I'd like to use an external RAG backend with OpenWebUI as its front-end. What feature will be most useful?

There's a bunch of very cool RAG repos like this one https://github.com/Future-House/paper-qa and a bunch more from Llama-Index that I'd like to try out and use OWebUI as the frontend instead of a clunky streamlit chat app. Is this possible? How would I go about it? Thanks!