title: Alexa appliance discovery in custom skill
body: <p>I have been checking around on this topic, but have not seen a concrete solution on how to get it working. I am building a Custom Skill for Alexa, which currently supports speech. Now I would like to extend the skill with video streaming to a TV.
  The only thing the Custom Skill seems to support for this is streaming to Echo Show with the VideoApp directives?</p>
  
  <p>I have seen answers that say it is possible, just return a list of devices, but these devices and their appliance id's seem to be hardcoded, I would need to get an actual list of devices linked to the users account.</p>
  
  <p>So the question is: is it actually possible to incorporate Video Skill functionality (and device discovery) in a custom skill, or would it need to be a separate skill?</p>