#should-proxy should-proxy uses a no_proxy list formatted like so localhost,127.0.0.0/8,10.0.0.0/8,192.168.0.0/16,172.16.0.0/12,.internal.com To determine if a url should be proxied or not. should-proxy is a function that takes a url as well as options. If no options are provided should-proxy uses the environment variable no_proxy Usage var shouldProxy = require('should-proxy'); var result = shouldProxy("http://something.google.com/", { no_proxy: "google.com" }); // Should be false, because google.com is on the no_proxy list provided console.log("http://something.google.com/", result); result = shouldProxy("http://localhost/", { no_proxy: "" }); // Should be true, because localhost is not the no_proxy list provided console.log("http://localhost/", result); // Omitting the options object will cause should-proxy // to use process.env["no_proxy"]