An Attempt to Unify the REST APIs
Best Uses: Novice, Intermediate, Student
Describe Yourself: Developer
For those software and web developers that want to enter to the REST API development, 'REST API Design Rulebook' is a good starting point since it explains through five sets of rules the underlying knowledge of a REST API, their structures, methods, documentation and suggested exposure to client applications and other APIs. On my opinion, and keeping proportions, this book, as a design pattern does, gives to developers the common vocabulary to discuss, specify, design, develop and test RESTful APIs.
The book's chapters are easy, quick reading, except chapter 5 'Representation Design' which is the one that requires more intellectual effort because it explains how to structure well-formed formats for message body (i.e. JSON), hypermedia (i.e. links), media schemas and API errors. Be careful with this chapter since it introduces a new Internet format not yet approved (the WRML), but on author's opinion this new format will become the client–server more verbose with respect to the format of a returned document (i.e. resource).
However, experienced REST developers may already know and have implemented many of the rules defined in the book, and instead be more interested in how to design the back-end service layers that conform to a RESTful API avoiding RPC or RMI practices, if possible. Such inner workings are not covered, but I think they could benefit from this book by performing a 'REST API compliant test' by taking this rulebook as a checklist.
By taking that implicit checklist approach, this book also has the side effect of providing several criteria to evaluate if a software framework that claims to help to the development of REST APIs indeed offers a full set of features that compliant with REST behavior, much more than routing HTTP requests and isolating from user interface artifacts.
Finally, in chapter 7 'Final Thoughts' the author depicts the need to unify a methodology to design a REST API that decreases disparities between APIs and improves team communication. Author depicts his solution known as the WRLM, akin to, say UML and RUP. On my opinion, a more detailed example included in this chapter would have been useful to show us the WRML's full potential rather than visiting the official web page.
In conclusion, 'REST API Design Rulebook' is a good starting point to understand how a REST API is composed, to acquire the proper vocabulary and to apply a more planned API design process. As a side effect, this rulebook helps to evaluate the RESTfulness of an existing API or developer framework.
Note: This review is in exchange for the O'Reilly Bloggers Review Program (http://oreilly.com/bloggers).