feat: Support for list and delete push notification config (#222)

Support for list and delete push notification config.

Removes the push_notifier from the SDK.

This will be merged into push_notif_refactoring branch
(#212) and then merged into
main along with refactoring changes.

---------

Co-authored-by: Holt Skinner <13262395+holtskinner@users.noreply.github.com>

Author: kthota-g

src/a2a/server/apps/jsonrpc/jsonrpc_app.py

@@ -39,6 +39,8 @@
     SetTaskPushNotificationConfigRequest,
     TaskResubscriptionRequest,
     UnsupportedOperationError,
+    ListTaskPushNotificationConfigRequest,
+    DeleteTaskPushNotificationConfigRequest
 )
 from a2a.utils.errors import MethodNotImplementedError
 
@@ -297,12 +299,22 @@ async def _process_non_streaming_request(
                     request_obj, context
                 )
             case SetTaskPushNotificationConfigRequest():
-                handler_result = await self.handler.set_push_notification(
+                handler_result = await self.handler.set_push_notification_config(
                     request_obj,
                     context,
                 )
             case GetTaskPushNotificationConfigRequest():
-                handler_result = await self.handler.get_push_notification(
+                handler_result = await self.handler.get_push_notification_config(
+                    request_obj,
+                    context,
+                )
+            case ListTaskPushNotificationConfigRequest():
+                handler_result = await self.handler.list_push_notification_config(
+                    request_obj,
+                    context,
+                )
+            case DeleteTaskPushNotificationConfigRequest():
+                handler_result = await self.handler.delete_push_notification_config(
                     request_obj,
                     context,
                 )

src/a2a/server/request_handlers/default_request_handler.py

@@ -39,6 +39,10 @@
     TaskPushNotificationConfig,
     TaskQueryParams,
     UnsupportedOperationError,
+    ListTaskPushNotificationConfigParams,
+    DeleteTaskPushNotificationConfigParams,
+    DeleteTaskPushNotificationConfigResponse,
+    DeleteTaskPushNotificationConfigSuccessResponse
 )
 from a2a.utils.errors import ServerError
 from a2a.utils.telemetry import SpanKind, trace_class
@@ -393,11 +397,11 @@ async def on_get_task_push_notification_config(
             raise ServerError(error=TaskNotFoundError())
 
         push_notification_config = await self._push_config_store.get_info(params.id)
-        if not push_notification_config:
+        if not push_notification_config or not push_notification_config[0]:
             raise ServerError(error=InternalError())
 
         return TaskPushNotificationConfig(
-            taskId=params.id, pushNotificationConfig=push_notification_config
+            taskId=params.id, pushNotificationConfig=push_notification_config[0]
         )
 
     async def on_resubscribe_to_task(
@@ -431,6 +435,51 @@ async def on_resubscribe_to_task(
         async for event in result_aggregator.consume_and_emit(consumer):
             yield event
 
+    async def on_list_task_push_notification_config(
+        self,
+        params: ListTaskPushNotificationConfigParams,
+        context: ServerCallContext | None = None,
+    ) -> list[TaskPushNotificationConfig]:
+        """Default handler for 'tasks/pushNotificationConfig/list'.
+
+        Requires a `PushConfigStore` to be configured.
+        """
+        if not self._push_config_store:
+            raise ServerError(error=UnsupportedOperationError())
+
+        task: Task | None = await self.task_store.get(params.id)
+        if not task:
+            raise ServerError(error=TaskNotFoundError())
+
+        push_notification_config_list = await self._push_config_store.get_info(params.id)
+
+        task_push_notification_config = []
+        if push_notification_config_list:
+            for config in push_notification_config_list:
+                task_push_notification_config.append(TaskPushNotificationConfig(
+                    taskId=params.id, pushNotificationConfig=config
+                ))
+        
+        return task_push_notification_config
+
+    async def on_delete_task_push_notification_config(
+        self,
+        params: DeleteTaskPushNotificationConfigParams,
+        context: ServerCallContext | None = None,
+    ) -> None:
+        """Default handler for 'tasks/pushNotificationConfig/delete'.
+
+        Requires a `PushConfigStore` to be configured.
+        """
+        if not self._push_config_store:
+            raise ServerError(error=UnsupportedOperationError())
+
+        task: Task | None = await self.task_store.get(params.id)
+        if not task:
+            raise ServerError(error=TaskNotFoundError())
+
+        await self._push_config_store.delete_info(params.id, params.pushNotificationConfigId)
+
     def should_add_push_info(self, params: MessageSendParams) -> bool:
         """Determines if push notification info should be set for a task."""
         return bool(

src/a2a/server/request_handlers/jsonrpc_handler.py

@@ -34,6 +34,12 @@
     TaskPushNotificationConfig,
     TaskResubscriptionRequest,
     TaskStatusUpdateEvent,
+    ListTaskPushNotificationConfigRequest,
+    ListTaskPushNotificationConfigResponse,
+    ListTaskPushNotificationConfigSuccessResponse,
+    DeleteTaskPushNotificationConfigRequest,
+    DeleteTaskPushNotificationConfigResponse,
+    DeleteTaskPushNotificationConfigSuccessResponse
 )
 from a2a.utils.errors import ServerError
 from a2a.utils.helpers import validate
@@ -214,7 +220,7 @@ async def on_resubscribe_to_task(
                 )
             )
 
