I think this is the beauty of federation. Everything is open and free to all rather than a company being able to lock in your personally created content.
For example, I wanted to learn about NLP and am working on building a bot to monitor sentiment and check for hate speech in lemmy content. I am still at the brainstorming/research phase, but the accessibility of lemmy makes it really nice.
Pythorhead was made for this exact purpose.
Depending on what config data you need it might be a good idea to use environment variables. If all you need are server locations and credentials then environment variables are likely your best bet.
If you need fancy JSON or something else, global variables are nice.