AWS API Gateway: Use Mock Integration to echo response body

Question

I am trying to use the Mock integration to just "echo" back me the JSON body that I sent. However, I just can't get it to work. I can return any arbitrary JSON body from my "POST - Integration Response", but the request JSON is never found via $input.json('$'). I have been able to successfully echo back any query parameters.

My API has a single "/" path and a single method defined (POST). The exported yaml is here .

Any idea as to what may be going on?

Answer 1

I've found this to actually be possible, although a little hacky. First, in the integration request mapping template you store the body in a path parameter.

#set($context.requestOverride.path.body = $input.body)
{
  "statusCode": 200,
}

Then in the integration response mapping template you fetch it back and return it.

#set($body = $context.requestOverride.path.body)
{
  "statusCode": 200,
  "body": $body,
}

This seems to even work well with larger payloads.

Answer 2

Unfortunately this is not supported. In the mapping template for "Integration Response", $input represents the payload received from the integration response (which is empty in the case of a MOCK integration.