How to invoke Cortana channel actions in node.js

Ugh.  It took me a while to figure it out, and I had to reverse engineer some code to do it. There were breadcrumbs, but of course being a newb it wasn't immediately obvious.

Botframework allows you to connect to channels. You are likely invoked from a channel. That means you can send meta-data back to that channel. In the previous version of the framework, you called a method off the Message called channelData to set the JSON response.  But channelData is deprecated in favor of the new sourceEvent method.  So forget the "Launching apps or websites from a Cortana skill" example (that is in C# and the old way)...

The next hint is in the documentation. sourceEvent takes a map.  The old version just took some action in a JSON with a type : LaunchUri and uri : "http://whatever.com/"

What is this map? Well, you can have your bot connected to one or more channels (or "*" for all.) The source code implementing sourceEvent was the final piece. I found examples setting the facebook channel, or using directline... But what is the channel name for Cortana?  Well, it is cortana.

Wrapping the JSON up underneath the channel name and magically Cortana will launch the app.

msg.sourceEvent( 
{ cortana : {
    action : { 
      type : "LaunchUri",
      uri : "https://www.octavianit.com"  
      }
    } 
  } )

But be careful as Cortana will close the channel after invoking the app (that the protocol maps to).  And you should consider that speakers (screenless devices) will not support this behavior and should have a UX alternative.