feat: add GetExtendedAgentCardRequest as input parameter to GetExtendedAgentCard method (#767)

[Spec](https://a2a-protocol.org/latest/specification/#103-service-definition)
defines `rpc GetExtendedAgentCard(GetExtendedAgentCardRequest) returns
(AgentCard)`. Currently `GetExtendedAgentCard` does not take
`GetExtendedAgentCardRequest` as input parameter.

Fixes #766 🦕

Author: sokoliva

src/a2a/client/base_client.py

@@ -16,6 +16,7 @@
     CancelTaskRequest,
     CreateTaskPushNotificationConfigRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -311,6 +312,7 @@ async def subscribe(
 
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,
@@ -322,6 +324,7 @@ async def get_extended_agent_card(
         client's internal state with the new card.
 
         Args:
+            request: The `GetExtendedAgentCardRequest` object specifying the request.
             context: The client call context.
             extensions: List of extensions to be activated.
             signature_verifier: A callable used to verify the agent card's signatures.
@@ -330,6 +333,7 @@ async def get_extended_agent_card(
             The `AgentCard` for the agent.
         """
         card = await self._transport.get_extended_agent_card(
+            request,
             context=context,
             extensions=extensions,
             signature_verifier=signature_verifier,

src/a2a/client/client.py

@@ -17,6 +17,7 @@
     CancelTaskRequest,
     CreateTaskPushNotificationConfigRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -231,6 +232,7 @@ async def subscribe(
     @abstractmethod
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,

src/a2a/client/transports/base.py

@@ -10,6 +10,7 @@
     CancelTaskRequest,
     CreateTaskPushNotificationConfigRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -148,6 +149,7 @@ async def subscribe(
     @abstractmethod
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,

src/a2a/client/transports/grpc.py

@@ -23,12 +23,13 @@
 from a2a.client.optionals import Channel
 from a2a.client.transports.base import ClientTransport
 from a2a.extensions.common import HTTP_EXTENSION_HEADER
-from a2a.types import a2a_pb2, a2a_pb2_grpc
+from a2a.types import a2a_pb2_grpc
 from a2a.types.a2a_pb2 import (
     AgentCard,
     CancelTaskRequest,
     CreateTaskPushNotificationConfigRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -276,14 +277,15 @@ async def delete_task_push_notification_config(
     @_handle_grpc_exception
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,
         signature_verifier: Callable[[AgentCard], None] | None = None,
     ) -> AgentCard:
         """Retrieves the agent's card."""
         card = await self.stub.GetExtendedAgentCard(
-            a2a_pb2.GetExtendedAgentCardRequest(),
+            request,
             metadata=self._get_grpc_metadata(extensions),
         )
 

src/a2a/client/transports/jsonrpc.py

@@ -378,6 +378,7 @@ async def subscribe(
 
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,
@@ -394,7 +395,6 @@ async def get_extended_agent_card(
         if not card.capabilities.extended_agent_card:
             return card
 
-        request = GetExtendedAgentCardRequest()
         rpc_request = JSONRPC20Request(
             method='GetExtendedAgentCard',
             params=json_format.MessageToDict(request),

src/a2a/client/transports/rest.py

@@ -22,6 +22,7 @@
     CancelTaskRequest,
     CreateTaskPushNotificationConfigRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -324,6 +325,7 @@ async def subscribe(
 
     async def get_extended_agent_card(
         self,
+        request: GetExtendedAgentCardRequest,
         *,
         context: ClientCallContext | None = None,
         extensions: list[str] | None = None,
@@ -340,7 +342,7 @@ async def get_extended_agent_card(
         if not card.capabilities.extended_agent_card:
             return card
         _, modified_kwargs = await self._apply_interceptors(
-            {},
+            MessageToDict(request, preserving_proto_field_name=True),
             modified_kwargs,
             context,
         )

tests/client/transports/test_jsonrpc_client.py

@@ -19,6 +19,7 @@
     AgentInterface,
     CancelTaskRequest,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     ListTaskPushNotificationConfigsRequest,
@@ -647,6 +648,7 @@ async def test_get_card_with_extended_card_support_with_extensions(
         extended_card.CopyFrom(agent_card)
         extended_card.name = 'Extended'
 
