Tokens, you can immediately say you will get styling code to be used in your Flutter codebase. When developing exporters, you have a complete control over everything defined inside exporters and how they should generate the resulting code.
Flutterexporter Supernova team prepared for you (you can get it right from Exporter Store):
exporter.json. This contains metadata about the exporter package such as name, author or description that will show up in the exporter store or anywhere the exporter is used (for example, by your collagues).
output.json. This file contains mapping of what files should be produced when exporter runs and how it maps to the code you have created.
sources.jsonto tweak it. Most often, you will use default configuration for each file you are generating, so this is optional.