This seems to be more node.js related than SN related. Not sure why you're getting back HTML but I'm pretty sure that your request.post call is not formed correctly. Typically with these request functions the first argument you supply is a json object with the url, headers and body. You would also need to supply authentication data since you're looking to create records. Also, be sure you're including an "Accept" header set to "application/json" to ensure the response you get back is formatted as a json object.