Archived from the Transloadit support forum. Originally posted on March 28, 2012; details may be outdated, see our docs for current behavior. Original thread
How do we authenticate the notify_url response?
You mean that the notify url is signed with a signature so that you can be certain it was Transloadit that sent you the notification?
I was thinking more like basic authentication, but embedding a return code in the url might work.
Added to todo list. Closing this for now.