Definitely pass the data around. If you use global configuration (e.g. application env) it means
you have less flexibility, you only have one configuration and so you can’t configure this
connection with X and that connection with Y.
As others have mentioned you likely have some startlink/init/connect/new/whatever function, so accept configuration there and pass it around to further calls. And if passing options is annoying to the users of the library they can (and often should) wrap the library with their own module.
