I've looked at both the Shopping API and the Finding API. I'm trying to ebay Product IDs to use in the Add Item call. My issue is that I can get them from Find Products call in the Shopping API but I can't narrow the results by Category. In the finditemsadvanced call I can see you can narrow down by category but I'm only looking for eBay Catalog products and nothing else. Any suggestions?
You are correct it does but you can not use both QuerKeyword and CategoryID at the same time.
https://developer.ebay.com/Devzone/shopping/docs/CallRef/FindProducts.html Include a Category ID number in your request to restrict your query to a specific category. The request requires a single one of these three elements: QueryKeywords, ProductID, or CategoryID, and can only include one of the three.