Is there an API for character sheets one could use?

I want to explore the possibility of building native mobile apps for FoundryVTT character sheets. My question is if there is an API I could developer against when it comes to what’s on the character sheet?

A first step would be to just interface towards the data and present the character sheet without any real interactivity. (No dice rolling, or changing hp and having that potentially sync with the map) Just a nifty place to have your character sheet if you say wanna use foundryVTT as the map for your local, at the table game.

Outside of the character sheet, a completely functional app would allow you to see the chat, character sheet, and at most (luxury feature) maybe any handouts connected to your player.