Having some difficulty trying to get Fiddler to capture a running dotnet api.

[Aaron]

I have a dotnet core project (web api) running on port 5000 locally. I then have 2 clients (postman and a android emulator running flutter) that are running, also locally. I have Fiddler running and it's capturing some traffic (teams, firefox, spotify, etc). But when I make a request in postman or in the flutter app on the android emulator, it is not capturing anything.

What do I need to check/do to make this work?

[Aaron]

I may have posted this in the wrong forum, I'm using Fiddler Everywhere.

[Aaron]

I have gotten a little farther. It seems anything to 127.0.0.1 or localhost doesn't use the system proxy. I changed my server to use my machine IP to listen on and now postman works when requesting from that IP.

I reconfigured my android emulator to force the proxy settings for fiddler but that doesn't seem to work. I have my IP to connect to as my machine IP, but fiddler just shows Tunnel To, my machine IP and port for my app, and the method is connect, but nothing else happens. Any ideas?

[Aaron]

I'm come to the conclusion that there is something wrong with Fiddle Everywhere. I downloaded charles-proxy and it works fine with the android emulator set to use it as a proxy. But if I close that and open Fiddler Everywhere and set it as the proxy in the Android Emulator, connections fail to work, and all I see in Fiddler is a CONNECT but it's not passing the traffic onto the server. None of this is SSL traffic, all HTTP.

[Nick Iliev]

Hello Aaron,

 

Once again, thank you for all the detailed information and feedback provided related to your Fiddler Everywhere issue. As you have discovered and reported in the feedback portal the issue is indeed related to a problem when setting a proxy on an Android emulator/device. The team will investigate and plan the issue and any additional information will be posted in the linked thread.

 

Regards,
Nick Iliev
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[Andrew]

I am having similar issues with "fiddler everywhere" being able to see traffic from my flutter app

IOS Simulator - Version 11.5

Macbook - 2015 running OS Catalina Version 10.15.4

Is there any progress on a fix for this or is there any steps i can take to get it working?

[Nick Iliev]

Hello Everyone,

 

Android recently introduced additional security for mobile applications running on newer API versions. Check these instructions on how to enable the app to use the Fiddler trust certificate.

 

Regards,
Nick Iliev
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[Andrew]

Hi Nick, cheers for the reply! 

I am currently using the IOS Simulator to run my flutter application, is there something similar i can add to the info.plist?

[Nick Iliev]

Hey Andrew,

 

I am not aware of any additional code that needs to be introduced for capturing traffic from iOS applications. Could you try to explicitly trust the Fiddler generated certificate:

On iOS 10 and later, after installing the FiddlerRoot certificate, go to Settings -> General -> About -> Certificate Trust Settings and manually enable full trust for the FiddlerRoot root certificate. Accept the dialog that says that this will allow a third-party to eavesdrop on all your communications.

 

Regards,
Nick Iliev
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