> What makes it hard is understanding the domain, the documentation, the tools and other bits around it. But the point is that, if you can't use the API withou

> What makes it hard is understanding the domain, the documentation, the tools and other bits around it. But the point is that, if you can't use the API without understanding the domain, then the API isn't easy to use. Saying that knowledge isn't _specifically_ the API (just required to use it) isn't reasonable. It would be one thing to say "this specific implementation of OAuth2 isn't hard to use" because, for a specific implementation, you'd only compare it against "the knowledge you need that's different from other implementations". But to use OAuth2 in general, you need all the "other" knowledge. Which translates to "OAuth2 is a hard/complicated API to use".