fix: allign error code with the latest spec

Source: https://a2a-protocol.org/latest/specification/#54-error-code-mappings.

Added roundtrip tests to `test_client_server_integration.py`.

Author: ishymko

src/a2a/server/request_handlers/grpc_handler.py

@@ -90,11 +90,14 @@ def build(self, context: grpc.aio.ServicerContext) -> ServerCallContext:
     types.InvalidParamsError: grpc.StatusCode.INVALID_ARGUMENT,
     types.InternalError: grpc.StatusCode.INTERNAL,
     types.TaskNotFoundError: grpc.StatusCode.NOT_FOUND,
-    types.TaskNotCancelableError: grpc.StatusCode.UNIMPLEMENTED,
+    types.TaskNotCancelableError: grpc.StatusCode.FAILED_PRECONDITION,
     types.PushNotificationNotSupportedError: grpc.StatusCode.UNIMPLEMENTED,
     types.UnsupportedOperationError: grpc.StatusCode.UNIMPLEMENTED,
-    types.ContentTypeNotSupportedError: grpc.StatusCode.UNIMPLEMENTED,
+    types.ContentTypeNotSupportedError: grpc.StatusCode.INVALID_ARGUMENT,
     types.InvalidAgentResponseError: grpc.StatusCode.INTERNAL,
+    types.AuthenticatedExtendedCardNotConfiguredError: grpc.StatusCode.FAILED_PRECONDITION,
+    types.ExtensionSupportRequiredError: grpc.StatusCode.FAILED_PRECONDITION,
+    types.VersionNotSupportedError: grpc.StatusCode.UNIMPLEMENTED,
 }
 
 

src/a2a/server/request_handlers/jsonrpc_handler.py

@@ -37,6 +37,7 @@
     A2AError,
     AuthenticatedExtendedCardNotConfiguredError,
     ContentTypeNotSupportedError,
+    ExtensionSupportRequiredError,
     InternalError,
     InvalidAgentResponseError,
     InvalidParamsError,
@@ -46,6 +47,7 @@
     TaskNotCancelableError,
     TaskNotFoundError,
     UnsupportedOperationError,
+    VersionNotSupportedError,
 )
 from a2a.utils.helpers import maybe_await, validate
 from a2a.utils.telemetry import SpanKind, trace_class
@@ -66,6 +68,8 @@
     InvalidParamsError: JSONRPCError,
     InvalidRequestError: JSONRPCError,
     MethodNotFoundError: JSONRPCError,
+    ExtensionSupportRequiredError: JSONRPCError,
+    VersionNotSupportedError: JSONRPCError,
 }
 
 

src/a2a/server/request_handlers/response_helpers.py

@@ -31,6 +31,7 @@
     A2AError,
     AuthenticatedExtendedCardNotConfiguredError,
     ContentTypeNotSupportedError,
+    ExtensionSupportRequiredError,
     InternalError,
     InvalidAgentResponseError,
     InvalidParamsError,
@@ -40,6 +41,7 @@
     TaskNotCancelableError,
     TaskNotFoundError,
     UnsupportedOperationError,
+    VersionNotSupportedError,
 )
 
 
@@ -55,6 +57,8 @@
     InvalidRequestError: JSONRPCError,
     MethodNotFoundError: JSONRPCError,
     InternalError: JSONRPCInternalError,
+    ExtensionSupportRequiredError: JSONRPCError,
+    VersionNotSupportedError: JSONRPCError,
 }
 
 

src/a2a/types/__init__.py

@@ -54,6 +54,7 @@
 from a2a.utils.errors import (
     AuthenticatedExtendedCardNotConfiguredError,
     ContentTypeNotSupportedError,
+    ExtensionSupportRequiredError,
     InternalError,
     InvalidAgentResponseError,
     InvalidParamsError,
@@ -63,6 +64,7 @@
     TaskNotCancelableError,
     TaskNotFoundError,
     UnsupportedOperationError,
+    VersionNotSupportedError,
 )
 
 
@@ -99,6 +101,7 @@
     'ContentTypeNotSupportedError',
     'DeleteTaskPushNotificationConfigRequest',
     'DeviceCodeOAuthFlow',
+    'ExtensionSupportRequiredError',
     'GetExtendedAgentCardRequest',
     'GetTaskPushNotificationConfigRequest',
     'GetTaskRequest',
@@ -139,4 +142,5 @@
     'TaskStatus',
     'TaskStatusUpdateEvent',
     'UnsupportedOperationError',
+    'VersionNotSupportedError',
 ]

src/a2a/utils/error_handlers.py

@@ -28,6 +28,7 @@
     A2AError,
     AuthenticatedExtendedCardNotConfiguredError,
     ContentTypeNotSupportedError,
+    ExtensionSupportRequiredError,
     InternalError,
     InvalidAgentResponseError,
     InvalidParamsError,
@@ -37,6 +38,7 @@
     TaskNotCancelableError,
     TaskNotFoundError,
     UnsupportedOperationError,
+    VersionNotSupportedError,
 )
 
