Type of notification
Optionalsequence_Sequential notification number (starts at 1)
Optionalnext_When next notification is expected (omitted for 'final')
Optionalreporting_Reporting period for this notification
OptionalcurrencyCurrency used for financial metrics
Optionalmedia_Array of media buy deliveries being reported
Media buy delivery notification payload (PR #81) Agent-initiated periodic reporting, not tied to any client operation