Configuring NPM to use Nexus as a proxy is simple.

First ensure you've created the NPM proxy.

Next, edit or create the file .npmrc in your home directory with the following line:

1registry=http://10.11.12.13:8081/repository/npm-proxy

Where 10.11.12.13 is where you have deployed Nexus and npm-proxy is what you called your NPM proxy. If you've configured a group then use the group's name instead, e.g. npm-group

Obviously if you've configured https and dns then use that and not port 8081.

Now any time you run npm it will use your proxy.