+        request = GetExtendedAgentCardRequest()
         rpc_response = {
             'id': '123',
             'jsonrpc': '2.0',
@@ -656,7 +658,7 @@ async def test_get_card_with_extended_card_support_with_extensions(
             client, '_send_request', new_callable=AsyncMock
         ) as mock_send_request:
             mock_send_request.return_value = rpc_response
-            await client.get_extended_agent_card(extensions=extensions)
+            await client.get_extended_agent_card(request, extensions=extensions)
 
         mock_send_request.assert_called_once()
         _, mock_kwargs = mock_send_request.call_args[0]

tests/client/transports/test_rest_client.py

@@ -16,6 +16,7 @@
     AgentCard,
     AgentInterface,
     DeleteTaskPushNotificationConfigRequest,
+    GetExtendedAgentCardRequest,
     ListTaskPushNotificationConfigsRequest,
     SendMessageRequest,
 )
@@ -299,13 +300,14 @@ async def test_get_card_with_extended_card_support_with_extensions(
         )  # Extended card same for mock
         mock_httpx_client.send.return_value = mock_response
 
+        request = GetExtendedAgentCardRequest()
         with patch.object(
             client, '_send_get_request', new_callable=AsyncMock
         ) as mock_send_get_request:
             mock_send_get_request.return_value = json_format.MessageToDict(
                 agent_card
             )
-            await client.get_extended_agent_card(extensions=extensions)
+            await client.get_extended_agent_card(request, extensions=extensions)
 
         mock_send_get_request.assert_called_once()
         _, _, mock_kwargs = mock_send_get_request.call_args[0]

tests/integration/test_client_server_integration.py

@@ -30,6 +30,7 @@
     AgentCard,
     AgentInterface,
     CancelTaskRequest,
+    GetExtendedAgentCardRequest,
     GetTaskPushNotificationConfigRequest,
     GetTaskRequest,
     Message,
@@ -950,7 +951,9 @@ async def test_http_transport_get_authenticated_card(
         agent_card=agent_card,
         url=agent_card.supported_interfaces[0].url,
     )
-    result = await transport.get_extended_agent_card()
+    result = await transport.get_extended_agent_card(
+        GetExtendedAgentCardRequest()
+    )
     assert result.name == extended_agent_card.name
     assert transport.agent_card is not None
     assert transport.agent_card.name == extended_agent_card.name
@@ -976,7 +979,9 @@ def channel_factory(address: str) -> Channel:
     # The transport starts with a minimal card, get_extended_agent_card() fetches the full one
     assert transport.agent_card is not None
     transport.agent_card.capabilities.extended_agent_card = True
-    result = await transport.get_extended_agent_card()
+    result = await transport.get_extended_agent_card(
+        GetExtendedAgentCardRequest()
+    )
 
     assert result.name == agent_card.name
     assert transport.agent_card.name == agent_card.name
@@ -1160,7 +1165,7 @@ async def test_json_transport_get_signed_extended_card(
         create_key_provider(public_key), ['HS384', 'ES256']
     )
     result = await transport.get_extended_agent_card(
-        signature_verifier=signature_verifier
+        GetExtendedAgentCardRequest(), signature_verifier=signature_verifier
     )
     assert result.name == extended_agent_card.name
     assert result.signatures is not None
@@ -1239,7 +1244,7 @@ async def test_json_transport_get_signed_base_and_extended_cards(
 
     # 3. Fetch extended card via transport
     result = await transport.get_extended_agent_card(
-        signature_verifier=signature_verifier
+        GetExtendedAgentCardRequest(), signature_verifier=signature_verifier
     )
     assert result.name == extended_agent_card.name
     assert len(result.signatures) == 1
@@ -1316,7 +1321,7 @@ async def test_rest_transport_get_signed_card(
 
     # 3. Fetch extended card
     result = await transport.get_extended_agent_card(
-        signature_verifier=signature_verifier
+        GetExtendedAgentCardRequest(), signature_verifier=signature_verifier
     )
     assert result.name == extended_agent_card.name
     assert result.signatures is not None
@@ -1378,7 +1383,7 @@ def channel_factory(address: str) -> Channel:
             create_key_provider(public_key), ['HS384', 'ES256', 'RS256']
         )
         result = await transport.get_extended_agent_card(
-            signature_verifier=signature_verifier
+            GetExtendedAgentCardRequest(), signature_verifier=signature_verifier
         )
         assert result.signatures is not None
         assert len(result.signatures) == 1