It would be great to have the NPC perform an action after a trading is completed.
I'm trying to make it send the traded items to a different location via summoning the exact number of items that are being traded into a hopper, but right now there's no way I can tie that to an actual trade.

Ideally each trade slot would be able to call an action upon trading. If not, then making it so the NPC can have an inventory could solve the issue, especially if the inventory can then be pushed into a hopper by having the NPC stand on it.

For context, we're looking for a way to have the NPCs send items into a storage/processing line.

Thank you for your consideration :)