API or Alexa Routine to add temporary user

I see a lot of requests for HomeKit integration. I would even be happy with a simple API we can use to create a new user with time limits. That way, I can add users programmatically whenever an Airbnb booking is made with the code they should be using. Or even an Alexa Routine that can do that (I can kick off Alexa programmatically just fine)

This is totally a thing already