Read/write files on server from server methods



I am not an expert in digging package code (yet, sorry).

I wish to read/write from server methods only,
object definitions in plain text such as those in schema definitions in Simple Schema or i18n packages.

Some cases for data driving the app,
Some data for user content
Some for displaying program code from the app folder tree…

  1. What API could be the best straight forward (not shure if FScollection is necessary if I already manage meta data in my app).

  2. How can I be shure only server methods can access them (read/write)?
    (I do not wich to play with a 3rd party server for that, such as with Slingshut package)

  3. Best folder location for that?

I am using a structure using ES6 import/export pattern.
And I wish the software can modify such files from an Editing UI that I will program.