I'm quite disappointed in the HAL representation, it lacks standard compliant link relations. OPTIONS is not supported. PATCH with application/merge-patch+json is not supported. Range on items is not supported. JSON home document is not supported. Deprecation is either not supported or undocumented. HTTP authentication schemes are either not supported or undocumented. It looks like the authors of this software don't know what they're doing; I could build much richer HAL documents than them. Try with httpie to see what I mean:

http -v https://demo.api-platform.com/books/526eea89-f98c-4dfc-80bb-... Accept:application/hal+json