In order that yarn still works behind a proxy server, you need to configure it accordingly. Because yarn doesn't use the environment variables HTTP_PROXY and HTTPS_PROXY, the proxy settings have to be set manually using the yarn config command (see the yarn config documentation for further details).

      yarn config set proxy http://proxy.domain.tld:port
      yarn config set https-proxy http://proxy.domain.tld:port
  

Replace proxy.domain.tld and port with the address and port of your proxy server. Notice the dash in the key https-proxy in contrast to the underscore in the name of the environment variables.

If your proxy server needs authentication, user name and password can be passed in the URL using the following syntax.

yarn config set proxy
http://username:password@proxy.domain.tld:port

If your credentials include an @ symbol, just put your user name and password inside quotes. If you use any other special characters in your credentials, you have to convert them into equivalent hexadecimal unicode.

Active Directory users have to pass their credentials in the URL as follows:

yarn config set
proxy http://domain\\username:password@proxy.domain.tld:port

Probably, you need to switch the protocol of the used registry from HTTPS to HTTP. Please check Section 5.15, “Changing the Yarn Registry” for further instructions.

Some node modules require files from GitHub, so you would have to configure git using a proxy in the same way:

git config --global http.proxy
http://username:password@proxy.domain.tld:port
git config --global https.proxy
http://username:password@proxy.domain.tld:port

Note

Many companies use a proxy auto-config (PAC) file which defines how browsers and other user agents choose the appropriate proxy server for fetching a given URL. Unfortunately neither yarn nor git support these files. As a workaround, you can install a local proxy server which uses a PAC file to decide how to forward a request.