How to access in-game data?

Is there a way to read the current in-game data, like player's HP or AC (`u.uhp`, `u.uac` from `struct you`) and level object data from the generated JS code? I've seen the `create_global` function that looks like it makes a setter/getter that references a set pointer but I couldn't find any examples on how is it used and how to get global struct offsets of the game.