diff --git a/python/packages/openai/agent_framework_openai/_chat_client.py b/python/packages/openai/agent_framework_openai/_chat_client.py
index 5b7584dc6d..c8a41a204f 100644
--- a/python/packages/openai/agent_framework_openai/_chat_client.py
+++ b/python/packages/openai/agent_framework_openai/_chat_client.py
@@ -2028,6 +2028,7 @@ def _parse_chunk_from_openai(
         local_shell_tool_name = self._get_local_shell_tool_name(options.get("tools"))
         conversation_id: str | None = None
         response_id: str | None = None
+        created_at: str | None = None
         continuation_token: OpenAIContinuationToken | None = None
         model = self.model
         match event.type:
@@ -2209,6 +2210,9 @@ def _parse_chunk_from_openai(
                 response_id = event.response.id
                 conversation_id = self._get_conversation_id(event.response, options.get("store"))
                 model = event.response.model
+                created_at = datetime.fromtimestamp(event.response.created_at, tz=timezone.utc).strftime(
+                    "%Y-%m-%dT%H:%M:%S.%fZ"
+                )
                 if event.response.usage:
                     usage = self._parse_usage_from_openai(event.response.usage)
                     if usage:
@@ -2589,6 +2593,7 @@ def _get_ann_value(key: str) -> Any:
             response_id=response_id,
             role="assistant",
             model=model,
+            created_at=created_at,
             continuation_token=continuation_token,
             additional_properties=metadata,
             raw_representation=event,
diff --git a/python/packages/openai/tests/openai/test_openai_chat_client.py b/python/packages/openai/tests/openai/test_openai_chat_client.py
index 8c956a6339..7624f30b65 100644
--- a/python/packages/openai/tests/openai/test_openai_chat_client.py
+++ b/python/packages/openai/tests/openai/test_openai_chat_client.py
@@ -2192,6 +2192,7 @@ def test_streaming_chunk_with_usage_only() -> None:
     mock_event.response.id = "resp_usage"
     mock_event.response.model = "test-model"
     mock_event.response.conversation = None
+    mock_event.response.created_at = 1000000000.0
     mock_event.response.usage = MagicMock()
     mock_event.response.usage.input_tokens = 50
     mock_event.response.usage.output_tokens = 25
@@ -4438,6 +4439,7 @@ def test_streaming_response_completed_no_continuation_token() -> None:
     mock_event.response.conversation = MagicMock()
     mock_event.response.conversation.id = "conv_done"
     mock_event.response.model = "test-model"
+    mock_event.response.created_at = 1000000000.0
     mock_event.response.usage = None
 
     update = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
@@ -4445,6 +4447,28 @@ def test_streaming_response_completed_no_continuation_token() -> None:
     assert update.continuation_token is None
 
 
+def test_streaming_response_completed_sets_created_at() -> None:
+    """Test that response.completed sets created_at on the ChatResponseUpdate."""
+    client = OpenAIChatClient(model="test-model", api_key="test-key")
+    chat_options: dict[str, Any] = {}
+    function_call_ids: dict[int, tuple[str, str]] = {}
+
+    mock_event = MagicMock()
+    mock_event.type = "response.completed"
+    mock_event.response = MagicMock()
+    mock_event.response.id = "resp_created"
+    mock_event.response.conversation = MagicMock()
+    mock_event.response.conversation.id = "conv_created"
+    mock_event.response.model = "test-model"
+    mock_event.response.created_at = 1000000000.0
+    mock_event.response.usage = None
+
+    update = client._parse_chunk_from_openai(mock_event, chat_options, function_call_ids)
+
+    assert update.created_at is not None
+    assert update.created_at == "2001-09-09T01:46:40.000000Z"
+
+
 def test_map_chat_to_agent_update_preserves_continuation_token() -> None:
     """Test that map_chat_to_agent_update propagates continuation_token."""
     from agent_framework._types import map_chat_to_agent_update
diff --git a/python/samples/02-agents/conversations/file_history_provider.py b/python/samples/02-agents/conversations/file_history_provider.py
index 04a87f8224..20735ffd17 100644
--- a/python/samples/02-agents/conversations/file_history_provider.py
+++ b/python/samples/02-agents/conversations/file_history_provider.py
@@ -21,7 +21,7 @@
 from pydantic import Field
 
 try:
-    import orjson
+    import orjson  # pyright: ignore[reportMissingImports]
 except ImportError:
     orjson = None
 
diff --git a/python/samples/02-agents/conversations/file_history_provider_conversation_persistence.py b/python/samples/02-agents/conversations/file_history_provider_conversation_persistence.py
index 70c5d7e8e8..693501b0f9 100644
--- a/python/samples/02-agents/conversations/file_history_provider_conversation_persistence.py
+++ b/python/samples/02-agents/conversations/file_history_provider_conversation_persistence.py
@@ -22,7 +22,7 @@
 from pydantic import Field
 
 try:
-    import orjson
+    import orjson  # pyright: ignore[reportMissingImports]
 except ImportError:
     orjson = None