fix: preserve required IDs in OpenAI conversation items

src/agents/run_internal/session_persistence.py

@@ -569,12 +569,20 @@ def _sanitize_openai_conversation_item(item: TResponseInputItem) -> TResponseInp
     """Remove provider-specific fields before fingerprinting or persistence."""
     if isinstance(item, dict):
         clean_item = cast(dict[str, Any], strip_internal_input_item_metadata(item))
-        clean_item.pop("id", None)
+        if _should_strip_openai_conversation_item_id(clean_item):
+            clean_item.pop("id", None)
         clean_item.pop("provider_data", None)
         return cast(TResponseInputItem, clean_item)
     return item
 
 
+def _should_strip_openai_conversation_item_id(item: dict[str, Any]) -> bool:
+    """Return True when the Conversations API does not require an item's ``id`` field."""
+    # Built-in tool calls and assistant-authored items rely on their ids for replay. The only
+    # shapes we know are safe to drop are user messages and function_call_output items.
+    return item.get("role") == "user" or item.get("type") == "function_call_output"
+
+
 def _fingerprint_or_repr(item: TResponseInputItem, *, ignore_ids_for_matching: bool) -> str:
     """Fingerprint an item or fall back to repr when unavailable."""
     return fingerprint_input_item(item, ignore_ids_for_matching=ignore_ids_for_matching) or repr(

tests/test_agent_runner.py

@@ -2577,6 +2577,72 @@ async def test_save_result_to_session_sanitizes_original_input_items() -> None:
     assert "title" not in saved_tool_call
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "payload",
+    [
+        cast(
+            dict[str, Any],
+            {"type": "file_search_call", "id": "fs_123", "queries": ["customer profile"]},
+        ),
+        cast(
+            dict[str, Any],
+            {
+                "type": "web_search_call",
+                "id": "ws_123",
+                "action": {"type": "search", "query": "customer profile"},
+            },
+        ),
+        cast(
+            dict[str, Any],
+            {"type": "code_interpreter_call", "id": "ci_123", "status": "completed"},
+        ),
+    ],
+)
+async def test_save_result_to_session_preserves_required_built_in_tool_call_ids(
+    payload: dict[str, Any],
+) -> None:
+    class DummyOpenAIConversationsSession(OpenAIConversationsSession):
+        def __init__(self) -> None:
+            self.saved_items: list[TResponseInputItem] = []
+
+        async def _get_session_id(self) -> str:
+            return "conv_test"
+
+        async def add_items(self, items: list[TResponseInputItem]) -> None:
+            self.saved_items.extend(items)
+
+        async def get_items(self, limit: int | None = None) -> list[TResponseInputItem]:
+            return []
+
+        async def pop_item(self) -> TResponseInputItem | None:
+            return None
+
+        async def clear_session(self) -> None:
+            return None
+
+    session = DummyOpenAIConversationsSession()
+    agent = Agent(name="agent", model=FakeModel())
+    run_state: RunState[Any] = RunState(
+        context=RunContextWrapper(context={}),
+        original_input="input",
+        starting_agent=agent,
+        max_turns=1,
+    )
+
+    saved_count = await save_result_to_session(
+        session,
+        [],
+        cast(list[RunItem], [_DummyRunItem(payload)]),
+        run_state,
+    )
+
+    assert saved_count == 1
+    assert run_state._current_turn_persisted_item_count == 1
+    assert len(session.saved_items) == 1
+    assert cast(dict[str, Any], session.saved_items[0])["id"] == payload["id"]
+
+
 @pytest.mark.asyncio
 async def test_prepare_input_with_session_strips_internal_tool_call_metadata() -> None:
     tool_call = cast(

tests/test_run_internal_items.py

@@ -23,7 +23,7 @@
 from agents.models.fake_id import FAKE_RESPONSES_ID
 from agents.result import RunResult
 from agents.run_context import RunContextWrapper
-from agents.run_internal import items as run_items
+from agents.run_internal import items as run_items, session_persistence as session_persistence
 
 
 def test_drop_orphan_function_calls_preserves_non_mapping_entries() -> None:
@@ -533,6 +533,69 @@ def test_fingerprint_input_item_ignores_internal_tool_call_metadata() -> None:
     )
 
 
+def test_sanitize_openai_conversation_item_preserves_required_tool_call_ids() -> None:
+    file_search_call = cast(
+        TResponseInputItem,
+        {
+            "type": "file_search_call",
+            "id": "fs_123",
+            "queries": ["customer profile"],
+            "status": "completed",
+        },
+    )
+    web_search_call = cast(
+        TResponseInputItem,
+        {
+            "type": "web_search_call",
+            "id": "ws_123",
+            "action": {"type": "search", "query": "customer profile"},
+            "status": "completed",
+        },
+    )
+    code_interpreter_call = cast(
+        TResponseInputItem,
+        {
+            "type": "code_interpreter_call",
+            "id": "ci_123",
+            "status": "completed",
+        },
+    )
+    user_message = cast(
+        TResponseInputItem,
+        {"role": "user", "id": "user_123", "content": "hello"},
+    )
+    function_call_output = cast(
+        TResponseInputItem,
+        {"type": "function_call_output", "id": "out_123", "call_id": "call_123", "output": "ok"},
+    )
+
+    assert (
+        cast(
+            dict[str, Any], session_persistence._sanitize_openai_conversation_item(file_search_call)
+        )["id"]
+        == "fs_123"
+    )
+    assert (
+        cast(
+            dict[str, Any], session_persistence._sanitize_openai_conversation_item(web_search_call)
+        )["id"]
+        == "ws_123"
+    )
+    assert (
+        cast(
+            dict[str, Any],
+            session_persistence._sanitize_openai_conversation_item(code_interpreter_call),
+        )["id"]
+        == "ci_123"
+    )
+    assert "id" not in cast(
+        dict[str, Any], session_persistence._sanitize_openai_conversation_item(user_message)
+    )
+    assert "id" not in cast(
+        dict[str, Any], session_persistence._sanitize_openai_conversation_item(function_call_output)
+    )
+
+
 def test_run_result_to_input_list_preserves_tool_search_items() -> None:
     agent = Agent(name="A")
     result = RunResult(