fourofour is not as semantic as notFound, or not_found xD ..

idk. this mixes up routing and api building, right? What people currently use most to build their api (mostly afterwards) is: http://docs.guzzlephp.org/en/latest/

btw. here's a nice and new php framework I've just recently found: http://www.cygniteframework.com/2013/07/quickstart.html