgent;
catalogServiceAgent  = new CatalogServiceAgent("

http://localhost/CatalogWebService/CatalogWebService.asmx");
CatalogContext catalogContext = CatalogContext.Create(catalogServiceAgent);
//Get the ProductCatalog by its Name
ProductCatalog catalog = catalogContext.GetCatalog("Mindfire");
//Get the root category of the ProductCatalog
Category category = catalog.GetRootCategory();

//Get all the categories of the Catalog
CategoryCollection categoryCollection = category.ChildCategories;

 Below example shows how to get the Product associated with a particular Category.

Example 2:

//Get the Cataegory of a Catalog by its name
Category myCategory = catalog.GetCategory("CategoryMindfire");
//Get all the Products belongs to that Category
ProductCollection productCollection = myCategory.ChildProducts;