diff --git a/src/agents/models/openai_chatcompletions.py b/src/agents/models/openai_chatcompletions.py
index cbc48c50..e0aafad0 100644
--- a/src/agents/models/openai_chatcompletions.py
+++ b/src/agents/models/openai_chatcompletions.py
@@ -518,10 +518,8 @@ async def _fetch_response(
                 f"Response format: {response_format}\n"
             )
 
-        # Match the behavior of Responses where store is True when not given
-        store = model_settings.store if model_settings.store is not None else True
-
         reasoning_effort = model_settings.reasoning.effort if model_settings.reasoning else None
+        store = _Converter.get_store_param(self._get_client(), model_settings)
 
         ret = await self._get_client().chat.completions.create(
             model=self.model,
@@ -537,10 +535,10 @@ async def _fetch_response(
             parallel_tool_calls=parallel_tool_calls,
             stream=stream,
             stream_options={"include_usage": True} if stream else NOT_GIVEN,
-            store=store,
+            store=self._non_null_or_not_given(store),
             reasoning_effort=self._non_null_or_not_given(reasoning_effort),
             extra_headers=_HEADERS,
-            metadata=model_settings.metadata,
+            metadata=self._non_null_or_not_given(model_settings.metadata),
         )
 
         if isinstance(ret, ChatCompletion):
@@ -570,6 +568,12 @@ def _get_client(self) -> AsyncOpenAI:
 
 
 class _Converter:
+    @classmethod
+    def get_store_param(cls, client: AsyncOpenAI, model_settings: ModelSettings) -> bool | None:
+        # Match the behavior of Responses where store is True when not given
+        default_store = True if str(client.base_url).startswith("https://api.openai.com") else None
+        return model_settings.store if model_settings.store is not None else default_store
+
     @classmethod
     def convert_tool_choice(
         cls, tool_choice: Literal["auto", "required", "none"] | str | None
diff --git a/tests/test_openai_chatcompletions.py b/tests/test_openai_chatcompletions.py
index 9a53e2b7..a3198d33 100644
--- a/tests/test_openai_chatcompletions.py
+++ b/tests/test_openai_chatcompletions.py
@@ -5,7 +5,7 @@
 
 import httpx
 import pytest
-from openai import NOT_GIVEN
+from openai import NOT_GIVEN, AsyncOpenAI
 from openai.types.chat.chat_completion import ChatCompletion, Choice
 from openai.types.chat.chat_completion_chunk import ChatCompletionChunk
 from openai.types.chat.chat_completion_message import ChatCompletionMessage
@@ -31,6 +31,7 @@
     generation_span,
 )
 from agents.models.fake_id import FAKE_RESPONSES_ID
+from agents.models.openai_chatcompletions import _Converter
 
 
 @pytest.mark.allow_call_model_methods
@@ -226,7 +227,7 @@ def __init__(self, completions: DummyCompletions) -> None:
     # Ensure expected args were passed through to OpenAI client.
     kwargs = completions.kwargs
     assert kwargs["stream"] is False
-    assert kwargs["store"] is True
+    assert kwargs["store"] is NOT_GIVEN
     assert kwargs["model"] == "gpt-4"
     assert kwargs["messages"][0]["role"] == "system"
     assert kwargs["messages"][0]["content"] == "sys"
@@ -280,7 +281,7 @@ def __init__(self, completions: DummyCompletions) -> None:
         )
     # Check OpenAI client was called for streaming
     assert completions.kwargs["stream"] is True
-    assert completions.kwargs["store"] is True
+    assert completions.kwargs["store"] is NOT_GIVEN
     assert completions.kwargs["stream_options"] == {"include_usage": True}
     # Response is a proper openai Response
     assert isinstance(response, Response)
@@ -290,3 +291,39 @@ def __init__(self, completions: DummyCompletions) -> None:
     assert response.output == []
     # We returned the async iterator produced by our dummy.
     assert hasattr(stream, "__aiter__")
+
+
+def test_store_param():
+    """Should default to True for OpenAI API calls, and False otherwise."""
+
+    model_settings = ModelSettings()
+    client = AsyncOpenAI()
+    assert _Converter.get_store_param(client, model_settings) is True, (
+        "Should default to True for OpenAI API calls"
+    )
+
+    model_settings = ModelSettings(store=False)
+    assert _Converter.get_store_param(client, model_settings) is False, (
+        "Should respect explicitly set store=False"
+    )
+
+    model_settings = ModelSettings(store=True)
+    assert _Converter.get_store_param(client, model_settings) is True, (
+        "Should respect explicitly set store=True"
+    )
+
+    client = AsyncOpenAI(base_url="http://www.notopenai.com")
+    model_settings = ModelSettings()
+    assert _Converter.get_store_param(client, model_settings) is None, (
+        "Should default to None for non-OpenAI API calls"
+    )
+
+    model_settings = ModelSettings(store=False)
+    assert _Converter.get_store_param(client, model_settings) is False, (
+        "Should respect explicitly set store=False"
+    )
+
+    model_settings = ModelSettings(store=True)
+    assert _Converter.get_store_param(client, model_settings) is True, (
+        "Should respect explicitly set store=True"
+    )
diff --git a/uv.lock b/uv.lock
index e443c009..a6018eeb 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1087,7 +1087,7 @@ wheels = [
 
 [[package]]
 name = "openai-agents"
-version = "0.0.7"
+version = "0.0.8"
 source = { editable = "." }
 dependencies = [
     { name = "griffe" },