Python: Preserve tool call IDs in chat history XML

python/semantic_kernel/contents/function_call_content.py

@@ -205,6 +205,8 @@ def to_element(self) -> Element:
         element = Element(self.tag)
         if self.id:
             element.set("id", self.id)
+        if self.call_id:
+            element.set("call_id", self.call_id)
         if self.name:
             element.set("name", self.name)
         if self.arguments:
@@ -217,7 +219,12 @@ def from_element(cls: type[_T], element: Element) -> _T:
         if element.tag != cls.tag:
             raise ContentInitializationError(f"Element tag is not {cls.tag}")  # pragma: no cover
 
-        return cls(name=element.get("name"), id=element.get("id"), arguments=element.text or "")
+        return cls(
+            name=element.get("name"),
+            id=element.get("id"),
+            call_id=element.get("call_id"),
+            arguments=element.text or "",
+        )
 
     def to_dict(self) -> dict[str, str | Any]:
         """Convert the instance to a dictionary."""

python/semantic_kernel/contents/function_result_content.py

@@ -106,6 +106,8 @@ def to_element(self) -> Element:
         element = Element(self.tag)
         if self.id:
             element.set("id", self.id)
+        if self.call_id:
+            element.set("call_id", self.call_id)
         if self.name:
             element.set("name", self.name)
         element.text = str(self.result)
@@ -116,7 +118,12 @@ def from_element(cls: type[_T], element: Element) -> _T:
         """Create an instance from an Element."""
         if element.tag != cls.tag:
             raise ContentInitializationError(f"Element tag is not {cls.tag}")  # pragma: no cover
-        return cls(id=element.get("id", ""), result=element.text, name=element.get("name", None))
+        return cls(
+            id=element.get("id", ""),
+            call_id=element.get("call_id"),
+            result=element.text,
+            name=element.get("name", None),
+        )
 
     @classmethod
     def from_function_call_content_and_result(

python/tests/unit/agents/openai_responses/test_openai_responses_thread_actions.py

@@ -23,6 +23,40 @@
 from semantic_kernel.functions import KernelArguments
 
 
+@pytest.mark.parametrize("store_enabled", [False, True])
+def test_prepare_request_preserves_call_ids_after_xml_roundtrip(store_enabled):
+    from semantic_kernel.contents import ChatHistory, FunctionCallContent, FunctionResultContent
+
+    function_call = FunctionCallContent(
+        id="fc_item_123", call_id="call_correlation_456", name="weather", arguments='{"city":"Seattle"}'
+    )
+    history = ChatHistory(
+        messages=[
+            ChatMessageContent(role=AuthorRole.ASSISTANT, items=[function_call]),
+            ChatMessageContent(
+                role=AuthorRole.TOOL,
+                items=[FunctionResultContent.from_function_call_content_and_result(function_call, "Sunny")],
+            ),
+        ]
+    )
+
+    restored = ChatHistory.from_rendered_prompt(history.to_prompt())
+    request = ResponsesAgentThreadActions._prepare_chat_history_for_request(restored, store_enabled=store_enabled)
+
+    expected = [{"type": "function_call_output", "call_id": "call_correlation_456", "output": "Sunny"}]
+    if not store_enabled:
+        expected.insert(
+            0,
+            {
+                "type": "function_call",
+                "call_id": "call_correlation_456",
+                "name": "weather",
+                "arguments": '{"city":"Seattle"}',
+            },
+        )
+    assert request == expected
+
+
 @pytest.fixture
 def mock_agent():
     agent = AsyncMock(spec=OpenAIResponsesAgent)

python/tests/unit/contents/test_chat_history.py

@@ -46,6 +46,34 @@ def test_init_with_messages_only():
     assert chat_history.messages == msgs, "Chat history should contain exactly the provided messages"
 
 
+@pytest.mark.parametrize("call_id", [None, "call_correlation_456"])
+@pytest.mark.parametrize("serializer", [str, ChatHistory.to_prompt])
+def test_xml_roundtrip_preserves_function_call_ids(call_id, serializer):
+    function_call = FunctionCallContent(
+        id="fc_item_123", call_id=call_id, name="weather-get_weather", arguments='{"city":"Seattle"}'
+    )
+    function_result = FunctionResultContent.from_function_call_content_and_result(function_call, "Sunny")
+    history = ChatHistory(
+        messages=[
+            ChatMessageContent(role=AuthorRole.ASSISTANT, items=[function_call]),
+            ChatMessageContent(role=AuthorRole.TOOL, items=[function_result]),
+        ]
+    )
+
+    restored = ChatHistory.from_rendered_prompt(serializer(history))
+
+    assert len(restored.messages) == 2
+    restored_call = restored.messages[0].items[0]
+    restored_result = restored.messages[1].items[0]
+    assert isinstance(restored_call, FunctionCallContent)
+    assert isinstance(restored_result, FunctionResultContent)
+    assert restored_call.id == restored_result.id == "fc_item_123"
+    assert restored_call.call_id == restored_result.call_id == call_id
+    assert restored_call.name == restored_result.name == "weather-get_weather"
+    assert restored_call.arguments == '{"city":"Seattle"}'
+    assert restored_result.result == "Sunny"
+
+
 def test_init_with_messages_and_system_message():
     system_msg = "a test system prompt"
     msgs = [ChatMessageContent(role=AuthorRole.USER, content=f"Message {i}") for i in range(3)]