Add an after model validator ensuring temp=1 for o1 models

paperqa/settings.py

@@ -675,6 +675,20 @@ def _deprecated_field(self) -> Self:
                 setattr(self.agent.index, new_name, value)  # Propagate to new location
         return self
 
+    @model_validator(mode="after")
+    def _validate_temperature_for_o1_preview(self) -> Self:
+        """Ensures temperature is 1 if the LLM is 'o1-preview' or 'o1-mini'.
+
+        o1 reasoning models only support temperature = 1.  See
+        https://platform.openai.com/docs/guides/reasoning/quickstart
+        """
+        if self.llm.startswith("o1-") and self.temperature != 1:
+            raise ValueError(
+                "When dealing with OpenAI o1 models, the temperature"
+                f" must be set to 1, {self.temperature} was specified."
+            )
+        return self
+
     @computed_field  # type: ignore[prop-decorator]
     @property
     def md5(self) -> str:

tests/test_configs.py

@@ -67,3 +67,9 @@ def test_router_kwargs_present_in_models() -> None:
     settings = Settings()
     assert settings.get_llm().config["router_kwargs"] is not None
     assert settings.get_summary_llm().config["router_kwargs"] is not None
+
+
+def test_o1_requires_temp_equals_1() -> None:
+    with pytest.raises(ValidationError):
+        _ = Settings(llm="o1-thismodeldoesnotexist", temperature=0)
+    _ = Settings(llm="o1-thismodeldoesnotexist", temperature=1)