I'm really not sure...
EDIT - they are APIs with the neccesary metadata to be used as GPT plugins.
I was confused by the fact they aren't listed in GPT when you're in plugin mode - but that's just the officially vetted list.
(Before that I was confused by the interchangable use of "plugin" and "api" and the the use of "AI" when OP specifically seems to mean "ChatGPT"...)
I'm really not sure...
EDIT - they are APIs with the neccesary metadata to be used as GPT plugins.
I was confused by the fact they aren't listed in GPT when you're in plugin mode - but that's just the officially vetted list.
(Before that I was confused by the interchangable use of "plugin" and "api" and the the use of "AI" when OP specifically seems to mean "ChatGPT"...)