feat(api): add phase field to conversations message

Author: stainless-app[bot]

.stats.yml

@@ -1,4 +1,4 @@
 configured_endpoints: 152
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai%2Fopenai-2fab88288cbbe872f5d61d1d47da2286662a123b4312bc7fc36addba6607cd67.yml
-openapi_spec_hash: a7ee80374e409ed9ecc8ea2e3cd31071
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai%2Fopenai-89e54b8e2c185d30e869f73e7798308d56a6a835a675d54628dd86836f147879.yml
+openapi_spec_hash: 85b0dd465aa1a034f2764b0758671f21
 config_hash: 5635033cdc8c930255f8b529a78de722

src/openai/types/conversations/message.py

@@ -1,6 +1,6 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
-from typing import List, Union
+from typing import List, Union, Optional
 from typing_extensions import Literal, Annotated, TypeAlias
 
 from ..._utils import PropertyInfo
@@ -68,3 +68,11 @@ class Message(BaseModel):
 
     type: Literal["message"]
     """The type of the message. Always set to `message`."""
+
+    phase: Optional[Literal["commentary", "final_answer"]] = None
+    """
+    Labels an `assistant` message as intermediate commentary (`commentary`) or the
+    final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+    sending follow-up requests, preserve and resend phase on all assistant messages
+    — dropping it can degrade performance. Not used for user messages.
+    """