Yii2 has a great and new REST API!
I think the best basic REST example (tutorial) at the moment is this one:
Blog: http://budiirawan.com/setup-restful-api-yii2/
The code is on github:
Official Yii2 Guide on RESTful WebServices:
http://www.yiiframework.com/doc-2.0/guide-rest-quick-start.html