I have a very basic plugin working in Indigo.  It serves a single threaded basic webserver on port 5000 and will list devices from indigo.  Also has basic auth enabled using credentials in settings.py

I think I might need a more robust way to serve the webserver, but so far indigo doesnt seem to like multithreaded serving in the plugin process.

Long term I think its going to be best to run nginx->gunicorn->indigo, and possibly bypass the indigo server plugin.