feat!: Add method for fetching extended card

src/a2a/types.py

@@ -172,6 +172,26 @@ class AgentSkill(A2ABaseModel):
     """
 
 
+class AuthenticatedExtendedCardNotConfiguredError(A2ABaseModel):
+    """
+    An A2A-specific error indicating that the agent does not have an Authenticated Extended Card configured
+    """
+
+    code: Literal[-32007] = -32007
+    """
+    The error code for when an authenticated extended card is not configured.
+    """
+    data: Any | None = None
+    """
+    A primitive or structured value containing additional information about the error.
+    This may be omitted.
+    """
+    message: str | None = 'Authenticated Extended Card is not configured'
+    """
+    The error message.
+    """
+
+
 class AuthorizationCodeOAuthFlow(A2ABaseModel):
     """
     Defines configuration details for the OAuth 2.0 Authorization Code flow.
@@ -375,6 +395,27 @@ class FileWithUri(A2ABaseModel):
     """
 
 
+class GetAuthenticatedExtendedCardRequest(A2ABaseModel):
+    """
+    Represents a JSON-RPC request for the `agent/getAuthenticatedExtendedCard` method.
+    """
+
+    id: str | int
+    """
+    The identifier for this request.
+    """
+    jsonrpc: Literal['2.0'] = '2.0'
+    """
+    The version of the JSON-RPC protocol. MUST be exactly "2.0".
+    """
+    method: Literal['agent/getAuthenticatedExtendedCard'] = (
+        'agent/getAuthenticatedExtendedCard'
+    )
+    """
+    The method name. Must be 'agent/getAuthenticatedExtendedCard'.
+    """
+
+
 class GetTaskPushNotificationConfigParams(A2ABaseModel):
     """
     Defines parameters for fetching a specific push notification configuration for a task.
@@ -999,6 +1040,7 @@ class A2AError(
         | UnsupportedOperationError
         | ContentTypeNotSupportedError
         | InvalidAgentResponseError
+        | AuthenticatedExtendedCardNotConfiguredError
     ]
 ):
     root: (
@@ -1013,6 +1055,7 @@ class A2AError(
         | UnsupportedOperationError
         | ContentTypeNotSupportedError
         | InvalidAgentResponseError
+        | AuthenticatedExtendedCardNotConfiguredError
     )
     """
     A discriminated union of all standard JSON-RPC and A2A-specific error types.
@@ -1170,6 +1213,7 @@ class JSONRPCErrorResponse(A2ABaseModel):
         | UnsupportedOperationError
         | ContentTypeNotSupportedError
         | InvalidAgentResponseError
+        | AuthenticatedExtendedCardNotConfiguredError
     )
     """
     An object describing the error that occurred.
@@ -1625,6 +1669,7 @@ class A2ARequest(
         | TaskResubscriptionRequest
         | ListTaskPushNotificationConfigRequest
         | DeleteTaskPushNotificationConfigRequest
+        | GetAuthenticatedExtendedCardRequest
     ]
 ):
     root: (
@@ -1637,6 +1682,7 @@ class A2ARequest(
         | TaskResubscriptionRequest
         | ListTaskPushNotificationConfigRequest
         | DeleteTaskPushNotificationConfigRequest
+        | GetAuthenticatedExtendedCardRequest
     )
     """
     A discriminated union representing all possible JSON-RPC 2.0 requests supported by the A2A specification.
@@ -1750,6 +1796,25 @@ class AgentCard(A2ABaseModel):
     """
 
 
+class GetAuthenticatedExtendedCardSuccessResponse(A2ABaseModel):
+    """
+    Represents a successful JSON-RPC response for the `agent/getAuthenticatedExtendedCard` method.
+    """
+
+    id: str | int | None = None
+    """
+    The identifier established by the client.
+    """
+    jsonrpc: Literal['2.0'] = '2.0'
+    """
+    The version of the JSON-RPC protocol. MUST be exactly "2.0".
+    """
+    result: AgentCard
+    """
+    The result is an Agent Card object.
+    """
+
+
 class Task(A2ABaseModel):
     """
     Represents a single, stateful operation or conversation between a client and an agent.
@@ -1769,7 +1834,7 @@ class Task(A2ABaseModel):
     """
     id: str
     """
-    A unique identifier for the task, generated by the client for a new task or provided by the agent.
+    A unique identifier for the task, generated by the server for a new task.
     """
     kind: Literal['task'] = 'task'
     """
@@ -1804,6 +1869,17 @@ class CancelTaskSuccessResponse(A2ABaseModel):
     """
 
 
+class GetAuthenticatedExtendedCardResponse(
+    RootModel[
+        JSONRPCErrorResponse | GetAuthenticatedExtendedCardSuccessResponse
+    ]
+):
+    root: JSONRPCErrorResponse | GetAuthenticatedExtendedCardSuccessResponse
+    """
+    Represents a JSON-RPC response for the `agent/getAuthenticatedExtendedCard` method.
+    """
+
+
 class GetTaskSuccessResponse(A2ABaseModel):
     """
     Represents a successful JSON-RPC response for the `tasks/get` method.
@@ -1889,6 +1965,7 @@ class JSONRPCResponse(
         | GetTaskPushNotificationConfigSuccessResponse
         | ListTaskPushNotificationConfigSuccessResponse
         | DeleteTaskPushNotificationConfigSuccessResponse
+        | GetAuthenticatedExtendedCardSuccessResponse
     ]
 ):
     root: (
@@ -1901,6 +1978,7 @@ class JSONRPCResponse(
         | GetTaskPushNotificationConfigSuccessResponse
         | ListTaskPushNotificationConfigSuccessResponse
         | DeleteTaskPushNotificationConfigSuccessResponse
+        | GetAuthenticatedExtendedCardSuccessResponse
     )
     """
     A discriminated union representing all possible JSON-RPC 2.0 responses

