NT Productions shows how to write a JSON file, then later read it with a script.

NT Productions adds another tutorial for working with Adobe ExtendScript that shows how you can read and write JSON files using a script. JSON (Javascript Object Notation) is the perfect file format for sharing information between applications. It is an open-standard file format that you can use to store and transport data in a text file, that is reasonably legible. That means that the data is in attribute-value pairs and array data types rather than code. 

NT Production’s Nathan Lovell walks through how to write a JSON file and then later read it with a script, using ExtendScript. Check out this other tutorial from Sergei Prokhnevskiy that shows how you can make use of JSON with After Effects.