How do you get request body data in controller?

[eluser]SpudNik[/eluser]
Hey all..

I am POSTing data to my ci controller using content-type application/json. I know that input->post() will not work. I read somewhere that there is a class that will allow me to get the request body data. Is this documented? I could find anything but input->post Any examples? Basically I just want to get key/value pairs from json being posted to my controller and I'd rather not change the content-type header if possible.

Thanks!