[BREAKING] Python: clean up kwargs across agents, chat clients, tools, and sessions (#4581)

* Python: clean up kwargs across agents, chat clients, tools, and sessions (#3642)

Audit and refactor public **kwargs usage across core agents, chat clients,
tools, sessions, and provider packages per the migration strategy codified
in CODING_STANDARD.md.

Key changes:
- Add explicit runtime buckets: function_invocation_kwargs and client_kwargs
  on RawAgent.run() and chat client get_response() layers.
- Refactor FunctionTool to prefer explicit ctx: FunctionInvocationContext
  injection; legacy **kwargs tools still work via _forward_runtime_kwargs.
- Refactor Agent.as_tool() to use direct JSON schema, always-streaming
  wrapper, approval_mode parameter, and UserInputRequiredException
  propagation (integrates PR #4568 behavior).
- Remove implicit session bleeding into FunctionInvocationContext; tools
  that need a session must receive it via function_invocation_kwargs.
- Lower chat-client layers after FunctionInvocationLayer accept only
  compatibility **kwargs (client_kwargs flattened, function_invocation_kwargs
  ignored).
- Add layered docstring composition from Raw... implementations via
  _docstrings.py helper.
- Clean up provider constructors to use explicit additional_properties.
- Deprecation warnings on legacy direct kwargs paths.
- Update samples, tests, and typing across all 23 packages.

Resolves #3642

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* clarified docstring

* feedback fixes

* Add unit tests for _docstrings.py build/apply helpers

Tests cover: no docstring source, no extra kwargs, appending to existing
Keyword Args section, inserting after Args, inserting in plain docstrings,
multiline descriptions, ordering, and apply_layered_docstring.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add test for propagate_session TypeError on non-AgentSession values

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add tests for multi-content and empty UserInputRequiredException propagation

Cover the branching logic in _try_execute_function_calls for:
- Multiple user_input_request items in a single exception (extra_user_input_contents path)
- Empty contents list (fallback function_result path)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add tests for DurableAIAgent.get_session forwarding service_session_id

Verifies get_session correctly forwards service_session_id and session_id
to the executor's get_new_session, replacing the removed kwargs test.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Simplify ag-ui test stub to read session from client_kwargs only

Remove dual-mode detection (client_kwargs vs raw kwargs fallback) from
the test mock. Session is now read exclusively from client_kwargs,
matching the settled public calling convention.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* updated create and get sessions in durable

* fixed docstrings

* fix test

* updated session handling

* updated from main

* updated tests

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/packages/ag-ui/agent_framework_ag_ui/_client.py

@@ -220,7 +220,6 @@ class AGUIChatClient(
         additional_properties: dict[str, Any] | None = None,
         middleware: Sequence[ChatAndFunctionMiddlewareTypes] | None = None,
         function_invocation_configuration: FunctionInvocationConfiguration | None = None,
-        **kwargs: Any,
     ) -> None:
         """Initialize the AG-UI chat client.
 
@@ -231,13 +230,11 @@ class AGUIChatClient(
             additional_properties: Additional properties to store
             middleware: Optional middleware to apply to the client.
             function_invocation_configuration: Optional function invocation configuration override.
-            **kwargs: Additional arguments passed to BaseChatClient
         """
         super().__init__(
             additional_properties=additional_properties,
             middleware=middleware,
             function_invocation_configuration=function_invocation_configuration,
-            **kwargs,
         )
         self._http_service = AGUIHttpService(
             endpoint=endpoint,

python/packages/ag-ui/tests/ag_ui/conftest.py

@@ -98,7 +98,11 @@ class StreamingChatClientStub(
         options: OptionsCoT | ChatOptions[Any] | None = None,
         **kwargs: Any,
     ) -> Awaitable[ChatResponse[Any]] | ResponseStream[ChatResponseUpdate, ChatResponse[Any]]:
-        self.last_session = kwargs.get("session")
+        client_kwargs = kwargs.get("client_kwargs")
+        if isinstance(client_kwargs, Mapping):
+            self.last_session = cast(AgentSession | None, client_kwargs.get("session"))
+        else:
+            self.last_session = None
         self.last_service_session_id = self.last_session.service_session_id if self.last_session else None
         return cast(
             Awaitable[ChatResponse[Any]] | ResponseStream[ChatResponseUpdate, ChatResponse[Any]],

python/packages/ag-ui/tests/ag_ui/test_agent_wrapper_comprehensive.py

@@ -702,14 +702,9 @@ async def test_agent_with_use_service_session_is_true(streaming_chat_client_stub
     """Test that when use_service_session is True, the AgentSession used to run the agent is set to the service session ID."""
     from agent_framework.ag_ui import AgentFrameworkAgent
 
-    request_service_session_id: str | None = None
-
     async def stream_fn(
         messages: MutableSequence[Message], chat_options: ChatOptions, **kwargs: Any
     ) -> AsyncIterator[ChatResponseUpdate]:
-        nonlocal request_service_session_id
-        session = kwargs.get("session")
-        request_service_session_id = session.service_session_id if session else None
         yield ChatResponseUpdate(
             contents=[Content.from_text(text="Response")], response_id="resp_67890", conversation_id="conv_12345"
         )
@@ -719,11 +714,22 @@ async def test_agent_with_use_service_session_is_true(streaming_chat_client_stub
 
     input_data = {"messages": [{"role": "user", "content": "Hi"}], "thread_id": "conv_123456"}
 
+    # Spy on agent.run to capture the session kwarg at call time (before streaming mutates it)
+    captured_service_session_id: str | None = None
+    original_run = agent.run
+
+    def capturing_run(*args: Any, **kwargs: Any) -> Any:
+        nonlocal captured_service_session_id
+        session = kwargs.get("session")
+        captured_service_session_id = session.service_session_id if session else None
+        return original_run(*args, **kwargs)
+
+    agent.run = capturing_run  # type: ignore[assignment, method-assign]
+
     events: list[Any] = []
     async for event in wrapper.run(input_data):
         events.append(event)
-    request_service_session_id = agent.client.last_service_session_id
-    assert request_service_session_id == "conv_123456"  # type: ignore[attr-defined] (service_session_id should be set)
+    assert captured_service_session_id == "conv_123456"
 
 
 async def test_function_approval_mode_executes_tool(streaming_chat_client_stub):