Move payload reduction to default_request_handler

Author: lkawka

src/a2a/server/request_handlers/default_request_handler.py

@@ -131,10 +131,22 @@ async def on_list_tasks(
     ) -> ListTasksResult:
         """Default handler for 'tasks/list'."""
         page = await self.task_store.list(params, context)
+        processed_tasks = []
+        for task in page.tasks:
+            processed_task = task
+            if params.include_artifacts is not True:
+                processed_task = processed_task.model_copy(
+                    update={'artifacts': None}
+                )
+            if params.history_length is not None:
+                processed_task = apply_history_length(
+                    processed_task, params.history_length
+                )
+            processed_tasks.append(processed_task)
         return ListTasksResult(
             next_page_token=page.next_page_token,
             page_size=params.page_size or DEFAULT_LIST_TASKS_PAGE_SIZE,
-            tasks=page.tasks,
+            tasks=processed_tasks,
             total_size=page.total_size,
         )
 

src/a2a/server/tasks/inmemory_task_store.py

@@ -1,8 +1,6 @@
 import asyncio
 import logging
 
-from typing import Any
-
 from a2a.server.context import ServerCallContext
 from a2a.server.tasks.task_store import TaskStore, TasksPage
 from a2a.types import ListTasksParams, Task
@@ -65,22 +63,6 @@ async def list(
                 task for task in tasks if task.status.state == params.status
             ]
 
-        # Reduce payload
-        base_updates: dict[str, Any] = {}
-        if not params.include_artifacts:
-            base_updates = {'artifacts': []}
-        for i in range(len(tasks)):
-            updates = dict(base_updates)
-            history = tasks[i].history
-            if params.history_length is not None and history:
-                limited_history = (
-                    history[-params.history_length :]
-                    if params.history_length > 0
-                    else []
-                )
-                updates['history'] = limited_history
-            tasks[i] = tasks[i].model_copy(update=updates)
-
         # Apply pagination
         total_size = len(tasks)
         page_token = int(params.page_token) if params.page_token else 0

tests/client/test_grpc_client.py

@@ -10,6 +10,7 @@
     AgentCard,
     Artifact,
     GetTaskPushNotificationConfigParams,
+    ListTasksParams,
     Message,
     MessageSendParams,
     Part,
@@ -25,7 +26,6 @@
     TaskStatus,
     TaskStatusUpdateEvent,
     TextPart,
-    ListTasksParams,
 )
 from a2a.utils import get_text_parts, proto_utils
 from a2a.utils.errors import ServerError

tests/client/test_jsonrpc_client.py

@@ -22,6 +22,8 @@
     AgentCard,
     AgentSkill,
     InvalidParamsError,
+    ListTasksParams,
+    ListTasksResult,
     Message,
     MessageSendParams,
     PushNotificationConfig,
@@ -31,8 +33,6 @@
     TaskIdParams,
     TaskPushNotificationConfig,
     TaskQueryParams,
-    ListTasksParams,
-    ListTasksResult,
 )
 from a2a.utils import AGENT_CARD_WELL_KNOWN_PATH
 

tests/server/request_handlers/test_default_request_handler.py

@@ -21,7 +21,6 @@
 from a2a.server.context import ServerCallContext
 from a2a.server.events import EventQueue, InMemoryQueueManager, QueueManager
 from a2a.server.request_handlers import DefaultRequestHandler
-from a2a.server.tasks.task_store import TasksPage
 from a2a.server.tasks import (
     InMemoryPushNotificationConfigStore,
     InMemoryTaskStore,
@@ -31,14 +30,15 @@
     TaskStore,
     TaskUpdater,
 )
+from a2a.server.tasks.task_store import TasksPage
 from a2a.types import (
+    Artifact,
     DeleteTaskPushNotificationConfigParams,
     GetTaskPushNotificationConfigParams,
     InternalError,
     InvalidParamsError,
     ListTaskPushNotificationConfigParams,
     ListTasksParams,
-    ListTasksResult,
     Message,
     MessageSendConfiguration,
     MessageSendParams,
@@ -56,9 +56,7 @@
     TextPart,
     UnsupportedOperationError,
 )
-from a2a.utils import (
-    new_task,
-)
+from a2a.utils import new_agent_text_message, new_task
 
 
 class DummyAgentExecutor(AgentExecutor):
@@ -155,15 +153,25 @@ async def test_on_list_tasks_success():
     mock_page = MagicMock(spec=TasksPage)
     mock_page.tasks = [
         create_sample_task(task_id='task1'),
-        create_sample_task(task_id='task2'),
+        create_sample_task(task_id='task2').model_copy(
+            update={
+                'artifacts': [
+                    Artifact(
+                        artifact_id='artifact1',
+                        parts=[Part(root=TextPart(text='Hello world!'))],
+                        name='conversion_result',
+                    )
+                ]
+            }
+        ),
     ]
     mock_page.next_page_token = '123'
     mock_page.total_size = 2
     mock_task_store.list.return_value = mock_page
     request_handler = DefaultRequestHandler(
         agent_executor=DummyAgentExecutor(), task_store=mock_task_store
     )
-    params = ListTasksParams(page_size=10)
+    params = ListTasksParams(include_artifacts=True, page_size=10)
     context = create_server_call_context()
 
     result = await request_handler.on_list_tasks(params, context)
@@ -175,6 +183,68 @@ async def test_on_list_tasks_success():
     assert result.page_size == params.page_size
 
