JSON results object

I'm attempting to hit a web service to get some JSON data.  I can successfully get the data, and convert it to the term, but can't seem to figure out how to actually get to the values inside.

What is the best/easiest way to get to the usable data once you have the json(X) term?  For example, my data looks like:

json([size=1, limit=25, isLastPage= @(true), values=[json([... = ...|...])], start=0, filter= @(null)])

Where do i go from here?

I've tried converting it to key pairs, associated lists, asserting it into the database and can't seem to figure out how to get to the meaty goodness inside.

Thanks for helping a prolog newbie that can't seem to get his google-fu on today.