diff --git a/pydantic_ai_slim/pydantic_ai/models/openai.py b/pydantic_ai_slim/pydantic_ai/models/openai.py
index ce9b18e483..c5a57d5b05 100644
--- a/pydantic_ai_slim/pydantic_ai/models/openai.py
+++ b/pydantic_ai_slim/pydantic_ai/models/openai.py
@@ -948,6 +948,10 @@ def __init__(
 
         super().__init__(settings=settings, profile=profile or provider.model_profile)
 
+    @property
+    def base_url(self) -> str:
+        return str(self.client.base_url)
+
     @property
     def model_name(self) -> OpenAIModelName:
         """The model name."""
diff --git a/tests/models/test_openai_responses.py b/tests/models/test_openai_responses.py
index c8d7355e17..a9a7624b09 100644
--- a/tests/models/test_openai_responses.py
+++ b/tests/models/test_openai_responses.py
@@ -78,6 +78,8 @@ def test_openai_responses_model(env: TestEnv):
     model = OpenAIResponsesModel('gpt-4o')
     assert model.model_name == 'gpt-4o'
     assert model.system == 'openai'
+    assert model.base_url == 'https://api.openai.com/v1/'
+    assert model.client.api_key == 'test'
 
 
 async def test_openai_responses_model_simple_response(allow_model_requests: None, openai_api_key: str):