fix(azure): drop unsupported gpt-5.5 temperature

litellm/llms/azure/chat/gpt_5_transformation.py

@@ -18,6 +18,11 @@ class AzureOpenAIGPT5Config(AzureOpenAIConfig, OpenAIGPT5Config):
 
     GPT5_SERIES_ROUTE = "gpt5_series/"
 
+    @classmethod
+    def _rejects_non_default_temperature(cls, model: str) -> bool:
+        model_name = model.split("/")[-1]
+        return model_name.startswith(("gpt-5.5", "gpt-5.6"))
+
     @classmethod
     def _supports_reasoning_effort_level(cls, model: str, level: str) -> bool:
         """Override to handle gpt5_series/ prefix used for Azure routing.
@@ -93,6 +98,20 @@ class AzureOpenAIGPT5Config(AzureOpenAIConfig, OpenAIGPT5Config):
         drop_params: bool,
         api_version: str = "",
     ) -> dict:
+        temperature_value = non_default_params.get("temperature")
+        if self._rejects_non_default_temperature(model) and temperature_value not in (None, 1):
+            if litellm.drop_params is True or drop_params is True:
+                non_default_params = {key: value for key, value in non_default_params.items() if key != "temperature"}
+            else:
+                raise UnsupportedParamsError(
+                    status_code=400,
+                    message=(
+                        f"Azure OpenAI {model} does not support temperature={temperature_value}. "
+                        "Only temperature=1 is supported. "
+                        "To drop unsupported params set `litellm.drop_params = True`"
+                    ),
+                )
+
         reasoning_effort_value = non_default_params.get("reasoning_effort") or optional_params.get("reasoning_effort")
         effective_effort = _get_effort_level(reasoning_effort_value)
 

tests/test_litellm/llms/azure/chat/test_azure_gpt5_transformation.py

@@ -50,6 +50,75 @@ def test_azure_gpt5_temperature_error(config: AzureOpenAIGPT5Config):
         )
 
 
+@pytest.mark.parametrize(
+    "model",
+    [
+        "azure/gpt-5.5",
+        "azure/gpt-5.5-2026-04-23",
+        "azure/gpt-5.6",
+        "azure/gpt-5.6-luna",
+        "azure/gpt-5.6-sol",
+        "azure/gpt-5.6-terra",
+        "gpt5_series/gpt-5.6-luna",
+    ],
+)
+def test_azure_gpt5_5_and_5_6_non_default_temperature(
+    config: AzureOpenAIGPT5Config,
+    model: str,
+    monkeypatch: pytest.MonkeyPatch,
+):
+    assert (
+        config.map_openai_params(
+            non_default_params={"temperature": 0.3},
+            optional_params={},
+            model=model,
+            drop_params=True,
+        )
+        == {}
+    )
+
+    monkeypatch.setattr(litellm, "drop_params", True)
+    assert (
+        config.map_openai_params(
+            non_default_params={"temperature": 0.3},
+            optional_params={},
+            model=model,
+            drop_params=False,
+        )
+        == {}
+    )
+
+    monkeypatch.setattr(litellm, "drop_params", False)
+    with pytest.raises(litellm.utils.UnsupportedParamsError):
+        config.map_openai_params(
+            non_default_params={"temperature": 0.3},
+            optional_params={},
+            model=model,
+            drop_params=False,
+        )
+
+
+@pytest.mark.parametrize(
+    ("model", "temperature"),
+    [
+        ("azure/gpt-5.4", 0.3),
+        ("azure/gpt-5.5", 1),
+        ("azure/gpt-5.6-sol", 1.0),
+    ],
+)
+def test_azure_gpt5_temperature_supported_values_unchanged(
+    config: AzureOpenAIGPT5Config,
+    model: str,
+    temperature: float,
+):
+    assert config.map_openai_params(
+        non_default_params={"temperature": temperature},
+        optional_params={},
+        model=model,
+        drop_params=False,
+    )["temperature"] == temperature
+
+
 def test_azure_gpt5_series_transform_request(config: AzureOpenAIGPT5Config):
     request = config.transform_request(
         model="gpt5_series/gpt-5",