fix(core): #772 avoid noisy pydantic serialization warnings for model_dump items (#2443)

Author: OiPunk

src/agents/run_internal/items.py

@@ -116,8 +116,11 @@ def fingerprint_input_item(item: Any, *, ignore_ids_for_matching: bool = False)
         return None
 
     try:
+        payload: Any
         if hasattr(item, "model_dump"):
-            payload = item.model_dump(exclude_unset=True)
+            payload = _model_dump_without_warnings(item)
+            if payload is None:
+                return None
         elif isinstance(item, dict):
             payload = dict(item)
             if ignore_ids_for_matching:
@@ -314,13 +317,25 @@ def _coerce_to_dict(value: object) -> dict[str, Any] | None:
     if isinstance(value, dict):
         return dict(value)
     if isinstance(value, BaseModel):
-        try:
-            return value.model_dump(exclude_unset=True)
-        except Exception:
-            return None
+        return _model_dump_without_warnings(value)
     if hasattr(value, "model_dump"):
+        return _model_dump_without_warnings(value)
+    return None
+
+
+def _model_dump_without_warnings(value: object) -> dict[str, Any] | None:
+    """Best-effort model_dump that avoids noisy serialization warnings from third-party models."""
+    if not hasattr(value, "model_dump"):
+        return None
+
+    model_dump = cast(Any, value).model_dump
+    try:
+        return cast(dict[str, Any], model_dump(exclude_unset=True, warnings=False))
+    except TypeError:
+        # Some model_dump-compatible objects only accept exclude_unset.
         try:
-            return cast(dict[str, Any], value.model_dump(exclude_unset=True))
+            return cast(dict[str, Any], model_dump(exclude_unset=True))
         except Exception:
             return None
-    return None
+    except Exception:
+        return None

tests/test_agent_runner.py

@@ -3,6 +3,7 @@
 import asyncio
 import json
 import tempfile
+import warnings
 from pathlib import Path
 from typing import Any, cast
 from unittest.mock import patch
@@ -11,6 +12,7 @@
 import pytest
 from openai import BadRequestError
 from openai.types.responses import ResponseFunctionToolCall
+from openai.types.responses.response_output_text import AnnotationFileCitation, ResponseOutputText
 from typing_extensions import TypedDict
 
 from agents import (
@@ -48,6 +50,7 @@
 from agents.run_internal.items import (
     drop_orphan_function_calls,
     ensure_input_item_format,
+    fingerprint_input_item,
     normalize_input_items_for_api,
     normalize_resumed_input,
 )
@@ -329,6 +332,14 @@ def testnormalize_input_items_for_api_preserves_provider_data():
     assert second["provider_data"] == {"trace": "remove"}
 
 
+def test_fingerprint_input_item_returns_none_when_model_dump_fails():
+    class _BrokenModelDump:
+        def model_dump(self, *_args: Any, **_kwargs: Any) -> dict[str, Any]:
+            raise RuntimeError("model_dump failed")
+
+    assert fingerprint_input_item(_BrokenModelDump()) is None
+
+
 def test_server_conversation_tracker_tracks_previous_response_id():
     tracker = OpenAIServerConversationTracker(conversation_id=None, previous_response_id="resp_a")
     response = ModelResponse(
@@ -1310,6 +1321,29 @@ def model_dump(self, exclude_unset: bool = True) -> dict[str, Any]:
     assert converted["output"] == "dumped"
 
 
+def test_ensure_api_input_item_avoids_pydantic_serialization_warnings():
+    annotation = AnnotationFileCitation.model_construct(
+        type="container_file_citation",
+        file_id="file_123",
+        filename="result.txt",
+        index=0,
+    )
+    output_text = ResponseOutputText.model_construct(
+        type="output_text",
+        text="done",
+        annotations=[annotation],
+    )
+
+    with warnings.catch_warnings(record=True) as captured:
+        warnings.simplefilter("always")
+        converted = ensure_input_item_format(cast(Any, output_text))
+
+    converted_payload = cast(dict[str, Any], converted)
+    assert captured == []
+    assert converted_payload["type"] == "output_text"
+    assert converted_payload["annotations"][0]["type"] == "container_file_citation"
+
+
 def test_ensure_api_input_item_preserves_object_output():
     payload = cast(
         TResponseInputItem,