I think it's great that we're talking about standardising how we build RESTful JSON APIS. However I don't think this has got it quite right yet. What's the reason for the top level rel? It seems like it's just there to stop the urls from being repeated and to save space, but isn't that what gzip is for? Why complicate the data format and require all that extra logic and gzip would remove most of the redundancy before…
It also makes it possible to cache things locally indexed on their IDs, and to form URLs that make requests for just the precise documents that aren't available locally. In order to achieve this, it's necessary to have both (1) IDs, and (2) a way to convert a list of IDs into a single request for all of the documents at once.
> Also the name is a bit of an annoying land grab
HAL is "The Hypertext Application Language". In general, people tend to be using generic names for these things, so I chose an available, generic name.
> Lastly, it really seems based on a rails active record style data store, it's assuming ids are the most important thing and that links are all relations that point to other objects within the system
I reviewed a large number of server-side solutions (Firebase, Parse, CouchDB, Django, Rails) and they all had the concept of an ID for the document. As I said above, this ID is useful to keep track of which documents have already been cached locally, and how to formulate a URL that makes a request for just the missing URLs. I don't consider this solution to be particularly tied to ActiveRecord.
Less importantly, it is also more convenient to cache documents on the server using their IDs (or slugs, or whatever the storage wants to use), and allow a top-level configuration to define how to generate URLs. This allows server-side solutions to serialize and cache documents without having to be plugged into the router architecture, but enforces a URL-centric view once the HTTP response is built.