Can blueprints use html files?

In order to make full use of the AUI, I would like to use an html file instead of an xml file to dev a confluence cloud blueprint. I’ve tried updating the atlassian-connect.json & index.js files but the blueprint fails to load, throwng an error that an xml file was expected.

Any ideas where else the code needs to be updated?
All help is appreciated.

I don’t think HTML is supported, but you could probably use soy-templates in your plugin to build HTML elements.

Take a look here at the documentation:

Thanks for the feedback and links to more details.
Will check it out.