Postman Error: tunneling socket could not be established, statusCode=407

Question

I am using the desktop version of Postman at a client site to test an API. However, I am unable to access any SSL sites in Postman, such as the Git Hib API: https://api.github.com/users/karlgjertsen

However, I can make the same API call through Chrome, so this is Postman specific.

I assume it is down to proxy settings, but I am not sure how to view or update these in Postman. Has anyone had any experienced something similar?

Solution 1

I turned OFF both Global Proxy Configuration and Use System Proxy in Settings->Proxy tab in Postman and it started to work.

Solution 2

This solved my issue :

The option "Respect HTTP_PROXY, HTTPS_PROXY, and NO_PROXY environment variables." was selected by default in the proxy settings. I turned off this option and it worked for me.

Solution 3

Posting as the other solutions presented in this thread did not work in our corporate environment. We have a proxy configured on the network which uses Windows Default Credentials (username and password) for authentication. For whatever reason the browser knows how to pass these details with each request but postman does not by default.

Solution was to update the Default Proxy Configuration under settings -> proxy -> Default Proxy Configuration -> Tick 'This proxy requires authentication' then enter Windows Username and Password. Leave Use the system proxy and Add a custom proxy configuration settings disabled.

From the Windows start menu go to Change proxy settings and configure the host and port there.

Solution 4

Follow these steps on postman - Go to file=>Settings => Proxy (Tab) and uncheck the "Use System Proxy" checkbox. That should work

Solution 5

This turned out to be a local security policy that was applied to the machine in use. The local SSL proxy had a policy applied and it would not allow me to make a secure connection unless it was through a web browser.

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Comments

[Mikhail_Sam]

so there is no way to do it through the app? I just get the same error and I thought it is because of proxy too. But my administrator don't let to install chrome extension, so I'm confused...

[Chris]

Where can you check for this in the local security policy?

[Karl Gjertsen]

The local policy was added by the IT team and I had to request an exemption. Typical issue you will run in to in a corporate environment.

[Allan Ramirez]

this worked for me. I disabled the option Use System Proxy

[Sveta Fishka]

merci! it was also the right way for me