I haven't seen any configuration option on the REST end point.Anyway loading a LiveCycle REST end point as a web page directly into a HTML browser is not a common real life scenario, is it?A typical architecture would include a web application and the REST end point would be invoked through a servle...

You can do that by adding a http header in the response, for instance in a servlet you would add: response.addHeader("content-disposition", "attachment; filename=" + myFileName + ".pdf")