 
+@pytest.mark.asyncio
+async def test_on_list_tasks_excludes_artifacts():
+    """Test on_list_tasks excludes artifacts from returned tasks."""
+    mock_task_store = AsyncMock(spec=TaskStore)
+    mock_page = MagicMock(spec=TasksPage)
+    mock_page.tasks = [
+        create_sample_task(task_id='task1'),
+        create_sample_task(task_id='task2').model_copy(
+            update={
+                'artifacts': [
+                    Artifact(
+                        artifact_id='artifact1',
+                        parts=[Part(root=TextPart(text='Hello world!'))],
+                        name='conversion_result',
+                    )
+                ]
+            }
+        ),
+    ]
+    mock_page.next_page_token = '123'
+    mock_page.total_size = 2
+    mock_task_store.list.return_value = mock_page
+    request_handler = DefaultRequestHandler(
+        agent_executor=DummyAgentExecutor(), task_store=mock_task_store
+    )
+    params = ListTasksParams(include_artifacts=False, page_size=10)
+    context = create_server_call_context()
+
+    result = await request_handler.on_list_tasks(params, context)
+
+    assert result.tasks[1].artifacts == None
+
+
+@pytest.mark.asyncio
+async def test_on_list_tasks_applies_history_length():
+    """Test on_list_tasks applies history length filter."""
+    mock_task_store = AsyncMock(spec=TaskStore)
+    mock_page = MagicMock(spec=TasksPage)
+    history = [
+        new_agent_text_message('Hello 1!'),
+        new_agent_text_message('Hello 2!'),
+    ]
+    mock_page.tasks = [
+        create_sample_task(task_id='task1'),
+        create_sample_task(task_id='task2').model_copy(
+            update={'history': history}
+        ),
+    ]
+    mock_page.next_page_token = '123'
+    mock_page.total_size = 2
+    mock_task_store.list.return_value = mock_page
+    request_handler = DefaultRequestHandler(
+        agent_executor=DummyAgentExecutor(), task_store=mock_task_store
+    )
+    params = ListTasksParams(history_length=1, page_size=10)
+    context = create_server_call_context()
+
+    result = await request_handler.on_list_tasks(params, context)
+
+    assert result.tasks[1].history == [history[1]]
+
+
 @pytest.mark.asyncio
 async def test_on_cancel_task_task_not_found():
     """Test on_cancel_task when the task is not found."""

tests/server/request_handlers/test_jsonrpc_handler.py

@@ -36,7 +36,6 @@
     GetAuthenticatedExtendedCardRequest,
     GetAuthenticatedExtendedCardResponse,
     GetAuthenticatedExtendedCardSuccessResponse,
-    ListTasksResult,
     GetTaskPushNotificationConfigParams,
     GetTaskPushNotificationConfigRequest,
     GetTaskPushNotificationConfigResponse,
@@ -51,7 +50,7 @@
     ListTaskPushNotificationConfigSuccessResponse,
     ListTasksParams,
     ListTasksRequest,
-    ListTasksResponse,
+    ListTasksResult,
     ListTasksSuccessResponse,
     Message,
     MessageSendConfiguration,

tests/server/tasks/test_database_task_store.py

@@ -19,14 +19,14 @@
 from a2a.server.tasks.database_task_store import DatabaseTaskStore
 from a2a.types import (
     Artifact,
+    ListTasksParams,
     Message,
     Part,
     Role,
     Task,
     TaskState,
     TaskStatus,
     TextPart,
-    ListTasksParams,
 )
 
 

tests/server/tasks/test_inmemory_task_store.py

@@ -3,7 +3,7 @@
 import pytest
 
 from a2a.server.tasks import InMemoryTaskStore
-from a2a.types import Task, ListTasksParams, TaskState, TaskStatus
+from a2a.types import ListTasksParams, Task, TaskState, TaskStatus
 
 
 MINIMAL_TASK: dict[str, Any] = {

tests/utils/test_proto_utils.py

@@ -2,11 +2,12 @@
 
 import pytest
 
+from google.protobuf.timestamp_pb2 import Timestamp
+
 from a2a import types
 from a2a.grpc import a2a_pb2
 from a2a.utils import proto_utils
 from a2a.utils.errors import ServerError
-from google.protobuf.timestamp_pb2 import Timestamp
 
 
 # --- Test Data ---