How to monitor network calls made from iOS Simulator

Recently i found a git repo that makes it easy.

You can try it.

This is an app's screenshot:

Best regards.

Personally, I use Charles for that kind of stuff.
When enabled, it will monitor every network request, displaying extended request details, including support for SSL and various request/reponse format, like JSON, etc...

You can also configure it to sniff only requests to specific servers, not the whole traffic.

It's commercial software, but there is a trial, and IMHO it's definitively a great tool.

A man-in-the-middle proxy, like suggested by other answers, is a good solution if you only want to see HTTP/HTTPS traffic. Burp Suite is pretty good. It may be a pain to configure though. I'm not sure how you would convince the simulator to talk to it. You might have to set the proxy on your local Mac to your instance of a proxy server in order for it to intercept, since the simulator will make use of your local Mac's environment.

The best solution for packet sniffing (though it only works for actual iOS devices, not the simulator) I've found is to use rvictl. This blog post has a nice writeup. Basically you do:

rvictl -s <iphone-uid-from-xcode-organizer>

Then you sniff the interface it creates with with Wireshark (or your favorite tool), and when you're done shut down the interface with:

rvictl -x <iphone-uid-from-xcode-organizer>

This is nice because if you want to packet sniff the simulator, you're having to wade through traffic to your local Mac as well, but rvictl creates a virtual interface that just shows you the traffic from the iOS device you've plugged into your USB port.