Use the REST-based Taxonomy API to retrieve category tree information such as category names, category IDs, hierarchy level, parent-child relationships, and whether a category is a leaf category. Since this is a Legacy Trading API guide, note that the REST-based Taxonomy API and Metadata API replace functionality that was previously accessed through the now-decommissioned GetCategories and GetCategoryFeatures calls. Also see Migration guides.
Start by calling getDefaultCategoryTreeId for the target marketplace, and then call getCategoryTree to retrieve the category hierarchy. Use the REST-based Metadata API to retrieve category-level listing policies and supported features. Depending on the information you need, call the appropriate marketplace metadata method, such as getCategoryPolicies, getItemConditionPolicies, getListingTypePolicies, getListingStructurePolicies, or getNegotiatedPricePolicies.
To determine which item specifics are required, recommended, or available for a category, call getItemAspectsForCategory in the Taxonomy API. If your application needs item-specific metadata for all leaf categories in a marketplace, use fetchItemAspects.
In a REST workflow, you may need to combine Taxonomy API data with Metadata API data to build a complete view of a category and the features it supports. For example, Taxonomy API methods can be used to identify a category's place in the hierarchy and whether it is a leaf category, while Metadata API methods return the listing policies and supported features that apply to that category.