bring back aget_card

Author: sokoliva

src/a2a/server/request_handlers/default_request_handler.py

@@ -144,6 +144,12 @@ def __init__(  # noqa: PLR0913
         # asyncio tasks and to surface unexpected exceptions.
         self._background_tasks = set()
 
+    # TODO: Remove this property when we implement GetExtendedCard method in compat request handler.
+    @property
+    def agent_card(self) -> AgentCard:
+        """The core agent card to serve logic against."""
+        return self._agent_card
+
     @validate_request_params
     async def on_get_task(
         self,
@@ -684,11 +690,6 @@ async def on_delete_task_push_notification_config(
         lambda self: self._agent_card.capabilities.extended_agent_card,
         error_message='The agent does not support authenticated extended cards',
     )
-    @validate(
-        lambda self: self.extended_agent_card,
-        error_message='The agent does not have an extended agent card configured',
-        error_type=ExtendedAgentCardNotConfiguredError,
-    )
     async def on_get_extended_agent_card(
         self,
         params: GetExtendedAgentCardRequest,
@@ -698,6 +699,9 @@ async def on_get_extended_agent_card(
 
         Requires `capabilities.extended_agent_card` to be true.
         """
+        if not self.extended_agent_card:
+            raise ExtendedAgentCardNotConfiguredError
+
         extended_card = self.extended_agent_card
 
         if self.extended_card_modifier:

src/a2a/server/request_handlers/request_handler.py

@@ -36,6 +36,12 @@ class RequestHandler(ABC):
     provide to handle incoming A2A requests from any transport (gRPC, REST, JSON-RPC).
     """
 
+    # TODO: Remove this property when we implement GetExtendedCard method in compat request handler.
+    @property
+    @abstractmethod
+    def agent_card(self) -> AgentCard:
+        """The core agent card to serve logic against."""
+
     @abstractmethod
     async def on_get_task(
         self,

src/a2a/server/routes/jsonrpc_dispatcher.py

@@ -220,7 +220,7 @@ def __init__(
 
         if self.enable_v0_3_compat:
             self._v03_adapter = JSONRPC03Adapter(
-                agent_card=getattr(request_handler, '_agent_card', None),
+                agent_card=request_handler.agent_card,
                 http_handler=request_handler,
                 extended_agent_card=getattr(
                     request_handler, '_extended_agent_card', None

src/a2a/server/routes/rest_routes.py

@@ -70,7 +70,7 @@ def create_rest_routes(
     routes: list[BaseRoute] = []
     if enable_v0_3_compat:
         v03_adapter = REST03Adapter(
-            agent_card=getattr(request_handler, '_agent_card', None),
+            agent_card=request_handler.agent_card,
             http_handler=request_handler,
             extended_agent_card=getattr(
                 request_handler, '_extended_agent_card', None

tests/server/routes/test_jsonrpc_dispatcher.py

@@ -254,6 +254,8 @@ def test_v0_3_compat_flag_routes_to_adapter(self, mock_handler):
         mock_agent_card.capabilities = MagicMock()
         mock_agent_card.capabilities.streaming = False
 
+        mock_handler._agent_card = mock_agent_card
+
         from starlette.applications import Starlette
 
         jsonrpc_routes = create_jsonrpc_routes(