a2a.server.request_handlers.default_request_handler_v2 module

class a2a.server.request_handlers.default_request_handler_v2.DefaultRequestHandlerV2(agent_executor: AgentExecutor, task_store: TaskStore, agent_card: AgentCard, queue_manager: Any | None = None, push_config_store: PushNotificationConfigStore | None = None, push_sender: PushNotificationSender | None = None, request_context_builder: RequestContextBuilder | None = None, extended_agent_card: AgentCard | None = None, extended_card_modifier: Callable[[AgentCard, ServerCallContext], Awaitable[AgentCard]] | None = None)

Bases: RequestHandler

Default request handler for all incoming requests.

async on_cancel_task(params: CancelTaskRequest, context: ServerCallContext) → Task | None

Handles the ‘tasks/cancel’ method.

Requests the agent to cancel an ongoing task.

Parameters:

  • params – Parameters specifying the task ID.

  • context – Context provided by the server.

Returns:

The Task object with its status updated to canceled, or None if the task was not found.

async on_create_task_push_notification_config(params: TaskPushNotificationConfig, context: ServerCallContext) → TaskPushNotificationConfig

Handles the ‘tasks/pushNotificationConfig/create’ method.

Sets or updates the push notification configuration for a task.

Parameters:

  • params – Parameters including the task ID and push notification configuration.

  • context – Context provided by the server.

Returns:

The provided TaskPushNotificationConfig upon success.

async on_delete_task_push_notification_config(params: DeleteTaskPushNotificationConfigRequest, context: ServerCallContext) → None

Handles the ‘tasks/pushNotificationConfig/delete’ method.

Deletes a push notification configuration associated with a task.

Parameters:

  • params – Parameters including the task ID.

  • context – Context provided by the server.

Returns:

None

async on_get_extended_agent_card(params: GetExtendedAgentCardRequest, context: ServerCallContext) → AgentCard

Default handler for ‘GetExtendedAgentCard’.

Requires capabilities.extended_agent_card to be true.

async on_get_task(params: GetTaskRequest, context: ServerCallContext) → Task | None

Handles the ‘tasks/get’ method.

Retrieves the state and history of a specific task.

Parameters:

  • params – Parameters specifying the task ID and optionally history length.

  • context – Context provided by the server.

Returns:

The Task object if found, otherwise None.

async on_get_task_push_notification_config(params: GetTaskPushNotificationConfigRequest, context: ServerCallContext) → TaskPushNotificationConfig

Handles the ‘tasks/pushNotificationConfig/get’ method.

Retrieves the current push notification configuration for a task.

Parameters:

  • params – Parameters including the task ID.

  • context – Context provided by the server.

Returns:

The TaskPushNotificationConfig for the task.

async on_list_task_push_notification_configs(params: ListTaskPushNotificationConfigsRequest, context: ServerCallContext) → ListTaskPushNotificationConfigsResponse

Handles the ‘ListTaskPushNotificationConfigs’ method.

Retrieves the current push notification configurations for a task.

Parameters:

  • params – Parameters including the task ID.

  • context – Context provided by the server.

Returns:

The list[TaskPushNotificationConfig] for the task.

async on_list_tasks(params: ListTasksRequest, context: ServerCallContext) → ListTasksResponse

Handles the tasks/list method.

Retrieves all tasks for an agent. Supports filtering, pagination, ordering, limiting the history length, excluding artifacts, etc.

Parameters:

  • params – Parameters with filtering criteria.

  • context – Context provided by the server.

Returns:

The ListTasksResponse containing the tasks.

async on_message_send(params: SendMessageRequest, context: ServerCallContext) → Message | Task

Handles the ‘message/send’ method (non-streaming).

Sends a message to the agent to create, continue, or restart a task, and waits for the final result (Task or Message).

Parameters:

  • params – Parameters including the message and configuration.

  • context – Context provided by the server.

Returns:

The final Task object or a final Message object.

on_message_send_stream(params: SendMessageRequest, context: ServerCallContext) → AsyncGenerator[Event, None]

Handles the ‘message/stream’ method (streaming).

Sends a message to the agent and yields stream events as they are produced (Task updates, Message chunks, Artifact updates).

Parameters:

  • params – Parameters including the message and configuration.

  • context – Context provided by the server.

Yields:

Event objects from the agent’s execution.

on_subscribe_to_task(params: SubscribeToTaskRequest, context: ServerCallContext) → AsyncGenerator[Event, None]

Handles the ‘SubscribeToTask’ method.

Allows a client to subscribe to a running streaming task’s event stream.

Parameters:

  • params – Parameters including the task ID.

  • context – Context provided by the server.

Yields:

Event objects from the agent’s ongoing execution for the specified task.