Hey @Alvaro_Ferrer, thanks for checking out Streamlit, and welcome to the community!
Internally, Streamlit uses Tornado to serve HTTP and WebSocket data to its frontend. That is, it’s already its own web server, and is written in an existing web framework; it wouldn’t be trivial to wrap it inside another web framework.
(It’s probably possible to refactor Streamlit to use Flask instead of Tornado, but perhaps not worth the trouble?)
Can you give some more detail about what you’re trying to accomplish?