[olliej]

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