Is the Canadian Experience Class a direct PR program, or do I still need an invitation?

The CEC is one of the three federal programs managed through the Express Entry system. Meeting the CEC eligibility requirements lets you enter the Express Entry pool, where candidates are ranked by the Comprehensive Ranking System (CRS). Only candidates who receive an Invitation to Apply (ITA) in a round of invitations can submit a permanent residence application. So qualifying for the CEC is necessary but not sufficient on its own; your CRS score relative to the cut-off in each draw determines whether you are invited.