Use for questions about any version of Yii Rest Api, an open-source MVC framework for writing Rest API's in PHP5+
Yii provides a whole set of tools to simplify the task of implementing RESTful Web Service APIs. In particular, Yii supports the following features about RESTful APIs:
Quick prototyping with support for common APIs for Active Record;
Response format negotiation (supporting JSON and XML by default);
Customizable object serialization with support for selectable output fields;
Proper formatting of collection data and validation errors;
Support for HATEOAS;
Efficient routing with proper HTTP verb check;
Built-in support for the OPTIONS and HEAD verbs;
Authentication and authorization;
Data caching and HTTP caching;
Rate limiting;