You should already have your Harvest Media API key before attempting to connect!
Here’s the quick and dirty way to get your libraries and some albums:
from harvestmedia.api.client import Client
from harvestmedia.api.library import Library
client = Client(api_key)
# static methods need a client instance passed to them
# the convention for this is _client
libraries = Library.query.get_libraries(_client=client)
for library in libraries:
library_albums = library.get_albums()
More in the API docs!