• Updated 22-Mar-2016 Added VS Code
  • Updated 07-Oct-2016 Added NPM / Node JS
  • Updated 16-Aug-2017 Highlight VS Code is no longer needed

Working in an “Enterprise” type environment means lots of fun obstacles getting in the way of your day to day work – the corporate proxy is one of my challenges.

Since giving up on CNTLM Proxy due to instability and account lockouts, I haven’t been able to connect to nuget.org from the package manager, view the Visual Studio Extension Gallery or even get any extension/product updates from Visual Studio.

This is a quick post with the changes I needed to get Visual Studio 2013 Update 4 (works on 2015/17 too), VS Code 0.10.15, NuGet 2.8 and Web Platform (Web PI) 5 to see past the corporate Squid proxy.


Configuring NuGet based on this Stack Overflow answer by arcain.

Running nuget.exe with the following switches will allow NuGet to use and authenticate with the proxy:

nuget.exe config -set http_proxy=http://proxy-server:3128
nuget.exe config -set http_proxy.user=DOMAIN\Dave
nuget.exe config -set http_proxy.password=MyPassword

It will put the values into your nuget.config file (with the password encrypted)

        <add key="http_proxy" value="http://proxy-server:3128" />
        <add key="http_proxy.user" value="DOMAIN\Dave" />
        <add key="http_proxy.password" value="base64encodedHopefullyEncryptedPassword" />

Once Visual Studio is restarted, it should be able to see through the proxy.

As per the comments on the answer some people might have success without the password – sadly, not in my case. Also, remember if you have to change your password (as I have to every month or so) you will need to re-enter your password.

Visual Studio Code

NOTE: VS Code 1.15 has built in proxy support. I’m leaving the below in place as it forms the basis for NPM, and might still be useful in some circumstances.

Visual Studio Code is a tricky one to setup because it isn’t .NET, it’s all JavaScript based. Most of my information came from the GitHub issue.

  • Determine your proxy server and port. When you have a complicated proxy, this is a pain and it took me a while as I use an automatic configuration script. If it is a standard server/port combo, you’re on an easier path.
  • I usually configure IE with a script from a URL like this one: http://proxy-server/script.dat. This is a plain JS script which, after a bit of looking at, I discovered pointed to proxy-cluster.fqdn.local:8881.
  • Now I have a server and port I need my authentication details.
  • Let’s assume my NTLM login is DOMAIN\User Name and my password is [email protected]!
  • The format for the credentials needs to be DOMAIN\User Name:[email protected]!, but you need to URL Encode the user name and password.
  • A simple online URL encoded can translate your username and password to: DOMAIN%5CUser%20Name and P%40ssword!.
  • Piece all this info into a single string like so: http://DOMAIN%5CUser%20Name:P%[email protected]:8881
  • Then add this into your User Settings in File, Preferences against the "http.proxy" value:
// Place your settings in this file to overwrite the default settings
    "http.proxy": "http://DOMAIN%5CUser%20Name:P%[email protected]:8881"

There are a lot of ways to mess this up, I almost gave up on VS Code after weeks of messing about, the removal of C# from base product made it “make or break time”. If you are struggling I suggest you re-read the GitHub issue. The main tip I found useful was to pop-open the Developer Tools in VS Code (under Help) and in the JavaScript Console run: require('url').parse('YOUR PROXY URL') and check the output.

Big thanks to João Moreno for all his comments on the GitHub issue.

NPM (Node JS)

To use NPM there are 2 options:

  1. NPM Setting Variable
  2. Command Line Switch

Both require the NTLM authentication URI from the Visual Studio Code section above, so read that if you need to.

NPM Config

You can just run the following from the command line:

npm config set proxy http://DOMAIN%5CUser%20Name:P%[email protected]:8881

The disadvantage of this is that it is always visible on your system, so you might want to remove it after installing packages:

npm config rm proxy

Command Line Switch

When calling npm you can pass the NTLM authentication URI as a switch like so:

npm install --proxy http://DOMAIN%5CUser%20Name:P%[email protected]:8881 jslint

This requires you to know your proxy URI in advance, but if you are storing it in VS Code, you can copy and paste from there.

I’m currently wrapping all NPM operations in Powershell scripts that automate checking of packages on disk, then prompting for authentication details if needed and building the URI on the fly.

Visual Studio

Setting up Visual Studio based on this blog post by Raffael Herrmann.

  • Open the devenv.exe.config file. I find it by right clicking the Visual Studio shortcut, selecting Properties and then “Open File Location”. If you have UAC enabled you will need to open it in a program running as Administrator.
  • Scroll to the end of the file and find the system.net section:
<!-- More -->
        <ipv6 enabled="true"/>
<!-- More -->
  • Add the following below </settings>:
<defaultProxy useDefaultCredentials="true" enabled="true">
    <proxy bypassonlocal="true" proxyaddress="http://proxy-server:3128" />
  • The final version will look something like this:
        <ipv6 enabled="true"/>
    <defaultProxy useDefaultCredentials="true" enabled="true">
        <proxy bypassonlocal="true" proxyaddress="http://proxy-server:3128" />

Web Platform Installer

This was the same set of changes needed for Visual Studio, except with the WebPlatformInstaller.exe.config file, which I again obtained from the shortcut properties using “Open File Location”.


Big thanks to Eric Cain and Raffael Herrmann for enabling me to connect to the internet again :).