@Krest01 ytmdl is not aimed as a library (thus no docs regarding the API) though it can be used as one without any issue.

For starters, I would suggest you to go over the source code to find out the various functions that ytmdl provides. As a starting point, you can look at ytmdl/main.py. This is where the entry for the app is and from here you will understand the flow of ytmdl. Based on that you will also be able to find the functions that you want for your usecase.

There is a core.py file in the ytmdl directory. This file contains most of the top-level functions that main.py uses. This file can be thought of as the container for top-level pipeline stages where various stages are searching, metadata searching, extracting, downloading etc.

As I said, the best way to go about would be to look at the main.py and start from there.

Once you have gone through that, if you need any inputs on specific functions and how a particular function actually works, you can let me know, I will be happy to explain!