Interface StreamingEventKind_v0_3

All Superinterfaces:

Event_v0_3

All Known Implementing Classes:

Message_v0_3, Task_v0_3, TaskArtifactUpdateEvent_v0_3, TaskStatusUpdateEvent_v0_3

public sealed interface StreamingEventKind_v0_3
extends Event_v0_3
permits Task_v0_3, Message_v0_3, TaskStatusUpdateEvent_v0_3, TaskArtifactUpdateEvent_v0_3

Sealed interface for events that can be emitted during streaming A2A Protocol operations.

StreamingEventKind represents events suitable for asynchronous, progressive updates during agent task execution. Streaming allows agents to provide incremental feedback as work progresses, rather than waiting until task completion.

Streaming events use polymorphic JSON serialization with the "kind" discriminator to determine the concrete type during deserialization.

Permitted implementations:

• Task_v0_3 - Complete task state (typically the final event in a stream)
• Message_v0_3 - Full message (complete message in the stream)
• TaskStatusUpdateEvent_v0_3 - Incremental status updates (e.g., SUBMITTED → WORKING → COMPLETED)
• TaskArtifactUpdateEvent_v0_3 - Incremental artifact updates (partial results, chunks)

Streaming events enable patterns like:

• Progressive text generation (chunks of response as generated)
• Status notifications (task state transitions)
• Partial results (early artifacts before task completion)

See Also:

• Event_v0_3
• EventKind_v0_3
• UpdateEvent_v0_3

Method Summary

Modifier and Type	Method	Description
String	kind()

Method Details

kind

String kind()