I just tried this out with a Lambda function; I was wondering why you can't serve HTML with this (Yes, I know this product is aimed at enterprise ReST API stuff... one can try at least).

Well, it seems that authentication for the client is mandatory. This makes it unsuitable for rendering markup and serving it directly to clients.

Can anyone confirm this can only serve JSON content? I suspect were anonymous requests allowed, I'd see my markup rendered as a JSON string.