title: Why do I get invalid JSON payload when calling google cloud vision API from appcelerator?
body: <p>I was trying to use Google vision API v1 by Alloy Appcelerator</p>
  
  <p>I create a request HTTPClient and call API <a href="https://vision.googleapis.com/v1/images:annotate?key=MY_APP_KEY" rel="nofollow">https://vision.googleapis.com/v1/images:annotate?key=MY_APP_KEY</a></p>
  
  <p>But i have get response text from google :</p>
  
  <pre><code>  {
   error = {
       code = 400;
       details = (
                    {
                       "@type" = "type.googleapis.com/google.rpc.BadRequest";
                        fieldViolations = ({
                                          description = "Invalid JSON payload received. Unknown name \"request\": Cannot bind query parameter. Field 'request' could not be found in request message.";
                                          });
                    }
                  );
       message = "Invalid JSON payload received. Unknown name \"request\": Cannot bind query parameter. Field 'request' could not be found in request message.";
       status = "INVALID_ARGUMENT";
    };
  </code></pre>
  
  <p>}</p>
  
  <p>And there is my code use HTTP request by Alloy</p>
  
  <pre><code>var requests =  
  {
    "requests":[
      {
        "image":{
          "content": "image_have_encodebase64",
        },
        "features":[
          {
            "type":"TEXT_DETECTION",
            "maxResults":1
          }
        ]
      }
    ]
  };
  var xhr = Titanium.Network.createHTTPClient();
  xhr.open("POST", 'https://vision.googleapis.com/v1/images:annotate?key=MY_APP_KEY');
  xhr.send(JSON.stringify(requests));
  </code></pre>
  
  <p>Thanks for your help</p>