Maybe I'm wildly misunderstanding something, not helped by the fact that I work very little with Web technologies, but...

So, in a RESTful system, you should be able to enter the system through a single URL and, from that point on, all navigation and actions taken within the system should be entirely provided through self-describing hypermedia: through links and forms in HTML, for example. Beyond the entry point, in a proper RESTful system, the API client shouldn’t need any additional information about your API.

This is the source of the incredible flexibility of RESTful systems: since all responses are self describing and encode all the currently available actions available there is no need to worry about, for example, versioning your API! In fact, you don’t even need to document it!

If things change, the hypermedia responses change, and that’s it.

It’s an incredibly flexible and innovative concept for building distributed systems.

Does that mean only humans can interact with a REST system? But then it doesn't really deserve the qualifier of "application programming interface".