cloudformation-create-request.json

{
  "RequestType": "Create",
  "ResponseURL": "http://pre-signed-S3-url-for-response",
  "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/MyStack/guid",
  "RequestId": "unique id for this create request",
  "ResourceType": "Custom::TestResource",
  "LogicalResourceId": "MyTestResource",
  "ResourceProperties": {
    "StackName": "MyStack",
    "List": [
      "1",
      "2",
      "3"
    ]
  }
}