-    async def get_push_notification(
+    async def get_push_notification_config(
         self,
         request: GetTaskPushNotificationConfigRequest,
         context: ServerCallContext | None = None,
@@ -252,7 +258,7 @@ async def get_push_notification(
         lambda self: self.agent_card.capabilities.pushNotifications,
         'Push notifications are not supported by the agent',
     )
-    async def set_push_notification(
+    async def set_push_notification_config(
         self,
         request: SetTaskPushNotificationConfigRequest,
         context: ServerCallContext | None = None,
@@ -325,3 +331,69 @@ async def on_get_task(
                     id=request.id, error=e.error if e.error else InternalError()
                 )
             )
+
+    async def list_push_notification_config(
+        self,
+        request: ListTaskPushNotificationConfigRequest,
+        context: ServerCallContext | None = None,
+    ) -> ListTaskPushNotificationConfigResponse:
+        """Handles the 'tasks/pushNotificationConfig/list' JSON-RPC method.
+
+        Args:
+            request: The incoming `ListTaskPushNotificationConfigRequest` object.
+            context: Context provided by the server.
+
+        Returns:
+            A `ListTaskPushNotificationConfigResponse` object containing the config or a JSON-RPC error.
+        """
+        try:
+            config = (
+                await self.request_handler.on_list_task_push_notification_config(
+                    request.params, context
+                )
+            )
+            return prepare_response_object(
+                request.id,
+                config,
+                (list,),
+                ListTaskPushNotificationConfigSuccessResponse,
+                ListTaskPushNotificationConfigResponse,
+            )
+        except ServerError as e:
+            return ListTaskPushNotificationConfigResponse(
+                root=JSONRPCErrorResponse(
+                    id=request.id, error=e.error if e.error else InternalError()
+                )
+            )
+        
+    async def delete_push_notification_config(
+        self,
+        request: DeleteTaskPushNotificationConfigRequest,
+        context: ServerCallContext | None = None,
+    ) -> DeleteTaskPushNotificationConfigResponse:
+        """Handles the 'tasks/pushNotificationConfig/list' JSON-RPC method.
+
+        Args:
+            request: The incoming `DeleteTaskPushNotificationConfigRequest` object.
+            context: Context provided by the server.
+
+        Returns:
+            A `DeleteTaskPushNotificationConfigResponse` object containing the config or a JSON-RPC error.
+        """
+        try:
+            (
+                await self.request_handler.on_delete_task_push_notification_config(
+                    request.params, context
+                )
+            )
+            return DeleteTaskPushNotificationConfigResponse(
+                root=DeleteTaskPushNotificationConfigSuccessResponse(
+                    id=request.id, result=None
+                )
+            )
+        except ServerError as e:
+            return DeleteTaskPushNotificationConfigResponse(
+                root=JSONRPCErrorResponse(
+                    id=request.id, error=e.error if e.error else InternalError()
+                )
+            )

src/a2a/server/request_handlers/request_handler.py

@@ -12,6 +12,8 @@
     TaskPushNotificationConfig,
     TaskQueryParams,
     UnsupportedOperationError,
+    ListTaskPushNotificationConfigParams,
+    DeleteTaskPushNotificationConfigParams
 )
 from a2a.utils.errors import ServerError
 
@@ -160,3 +162,39 @@ async def on_resubscribe_to_task(
         """
         raise ServerError(error=UnsupportedOperationError())
         yield
+
+    @abstractmethod
+    async def on_list_task_push_notification_config(
+        self,
+        params: ListTaskPushNotificationConfigParams,
+        context: ServerCallContext | None = None,
+    ) -> list[TaskPushNotificationConfig]:
+        """Handles the 'tasks/pushNotificationConfig/list' method.
+
+        Retrieves the current push notification configurations for a task.
+
+        Args:
+            params: Parameters including the task ID.
+            context: Context provided by the server.
+
+        Returns:
+            The `list[TaskPushNotificationConfig]` for the task.
+        """
+
+    @abstractmethod
+    async def on_delete_task_push_notification_config(
+        self,
+        params: DeleteTaskPushNotificationConfigParams,
+        context: ServerCallContext | None = None,
+    ) -> None:
+        """Handles the 'tasks/pushNotificationConfig/delete' method.
+
+        Deletes a push notification configuration associated with a task.
+
+        Args:
+            params: Parameters including the task ID.
+            context: Context provided by the server.
+
+        Returns:
+            None
+        """

src/a2a/server/request_handlers/response_helpers.py

@@ -25,6 +25,10 @@
     TaskArtifactUpdateEvent,
     TaskPushNotificationConfig,
     TaskStatusUpdateEvent,
+    ListTaskPushNotificationConfigResponse,
+    DeleteTaskPushNotificationConfigResponse,
+    ListTaskPushNotificationConfigSuccessResponse,
+    DeleteTaskPushNotificationConfigSuccessResponse
 )
 
 
@@ -36,6 +40,8 @@
     SetTaskPushNotificationConfigResponse,
     GetTaskPushNotificationConfigResponse,
     SendStreamingMessageResponse,
+    ListTaskPushNotificationConfigResponse,
+    DeleteTaskPushNotificationConfigResponse
 )
 """Type variable for RootModel response types."""
 
