We have extended endpoint Product insertion to support additional attributes of a product:
brandCode– product brand (manufacturer),
supplierGuid– product supplier,
categoryGuids– array of categories the product should be assigned to,
flags– array of product flags (“New”, “Action”,…) to be assigned to the product, optionally also with the date range to be used.
For detailed description, see documentation, rightmost pane, section “Request” » “Attributes”.