Can AWS API Gateway support `application/x-www-form-urlencoded` with body and query string parameters?

Question

Numerous services can accept query string parameters in the URL when a POST request is made with Content-Type: application/x-www-form-urlencoded and other parameters in the body, but it seems AWS API Gateway cannot while also accepting query string parameters.

When I call the AWS API Gateway with a POST Mapping Template for application/x-www-form-urlencoded and query string URL parameters (with a Lambda function), I get the following error:

{
  "message":"When Content-Type:application/x-www-form-urlencoded,
    URL cannot include query-string parameters (after '?'):
    '/prod/webhook?inputType=wootric&outputType=glip&url=...'"
}

Here is an example cURL:

curl -XPOST 'https://{myid}.execute-api.{myregion}.amazonaws.com/prod/webhook? \
inputType=wootric&outputType=glip&url=https://hooks.glip.com/webhook/ \
11112222-3333-4444-5555-666677778888' \
-d "@docs/handlers/wootric/event-example_response-created.txt" \
-H 'Content-Type: application/x-www-form-urlencoded' -v

The specific goal is to get a Wootric webhook event posted to a Lambda function using a URL with query string parameters.

You can get the code here:

https://github.com/grokify/chathooks

The Wootric event body file is here:

https://raw.githubusercontent.com/grokify/chathooks/master/docs/handlers/wootric/event-example_response-created.txt

The GitHub issue is here:

https://github.com/grokify/chathooks/issues/15

The error message seems pretty definitive but I wanted to ask:

1. Is there a workaround to configure an API Gateway to support both?
2. Is there a standards-based reason why AWS would not support this or is this just a design decision / limitation?

If there's no solution to this, is there a good lightweight solution other than deploying a hosted server solution like Heroku. Also, do other cloud services support this with their API gateway + cloud functions, like Google?

Some examples showing support for both:

• jQuery example: jQuery send GET and POST parameters simultaneously at AJAX request
• C# example: Accessing query string variables sent as POST in HttpActionContext

Answer 1

Yes,there is a workaround and the key issue is to set the mapping template that will convert string into json . Very detailed example shown in API Gateway any content type.