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Troubleshooting Proxies

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Learn about troubleshooting proxies with a set of recommended tools.

macOS proxy configuration (Sierra)

If anything goes wrong, you can revert to the "Automatic Proxy settings" in System Network Preferences using Automatic Proxy Configuration your-corporate-proxy-uri:port-number/proxy.pac.


To run this in the local iOS Simulator while on your corporate Wi-Fi network, a local proxy manager is required. You can use a local proxy application such as Charles.

Open macOS network preferences

  1. Open System Preferences for your Mac (Apple Menu > System Preferences).
  2. Go to Network.
  3. Be sure your Location is set to your proxy network, and not "Automatic".
  4. With Wi-Fi selected on the left and/or ethernet connection, click Advanced... on the bottom right side of the window.

Configure proxy address

  1. Disable/uncheck "Automatic Proxy Configuration" if it is set.
  2. Check "Web Proxy (HTTP)" and set "Web Proxy Server" to : 8888
  3. Check "Secure Web Proxy (HTTPS)" and set "Secure Web Proxy Server" to : 8888

Configure Charles

  1. Open Charles

  2. If it asks, don't allow it to manage your macOS Network Configuration, the previous steps do that. (If you change Charles port, update the previous step to the correct port instead of default 8888)

  3. In the menu of Charles go to Proxy > External Proxy Settings, check Use external proxy servers

  4. Check Web Proxy (HTTP), and enter your-corporate-proxy-uri:port-number

  5. Check Proxy server requires a password


  7. Same for Secure Web Proxy (HTTPS). Be sure to fill in the same proxy, username, and password address fields.

  8. In the text area for Bypass external proxies for the following hosts: enter:


    You may need to include your mail server or other corporate network addresses.

  9. Check "Always bypass external proxies for localhost"

iOS Simulator configuration

If you have an existing iOS Simulator custom setup going that is not working, "Simulator > Reset Content and Settings" from the menu.

If you have the Simulator open still, quit it.

Now, in Charles under the "Help" menu > Install Charles Root Certificate, and then again for Install Charles Root Certificate in iOS Simulators

Technical note: This whole process is required because the iOS Simulator is served a bum proxy certificate instead of the actual certificate, and doesn't allow it, for https://exp.host/ which is required to run Expo.
Also note: Configure applications that need internet access, such as Spotify, to use http://localhost:8888 as your proxy. Some apps, such as Chrome and Firefox, you can configure in the settings to use your "System Network Preferences" which will use Charles : 8888, or no proxy, depending on how you have your "Location" set in the Apple menu/network preferences. If you are set to "Automatic" no proxy is used, if it is set to "your proxy network" the proxy is used and Charles will need to be running.

Command line application proxy configuration

npm, git, Brew, Curl, and any other command line applications need proxy access too.

For npm

Open ~/.npmrc and set:


For git

Open ~/.gitconfig and set

  proxy = http://localhost:8888
  proxy = http://localhost:8888

For command line applications

Depending on your shell, and config, Open ~/.bashrc, ~/.bash_profile, or ~/.zshrc or wherever you set your shell variables and set:

export HTTP_PROXY="http://localhost:8888"
export http_proxy="http://localhost:8888"
export ALL_PROXY="http://localhost:8888"
export all_proxy="http://localhost:8888"
export HTTPS_PROXY="http://localhost:8888"
export https_proxy="http://localhost:8888"

If you switch your network location back to "Automatic" to use npm or git, you will need to comment these lines out using a # before the line you wish to disable. You could alternatively use a command-line proxy manager if you prefer.