Under Review
Last Updated: 17 Jun 2018 05:00 by Sameera
Created on: 30 May 2018 05:47
Type: Feature Request
Support .NET Core / WCF projects by registering as a proxy for WinHTTP
Related to forum thread: https://www.telerik.com/forums/fiddler-no-longer-capturing-web-service-requests-in-net

We found that .NET Core projects use WinHTTP instead of WinINET. As Fiddler registers itself only as a proxy for WinINET, traffic from these projects do not show up in Fiddler. While a manual workaround exits, it would be good if there was at least an option to register Fiddler as a proxy for WinHTTP as well.

On a side note: We've seen that even node.js traffic does not show in Fiddler as well. We've not researched the cause as it wasn't critical to us at that time. But, it could also be due to the same reasons.
Posted on: 17 Jun 2018 05:00
So, the information I can give you Eric, is that as per the thread, a .NET core app's traffic doesn't show in Fiddler unless I run  unless I run
netsh winhttp set proxy

And once I do
netsh winhttp reset proxy

the traffic stops showing up again.
Posted on: 05 Jun 2018 05:00
I would be very surprised to find that .NET Core is really based on WinHTTP, as the .NET team has their own HTTP implementation. You'll need to find out where it gets its proxy settings if it's not using the system settings (what you're calling "WinINET proxy" above).

With regard to node, yes, many node HTTP libraries don't offer explicit control of the proxy at all, and I'm not aware of any that automatically adopt the system's proxy settings. You'll need to explicitly configure your node code to proxy through Fiddler.