Calling Amazon API from iOS app is failing

I'm attempting to make an Amazon API call like so:

        console.log('about to define AmazonHttpRequestPromise');

        var AmazonHttpRequestPromise = Parse.Cloud.httpRequest({
            url: url,
            params: {
              'AWSAccessKeyId': '*ACCESS KEY GOES HERE*',
              'AssociateTag': '*ASSOCIATE TAG GOES HERE*',
              'Keywords': 'harry+potter',
              'Operation': 'ItemSearch',
              'SearchIndex': 'Books',
              'Service': 'AWSECommerceService',
              'Version': '2013-08-01',
            }
          });

          console.log('AmazonHttpRequestPromise looks like this:' + AmazonHttpRequestPromise);

        return AmazonHttpRequestPromise;

I've set up the error message to work like this:

function (err) {
          console.log('error!' + err);
          response.error('DAMN IT MAN');
        } 

and as a result, the error message it returns is this:

error![object Object],[object Object]

am I setting up the call incorrectly? I can't figure out where I'm going wrong.