CloudSponge Proxy URL for Instapage

body.html

    <p>Thank you for completing the OAuth flow.</p>
    <p>Click <a class="cs-force">here to verify that your Proxy URL is set up correctly</a>.</p>

head.html

    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>OAuth Proxy Page</title>
    <!-- Including the CloudSponge proxy script here to redirect to the CloudSponge server -->
    <script>
      // This auth-proxy.js can be placed on any HTML page to turn it into a
      //  CloudSponge Proxy URL. 
      // It pulls the proper OAuth parameters out and sends them to CloudSponge
      //  to complete the next stage in the contact import. 
      window.cloudspongeProxy = (function() {
        var proxyHost = 'https://api.cloudsponge.com/auth';
        var isOAuthPage, queryParams, oauthParams, key;
        var redirecting = false;
        
        function appendSearch() {
          var search = window.location.search;
          if (search && search[0] == '?') {
            search = search + "&"
          } else {
            search = search + '?'
          }
          search = search + "state=_csAuth%3D1%26import_id%3Dproxy-test";
          return search;
        }
        // serializes an object into a query-string
        var serializeParams = function(params) {
          var k, results = [];
          for (k in params) {
            results.push(k + "=" + encodeURIComponent(params[k]));
          }
          return results.join('&');
        }
      
        // converts the URL string into an object
        var parseParams = function(url) {
          var obj = {};
          url.replace(/([^?=&]+)(=([^&]*))?/g, function($0, $1, $2, $3) {
            return obj[$1] = decodeURIComponent($3);
          });
          return obj;
        }
      
        // parse the query string
        var queryParams = parseParams(window.location.search);
      
        // selects just the OAuth-related params out of the query
        oauthParams = {};
        for (key in queryParams) {
          if (key === 'code' || key === 'state' || key === 'error' || key === 'error_code' || key === 'forward') {
            oauthParams[key] = queryParams[key];
          }
        }
      
        // checks to see if this page actually the necessary received OAuth params
        // and then flings the state and code up to CloudSponge to do the heavy lifting work
        if (oauthParams.state && (oauthParams.code || oauthParams.error || oauthParams.error_code)) {
          redirecting = true;
          window.location = proxyHost + '?' + serializeParams(oauthParams);
        }
      
        // add the redirect endpoint to any .cs-proxy links on the page
        window.addEventListener('load', function(){
          var i;
          var links = document.getElementsByClassName('cs-force');
          for (i = 0; i < links.length; i++) {
            links[i].href = proxyHost + appendSearch();
          }
        }, false)
      
        return {
          redirecting: redirecting,
          force: function(){
            window.location = proxyHost + appendSearch();
            return false;
          }
        };
      })();
    </script>

Here is the Proxy URL content, split for setting up with Instapage. Hopefully, this helps to reduce any errors when copying and pasting the code snippets.