ARC now support HTTP(S) proxy settings.
To enable proxy settings go to the application settings (ctrl/cmd + ,) and scroll down to the Proxy section.
Proxy settings section in Application settings
From here you can enable or disable proxy settings. To enable proxying you need to define the proxy URL. It can be an URL or an ID address. After enabling the proxy settings and providing the URL the application will start using the proxy to send the request.
Some proxies require authentication. If your proxy needs user credentials, enter the Proxy authentication option in the Proxy settings. This screen allows you to define the username and the password for the proxy.
Proxy authentication settings
Apply to all application
This option changes the behavior of the application by applying the proxy not only to the requests sent by the request editor but also to all requests outgoing from the application. This includes analytics (when allowed) and application updates (when enabled).
Detect and use system settings
On supported platforms (currently Windows only) it detects the proxy configuration and applies it to the application. When this is set you can skip the configuration of the proxy URL. When the configuration is found it is applied to the outgoing HTTP requests.