Need ability to update base descriptor in iProcurement for existing items which are not linked to an

We have a requirement wherein we want to populate a base descriptor in iProcurement for existing catalog items which are not linked to agreements. Currently, in order to update base descriptor data we need to put the data as part of the catalog bulk upload (used for agreements). We need ability to pull data from inventory base tables without bulkload. Is there an API that can be used for this?

We need to be able to identify catalog items based on the item_type under iProcurement search results page. We have created a new base descriptor to display the Item Type but no value shows up under this descriptor in iPROC. The base descriptor is referencing table PO_ATTRIBUTE_VALUES and column TEXT_BASE_ATTRIBUTE3 which is not populated. How to populate the data in this table/column so that it shows in iProc under the base descriptor? We need the data in this column to come from MTL_SYSTEM_ITEMS_B table and ITEM_TYPE column.