So looking through the functions, I noticed a function called GetFileData().

I'm looking to create a save file system that is separate from the default .quest-save. Mostly for different version compatibility, so people can update the game and not lose their save files.

Is there an output equivalent of GetFileData()? Maybe something like CreateFile(name, contents) and AppendFile() that would put a file in the game folder I can fill with text? Or some way to replicate creating a text file with Javascript?

There is no function to do. It might be possible to use JavaScript, but the security issue means it probably will not work on the on-line version.

I don't mind if it doesn't work in the online version, I usually only make and play my games in the offline version. I've looked around javascript for a while, not seen anything that wouldn't require the player to download a seperate API.