Is inventory management hardcoded?

I’m toying with the idea of writing some code to help with inventory management. I’ve looked around a bit but haven’t found the answer to my title question.

I would like to have an item retrieved from the ground placed directly into a container for that type of item. Gems into gem bags, scrolls into scroll cases, ammo into ammo belts and everything else into bag of holding. If those containers aren’t in inventory, or they are full, just put the item into a standard inventory space.

Thanks for your time and Happy New Year!