I think that's the case already? He's communicating with some unauthorized API that's hosted on a third party.

Apple's argument is that they know that there's no official API so his can't be legal.

Hmm, I doubt that is the case. It’s almost certain they are using TeslaSwift, an open source swift implementation that communicates directly with Tesla’s own private APIs.

It’s quite common for you to instead do such a thing, since the cost of hosting such a service is nothing for you. The APIs are also extremely stable, so it’s not like Tesla is going to pull the rug from under you.

The only benefit of layering your own API on top of Tesla’s would be some sort of data collection.

"I'm accessing API of RealSweetSolutions GMBH as far as I know. It is impossible for me to know their relationship with Apple".

Sure, that's what I thought too, but at the end of the day it is a judgement call from Apple, if they think you're hiding your use of unofficial APIs, I guess they will also deny your updates...

So much power in a company is really scary IMHO.

Oh, I see, then I misunderstood their situation. Thanks for clarifying.

Would there be any way for them to know whether you're doing it, apart from noticing that certain responses your backend seem similar to those from another API?

They could take a guess that myapp.com shouldn’t have control over a Tesla. It’s publicly verifiable that Tesla doesn’t provide official API documentation or access to 3rd-party developers.