[hharnisch]

I was expecting another company copying the core business logic based off the title, but it looks like things related to redirect and auth are very (very) similar.

Nearly every API is going to need solutions for these, and they all look very similar. I'd be surprised if the redirect and auth parts weren't at least in some way inspired by other APIs.

[avip]

It "looks" like they verbatim copy-pasted the documentation (and the api).