Normal usage of toast should not require you to know how toast works internaly. But here is the source documentation anyway.
Salt entry points¶
This module contains the entry points for the salt adapters.
pillar(__opts__=None, minion_id=None, pillar=None, grains=None, **kwargs)¶
The main entry point for the ext_pillar extension
top(__opts__=None, grains=None, **kwargs)¶
The main entry point for the external_tops extension