a2a.server.tasks.task_updater module

class a2a.server.tasks.task_updater.TaskUpdater(event_queue: EventQueue, task_id: str, context_id: str, artifact_id_generator: IDGenerator | None = None, message_id_generator: IDGenerator | None = None)

Bases: object

Helper class for agents to publish updates to a task’s event queue.

Simplifies the process of creating and enqueueing standard task events.

async add_artifact(parts: list[Part], artifact_id: str | None = None, name: str | None = None, metadata: dict[str, Any] | None = None, append: bool | None = None, last_chunk: bool | None = None, extensions: list[str] | None = None) → None

Adds an artifact chunk to the task and publishes a TaskArtifactUpdateEvent.

Parameters:

  • parts – A list of Part objects forming the artifact chunk.

  • artifact_id – The ID of the artifact. A new UUID is generated if not provided.

  • name – Optional name for the artifact.

  • metadata – Optional metadata for the artifact.

  • append – Optional boolean indicating if this chunk appends to a previous one.

  • last_chunk – Optional boolean indicating if this is the last chunk.

  • extensions – Optional list of extensions for the artifact.

async cancel(message: Message | None = None) → None

Marks the task as cancelled and publishes a finalstatus update.

async complete(message: Message | None = None) → None

Marks the task as completed and publishes a final status update.

async failed(message: Message | None = None) → None

Marks the task as failed and publishes a final status update.

new_agent_message(parts: list[Part], metadata: dict[str, Any] | None = None) → Message

Creates a new message object sent by the agent for this task/context.

Note: This method only creates the message object. It does not

automatically enqueue it.

Parameters:

  • parts – A list of Part objects for the message content.

  • metadata – Optional metadata for the message.

Returns:

A new Message object.

async reject(message: Message | None = None) → None

Marks the task as rejected and publishes a final status update.

async requires_auth(message: Message | None = None, final: bool = False) → None

Marks the task as auth required and publishes a status update.

async requires_input(message: Message | None = None, final: bool = False) → None

Marks the task as input required and publishes a status update.

async start_work(message: Message | None = None) → None

Marks the task as working and publishes a status update.

async submit(message: Message | None = None) → None

Marks the task as submitted and publishes a status update.

async update_status(state: TaskState, message: Message | None = None, final: bool = False, timestamp: str | None = None, metadata: dict[str, Any] | None = None) → None

Updates the status of the task and publishes a TaskStatusUpdateEvent.

Parameters:

  • state – The new state of the task.

  • message – An optional message associated with the status update.

  • final – If True, indicates this is the final status update for the task.

  • timestamp – Optional ISO 8601 datetime string. Defaults to current time.

  • metadata – Optional metadata for extensions.