It provides transparent caching, helper functionality, error handling, and credentials management. It is a unified place for sharing "business logic" for handling Bugs, People, Projects, Blueprints, and more.

It's fairly easy to write scripts using just launchpadlib itself. But launchpadlib-toolkit provides a number of helpful features to make it easier to write larger scripts. It provides a standardized mechanism for handling credentials and cache files, and provides in-memory caching of the LP request data. It also includes various helper routines for useful, general purpose functionality, such as converting bug dates to ages, unicode conversions, etc.