A Hypermedia API Reading List

Originally, this post was titled "A RESTful Reading List," but please note that REST is over. Hypermedia API is the new nomenclature.


I'll be updating this post as I get new resources, so check back!

If you want to go from 'nothing to everything,' you can do it by reading just a few books, actually. I'm going to make all of these links affiliate. I purchase a lot of books myself, maybe suggesting things to you can help defray the cost of my massive backlog. All are easily searchable on Amazon if you're not comfortable with that.
Start off with Restful Web Services by Leonard Richardson and Sam Ruby. This book is fantastic from getting you from zero knowledge to "I know how Rails does REST by default," which is how most people do REST. But as you know, that's flawed. However, understanding this stuff is crucial, not only for when you interact with REST services, but also for understanding how Hypermedia APIs work differently. This baseline of knowledge is really important.
It also comes in cookbook form. You really only need one or the other; pick whichever format you like.
Next up, read REST in Practice: Hypermedia and Systems Architecture. This book serves as a great bridge to understanding Hypermedia APIs from the RESTful world. Chapters one through four read like Richardson & Ruby; yet they start slipping in the better hypermedia terminology. Chapter five really starts to dig into how Hypermedia APIs work, and is a great introduction. Chapter six covers scaling, chapter seven is an introduction to using ATOM for more than an RSS replacement, nine is about security, and eleven is a great comparison of how Hypermedia and WS-* APIs differ. All in all, a great intermediate book.
To really start to truly think in Hypermedia, though, you must read Building Hypermedia APIs with HTML5 and Node. Don't let the title fool you, as Mike says in the introduction:

[HTML5, Node.js, and CouchDB] are used as tools illustrating points about hypermedia design and implementation.

This is not a Node.js book. I find Node slightly distasteful, but all the examples were easy to follow, even without more than a cursory working knowledge.
Anyway, the book: Mike says something else that's really important in the intro:

While the subject of the REST architectural style comes up occasionally, this book does not explore the topic at all. It is true that REST identifies hypermedia as an important aspect of the style, but this is not the case for the inverse. Increasing attention to hypermedia designs can improve the quality and functionality of many styles of distributed network architecture including REST.

And, in the afterward:

However, the aim of this book was not to create a definitive work on designing hypermedia APIs. Instead, it was to identify helpful concepts, suggest useful methodologies, and provide pertinent examples that encourage architects, designers, and developers to see the value and utility of hypermedia in their own implementations.

I think these two statements, taken together, describe the book perfectly. The title is "Building Hypermedia APIs," not "Designing." So why recommend it on an API design list? Because understanding media types, and specifically hypermedia-enabled media types, is the key to understanding Hypermedia APIs. Hence the name.
Mike is a great guy who's personally helped me learn much of the things that I know about REST, and I'm very thankful to him for that. I can't recommend this book highly enough.
However, that may leave you wondering: Where's the definitive work on how to actually build and design a Hypermedia API? Did I mention, totally unrelated of course, that I'm writing a book? ;)
Yes, it still has REST in the title. Think about that for a while, I'm sure you can see towards my plans. I'm planning on a beta release as soon as I'm recovered from some surgery this week, but I'm not sure how long that will take, exactly. So keep your eyes peeled.

Books I won't recommend

REST API Design Rulebook , while I haven't actually read it, seems quite terrible. Let me copy an Amazon review:

The first chapters give a good feel for the vocabulary, and some good techniques for implementing REST. A lot of the 'rules', especially those related to basic CRUD operations, are clean and simple with useful examples.
Unfortunately, the later chapters get more and more focused on specifying something called 'WRML', which is a concept/language newly introduced in this book as far as I can tell.
Personally I would recommend ignoring the sections dealing with WRML (or keep them in mind as a detailed example of one possible way of handling some of the REST issues).
As to WRML itself: yuck. It appears to be an attempt to drag in some of the unnecessary complexity of SOAP with little added benefit. Not recommended.

Looking up information about WRML, I can agree, 100%. Ugh. So nasty. So this gets a big fat downvote from me.