 
@@ -74,6 +76,8 @@
     ContentTypeNotSupportedError: 415,
     InvalidAgentResponseError: 502,
     AuthenticatedExtendedCardNotConfiguredError: 404,
+    ExtensionSupportRequiredError: 400,
+    VersionNotSupportedError: 400,
 }
 
 

src/a2a/utils/errors.py

@@ -123,6 +123,8 @@ class VersionNotSupportedError(A2AError):
     ContentTypeNotSupportedError: -32005,
     InvalidAgentResponseError: -32006,
     AuthenticatedExtendedCardNotConfiguredError: -32007,
+    ExtensionSupportRequiredError: -32008,
+    VersionNotSupportedError: -32009,
     InvalidParamsError: -32602,
     InvalidRequestError: -32600,
     MethodNotFoundError: -32601,

tests/integration/test_client_server_integration.py

@@ -50,7 +50,24 @@
     TaskStatus,
     TaskStatusUpdateEvent,
 )
-from a2a.utils.constants import TransportProtocol
+from a2a.utils.constants import (
+    TransportProtocol,
+)
+from a2a.utils.errors import (
+    AuthenticatedExtendedCardNotConfiguredError,
+    ContentTypeNotSupportedError,
+    ExtensionSupportRequiredError,
+    InternalError,
+    InvalidAgentResponseError,
+    InvalidParamsError,
+    InvalidRequestError,
+    MethodNotFoundError,
+    PushNotificationNotSupportedError,
+    TaskNotCancelableError,
+    TaskNotFoundError,
+    UnsupportedOperationError,
+    VersionNotSupportedError,
+)
 from a2a.utils.signing import (
     create_agent_card_signer,
     create_signature_verifier,
@@ -788,6 +805,43 @@ async def test_client_get_signed_base_and_extended_cards(
     await client.close()
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    'error_cls',
+    [
+        TaskNotFoundError,
+        TaskNotCancelableError,
+        PushNotificationNotSupportedError,
+        UnsupportedOperationError,
+        ContentTypeNotSupportedError,
+        InvalidAgentResponseError,
+        AuthenticatedExtendedCardNotConfiguredError,
+        ExtensionSupportRequiredError,
+        VersionNotSupportedError,
+    ],
+)
+async def test_client_handles_a2a_errors(transport_setups, error_cls) -> None:
+    """Integration test to verify error propagation from handler to client."""
+    client = transport_setups.client
+    handler = transport_setups.handler
+
+    # Mock the handler to raise the error
+    handler.on_get_task.side_effect = error_cls('Test error message')
+
+    params = GetTaskRequest(id='some-id')
+
+    # We expect the client to raise the same error_cls.
+    with pytest.raises(error_cls) as exc_info:
+        await client.get_task(request=params)
+
+    assert 'Test error message' in str(exc_info.value)
+
+    # Reset side_effect for other tests
+    handler.on_get_task.side_effect = None
+
+    await client.close()
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     'request_kwargs, expected_error_code',

tests/server/request_handlers/test_grpc_handler.py

@@ -143,25 +143,6 @@ async def test_get_task_not_found(
     )
 
 
-@pytest.mark.asyncio
-async def test_cancel_task_server_error(
-    grpc_handler: GrpcHandler,
-    mock_request_handler: AsyncMock,
-    mock_grpc_context: AsyncMock,
-) -> None:
-    """Test CancelTask call when handler raises A2AError."""
-    request_proto = a2a_pb2.CancelTaskRequest(id='task-1')
-    error = types.TaskNotCancelableError()
-    mock_request_handler.on_cancel_task.side_effect = error
-
-    await grpc_handler.CancelTask(request_proto, mock_grpc_context)
-
-    mock_grpc_context.abort.assert_awaited_once_with(
-        grpc.StatusCode.UNIMPLEMENTED,
-        'Task cannot be canceled',
-    )
-
-
 @pytest.mark.asyncio
 async def test_send_streaming_message(
     grpc_handler: GrpcHandler,
@@ -340,7 +321,7 @@ async def test_list_tasks_success(
         ),
         (
             types.TaskNotCancelableError(),
-            grpc.StatusCode.UNIMPLEMENTED,
+            grpc.StatusCode.FAILED_PRECONDITION,
             'TaskNotCancelableError',
         ),
         (
@@ -355,7 +336,7 @@ async def test_list_tasks_success(
         ),
         (
             types.ContentTypeNotSupportedError(),
-            grpc.StatusCode.UNIMPLEMENTED,
+            grpc.StatusCode.INVALID_ARGUMENT,
             'ContentTypeNotSupportedError',
         ),
         (