Add support for OpenAI verbosity parameter in Responses API

pydantic_ai_slim/pydantic_ai/models/openai.py

@@ -172,6 +172,14 @@ class OpenAIResponsesModelSettings(OpenAIModelSettings, total=False):
         middle of the conversation.
     """
 
+    openai_text_verbosity: Literal['low', 'medium', 'high']
+    """Constrains the verbosity of the model's text response.
+
+    Lower values will result in more concise responses, while higher values will
+    result in more verbose responses. Currently supported values are `low`,
+    `medium`, and `high`.
+    """
+
 
 @dataclass(init=False)
 class OpenAIModel(Model):
@@ -802,6 +810,12 @@ async def _responses_create(
             model_request_parameters.output_mode == 'prompted' and self.profile.supports_json_object_output
         ):  # pragma: no branch
             text = {'format': {'type': 'json_object'}}
+
+        # Add verbosity setting to text config if specified
+        if verbosity := model_settings.get('openai_text_verbosity'):
+            if text is None:
+                text = {}
+            text['verbosity'] = verbosity
 
             # Without this trick, we'd hit this error:
             # > Response input messages must contain the word 'json' in some form to use 'text.format' of type 'json_object'.

tests/models/test_openai_responses.py

@@ -1134,3 +1134,13 @@ async def get_user_country() -> str:
             ),
         ]
     )
+
+
+async def test_openai_responses_verbosity(allow_model_requests: None, openai_api_key: str):
+    """Test that verbosity setting is properly passed to the OpenAI API"""
+    model = OpenAIResponsesModel('gpt-4o', provider=OpenAIProvider(api_key=openai_api_key))
+    agent = Agent(model=model, model_settings=OpenAIResponsesModelSettings(openai_text_verbosity='low'))
+    result = await agent.run('Explain quantum computing briefly.')
+    # The response should exist (we don't need to check exact content since it depends on the model)
+    assert isinstance(result.output, str)
+    assert len(result.output) > 0