REST Datasource connection to External system

Hey Zach,  

Thanks for the solution and this works absolutely perfect.

However, the requirement here is a bit different, the external endpoint is a single POST endpoint returning 201 response on successful execution. There is no extra GET endpoint to know the response fields. The problem statement here is to send whatever changed on the skuid page to be sent as a JSON object to the external post endpoint. Is there a way to use just query with POST or Insert or Update with POST method to send these details through. I tried using just query with POST but struggling to identify how to send the custom request body of changed items.
Any help would be appretiated.

Thanks
Mayank