@@ -48,6 +54,8 @@
     SetTaskPushNotificationConfigSuccessResponse,
     GetTaskPushNotificationConfigSuccessResponse,
     SendStreamingMessageSuccessResponse,
+    ListTaskPushNotificationConfigSuccessResponse,
+    DeleteTaskPushNotificationConfigSuccessResponse
 )
 """Type variable for SuccessResponse types."""
 
@@ -60,6 +68,7 @@
     | TaskPushNotificationConfig
     | A2AError
     | JSONRPCError
+    | list[TaskPushNotificationConfig]
 )
 """Type alias for possible event types produced by handlers."""
 

src/a2a/server/tasks/base_push_notification_sender.py

@@ -6,7 +6,7 @@
     PushNotificationConfigStore,
 )
 from a2a.server.tasks.push_notification_sender import PushNotificationSender
-from a2a.types import Task
+from a2a.types import Task, PushNotificationConfig
 
 
 logger = logging.getLogger(__name__)
@@ -27,11 +27,15 @@ def __init__(self, httpx_client: httpx.AsyncClient, config_store: PushNotificati
 
     async def send_notification(self, task: Task) -> None:
         """Sends a push notification for a task if configuration exists."""
-        push_info = await self._config_store.get_info(task.id)
-        if not push_info:
+        push_configs = await self._config_store.get_info(task.id)
+        if not push_configs:
             return
-        url = push_info.url
+        
+        for push_info in push_configs:
+            await self._dispatch_notification(task, push_info)
 
+    async def _dispatch_notification(self, task: Task, push_info: PushNotificationConfig) -> None:
+        url = push_info.url
         try:
             response = await self._client.post(
                 url, json=task.model_dump(mode='json', exclude_none=True)

src/a2a/server/tasks/inmemory_push_notification_config_store.py

@@ -13,34 +13,49 @@
 class InMemoryPushNotificationConfigStore(PushNotificationConfigStore):
     """In-memory implementation of PushNotificationConfigStore interface.
 
-    Stores push notification configurations in memory and uses an httpx client
-    to send notifications.
+    Stores push notification configurations in memory
     """
     def __init__(self) -> None:
-        """Initializes the InMemoryPushNotifier.
-
-        Args:
-            httpx_client: An async HTTP client instance to send notifications.
-        """
+        """Initializes the InMemoryPushNotificationConfigStore."""
         self.lock = asyncio.Lock()
-        self._push_notification_infos: dict[str, PushNotificationConfig] = {}
+        self._push_notification_infos: dict[str, list[PushNotificationConfig]] = {}
 
     async def set_info(
         self, task_id: str, notification_config: PushNotificationConfig
     ) -> None:
         """Sets or updates the push notification configuration for a task in memory."""
         async with self.lock:
-            self._push_notification_infos[task_id] = notification_config
+            if task_id not in self._push_notification_infos:
+                self._push_notification_infos[task_id] = []
+            
+            if notification_config.id is None:
+                notification_config.id = task_id
+            
+            for config in self._push_notification_infos[task_id]:
+                if config.id == notification_config.id:
+                    self._push_notification_infos[task_id].remove(config)
+                    break
 
-    async def get_info(self, task_id: str) -> PushNotificationConfig | None:
-        """Retrieves the push notification configuration for a task from memory."""
-        async with self.lock:
-            return self._push_notification_infos.get(task_id)
+            self._push_notification_infos[task_id].append(notification_config)
 
 
+    async def get_info(self, task_id: str) -> list[PushNotificationConfig]:
+        """Retrieves the push notification configuration for a task from memory."""
+        async with self.lock:
+            return self._push_notification_infos.get(task_id) or []
 
-    async def delete_info(self, task_id: str) -> None:
+    async def delete_info(self, task_id: str, config_id: str | None = None) -> None:
         """Deletes the push notification configuration for a task from memory."""
         async with self.lock:
+            if config_id is None:
+                config_id = task_id
+
             if task_id in self._push_notification_infos:
-                del self._push_notification_infos[task_id]
+                configurations = self._push_notification_infos[task_id]
+                if not configurations:
+                    return
+                
+                for config in configurations:
+                    if config.id == config_id:
+                        configurations.remove(config)
+                        break