The deals can only be signed by countries, but the trade deal treaties have local legal weight or are implemented them using local laws which can then be used i

The deals can only be signed by countries, but the trade deal treaties have local legal weight or are implemented them using local laws which can then be used in any legal dispute. That's literally the point of trade deals: the purpose is to reduce trade barriers for companies. In broad terms that is a good thing, but there are definitely issues in some cases.