Messaging does not have its own API calls, and is instead used as an umbrella for the different APIs involved with your business' messaging services. These include the Emails, Email Categories, Email Templates, Invitations and Events APIs, where email categories act as the groups of templates available for use by your business' communications, email templates are the template objects themselves, emails provide a means for you to send emails out from your business' account, invitations allow you to set up invitation campaigns and events allow you to set up automated messaging triggers.