Toilet venting for Reno

Hey All. Working on a reno in my basement. Had the basement dug down during the summer and the rough in for the new bathroom installed. There is a venting pipe beside the toilet that is currently capped. I'm unsure if this needs to be connected to something (main stack) or extended and vented to the outside? The contractor said it "just sits in the wall" but after reading about venting this doesn't sound correct. Any help would be much appreciated. Thanks

Waste pipes go down, and vent pipes go up through the roof.
Has your contractor "pulled" a permit for this job yet? And where has he posted his permit?
Have you checked to see if you have enough clearance around your plumbing fixtures?
A toilet of lav needs a 30" space.

Here is a typical drawing of two bathrooms stacked.
Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County