tests/server/test_integration.py

@@ -836,7 +836,8 @@ def test_invalid_request_structure(client: TestClient):
         '/',
         json={
             # Missing required fields
-            'id': '123'
+            'id': '123',
+            'method': 'foo/bar',
         },
     )
     assert response.status_code == 200

tests/test_types.py

@@ -24,6 +24,9 @@
     FileWithUri,
     GetTaskPushNotificationConfigParams,
     GetTaskPushNotificationConfigRequest,
+    GetAuthenticatedExtendedCardRequest,
+    GetAuthenticatedExtendedCardResponse,
+    GetAuthenticatedExtendedCardSuccessResponse,
     GetTaskPushNotificationConfigResponse,
     GetTaskPushNotificationConfigSuccessResponse,
     GetTaskRequest,
@@ -968,6 +971,21 @@ def test_a2a_request_root_model() -> None:
     assert isinstance(a2a_req_task_resubscribe_req.root.params, TaskIdParams)
     assert a2a_req_task_resubscribe_req.root.method == 'tasks/resubscribe'
 
+    # GetAuthenticatedExtendedCardRequest
+    get_auth_card_req_data: dict[str, Any] = {
+        'jsonrpc': '2.0',
+        'method': 'agent/getAuthenticatedExtendedCard',
+        'id': 2,
+    }
+    a2a_req_get_auth_card = A2ARequest.model_validate(get_auth_card_req_data)
+    assert isinstance(
+        a2a_req_get_auth_card.root, GetAuthenticatedExtendedCardRequest
+    )
+    assert (
+        a2a_req_get_auth_card.root.method
+        == 'agent/getAuthenticatedExtendedCard'
+    )
+
     # Invalid method case
     invalid_req_data: dict[str, Any] = {
         'jsonrpc': '2.0',
@@ -1055,6 +1073,14 @@ def test_a2a_request_root_model_id_validation() -> None:
     with pytest.raises(ValidationError):
         A2ARequest.model_validate(task_resubscribe_req_data)
 
+    # GetAuthenticatedExtendedCardRequest
+    get_auth_card_req_data: dict[str, Any] = {
+        'jsonrpc': '2.0',
+        'method': 'agent/getAuthenticatedExtendedCard',
+    }
+    with pytest.raises(ValidationError):
+        A2ARequest.model_validate(get_auth_card_req_data)  # missing id
+
 
 def test_content_type_not_supported_error():
     # Test ContentTypeNotSupportedError
@@ -1544,11 +1570,11 @@ def test_camelCase() -> None:
         description='Just a hello world agent',
         url='http://localhost:9999/',
         version='1.0.0',
-        defaultInputModes=['text'],
-        defaultOutputModes=['text'],
+        defaultInputModes=['text'],  # type: ignore
+        defaultOutputModes=['text'],  # type: ignore
         capabilities=AgentCapabilities(streaming=True),
         skills=[skill],
-        supportsAuthenticatedExtendedCard=True,
+        supportsAuthenticatedExtendedCard=True,  # type: ignore
     )
 
     # Test setting an attribute via camelCase alias
@@ -1568,3 +1594,56 @@ def test_camelCase() -> None:
     assert agent_card.supports_authenticated_extended_card is False
     assert default_input_modes == ['text']
     assert agent_card.default_input_modes == ['text']
+
+
+def test_get_authenticated_extended_card_request() -> None:
+    req_data: dict[str, Any] = {
+        'jsonrpc': '2.0',
+        'method': 'agent/getAuthenticatedExtendedCard',
+        'id': 5,
+    }
+    req = GetAuthenticatedExtendedCardRequest.model_validate(req_data)
+    assert req.method == 'agent/getAuthenticatedExtendedCard'
+    assert req.id == 5
+    # This request has no params, so we don't check for that.
+
+    with pytest.raises(ValidationError):  # Wrong method literal
+        GetAuthenticatedExtendedCardRequest.model_validate(
+            {**req_data, 'method': 'wrong/method'}
+        )
+
+    with pytest.raises(ValidationError):  # Missing id
+        GetAuthenticatedExtendedCardRequest.model_validate(
+            {'jsonrpc': '2.0', 'method': 'agent/getAuthenticatedExtendedCard'}
+        )
+
+
+def test_get_authenticated_extended_card_response() -> None:
+    resp_data: dict[str, Any] = {
+        'jsonrpc': '2.0',
+        'result': MINIMAL_AGENT_CARD,
+        'id': 'resp-1',
+    }
+    resp = GetAuthenticatedExtendedCardResponse.model_validate(resp_data)
+    assert resp.root.id == 'resp-1'
+    assert isinstance(resp.root, GetAuthenticatedExtendedCardSuccessResponse)
+    assert isinstance(resp.root.result, AgentCard)
+    assert resp.root.result.name == 'TestAgent'
+
+    with pytest.raises(ValidationError):  # Result is not an AgentCard
+        GetAuthenticatedExtendedCardResponse.model_validate(
+            {'jsonrpc': '2.0', 'result': {'wrong': 'data'}, 'id': 1}
+        )
+
+    resp_data_err: dict[str, Any] = {
+        'jsonrpc': '2.0',
+        'error': JSONRPCError(**TaskNotFoundError().model_dump()),
+        'id': 'resp-1',
+    }
+    resp_err = GetAuthenticatedExtendedCardResponse.model_validate(
+        resp_data_err
+    )
+    assert resp_err.root.id == 'resp-1'
+    assert isinstance(resp_err.root, JSONRPCErrorResponse)
+    assert resp_err.root.error is not None
+    assert isinstance(resp_err.root.error, JSONRPCError)