* versioned API (either via URI or the Accept-Header)
* All function/method calls have to be fully-nonblocking. If an expensive call has to be made to a backend system, the client needs to be provided with a status URI which can be checked for the current status
* Input validation must be performed for all data(validation of data happens twice: in the API and the client)
* Meaningful error message will be presented to the client
* All API functions are to be documentedusing an accepted documentation standard (doxygen (preferred), phpDocumentor or Sami)
* The API will be based on existing, proved and tested open source modules and components, coming either from a framework are as stand alone implementations,
* Base for [http://en.wikipedia.org/wiki/Responsive_web_design responsive] resp. [http://www.abookapart.com/products/mobile-first Mobile First] Web-Applications/-Design
Known issues/drawbacks:
* Validation of data happens twice: in the API and the client (javascript)
=== Yii related API modules ===