title: Amazon API Gateway : response body is not transformed when the API is called via Postman?
body: <p>When executing a testvia the AWS API Gateway console, I see that the output response from the Lambda function is correctly transformed:</p>
  
  <pre><code>{
    "type" : "",
    "message" : "",
    "request-id" : ""
  }
  </code></pre>
  
  <p>See logs below:</p>
  
  <pre><code>Tue Sep 06 14:46:06 UTC 2016 : Endpoint request body after transformations: {}
  Tue Sep 06 14:46:06 UTC 2016 : Endpoint response body before transformations: {"errorMessage":"501stef"}
  Tue Sep 06 14:46:06 UTC 2016 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=a4540f42-7440-11e6-90ce-214b29fcde38, Connection=keep-alive, Content-Length=26, Date=Tue, 06 Sep 2016 14:46:06 GMT, Content-Type=application/json}
  Tue Sep 06 14:46:06 UTC 2016 : Method response body after transformations: {
    "type" : "",
    "message" : "",
    "request-id" : ""
  }
  Tue Sep 06 14:46:06 UTC 2016 : Method response headers: {Content-Type=application/json}
  Tue Sep 06 14:46:06 UTC 2016 : Successfully completed execution
  Tue Sep 06 14:46:06 UTC 2016 : Method completed with status: 501
  </code></pre>
  
  <p><br></p>
  
  <hr>
  
  <p>However when calling the API via Postman with headers:</p>
  
  <pre><code>Content-Type : application/json
  Accept : application/json
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/tnhTa.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tnhTa.png" alt="enter image description here"></a></p>
  
  <p>No output transformation is happening, and the output JSON message is just:</p>
  
  <pre><code>{
    "errorMessage": "501stef"
  }
  </code></pre>
  
  <p><br>Partly related to <a href="https://stackoverflow.com/questions/33516225/amazon-api-gateway-fails-to-generate-transformed-request">Amazon APi gateway fails to generate transformed request</a> but this one talks about the <strong>Request</strong>.</p>