Client-provided operation ID
Server's task ID
Agent ID
Task type/tool name
Task status (completed, failed, needs_input, working, etc)
Optionalcontext_Server's context ID
OptionalmessageHuman-readable context about the status change
Timestamp
Optionalrawraw HTTP payload
Notification type
Optionalsequence_Sequence number of this notification
Optionalnext_When next notification is expected (not present for 'final')
Metadata for agent-initiated notifications Same as WebhookMetadata but includes notification-specific fields