a2a.server.request_handlers.default_request_handler module

class a2a.server.request_handlers.default_request_handler.LegacyRequestHandler(agent_executor: AgentExecutor, task_store: TaskStore, agent_card: AgentCard, queue_manager: QueueManager | 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.

This handler provides default implementations for all A2A JSON-RPC methods, coordinating between the AgentExecutor, TaskStore, QueueManager, and optional PushNotifier.

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

Default handler for ‘tasks/cancel’.

Attempts to cancel the task managed by the AgentExecutor.

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

Default handler for ‘tasks/pushNotificationConfig/create’.

Requires a PushNotifier to be configured.

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

Default handler for ‘tasks/pushNotificationConfig/delete’.

Requires a PushConfigStore to be configured.

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

Default handler for ‘tasks/get’.

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

Default handler for ‘tasks/pushNotificationConfig/get’.

Requires a PushConfigStore to be configured.

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

Default handler for ‘ListTaskPushNotificationConfigs’.

Requires a PushConfigStore to be configured.

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

Default handler for ‘tasks/list’.

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

Default handler for ‘message/send’ interface (non-streaming).

Starts the agent execution for the message and waits for the final result (Task or Message).

on_message_send_stream(params: SendMessageRequest, context: ServerCallContext) → AsyncGenerator[Message | Task | TaskStatusUpdateEvent | TaskArtifactUpdateEvent]

Default handler for ‘message/stream’ (streaming).

Starts the agent execution and yields events as they are produced by the agent.

on_subscribe_to_task(params: SubscribeToTaskRequest, context: ServerCallContext) → AsyncGenerator[Message | Task | TaskStatusUpdateEvent | TaskArtifactUpdateEvent, None]

Default handler for ‘SubscribeToTask’.

Allows a client to re-attach to a running streaming task’s event stream. Requires the task and its queue to still be active.