APIs are not code. They are functional interfaces that code interacts with. The decision to have a function called `sqrt` and put it in a module called `math` is not creative, and it is definitely not artistic.
You can’t copyright that - precisely because it is not a significant creative work.
The question is an API a significantly creative work, vs the implementation.
Historically - because the entire modern world depends on it - APIs were not considered copyrightable, largely because the creativity is embodied by the implementation.
You clearly disagree, I am curious if you believe being able to have competing software was detrimental - for example say MS claimed copyright over the XMLHttpRequest API? Or google over search engine query API, etc
"The decision to have a function called `sqrt` and put it in a module called `math` is not creative, and it is definitely not artistic."
Yes, it absolutely is, in the sense that literally any arbitrary sentence or gibberish that I write is creative and copyrightable.
I can copyright: "Blahdy Blady Blady Blah" right now.
API design is as creative as any other part of the code.