fix(azure): send only max_completion_tokens when both token params are set

litellm/llms/azure/chat/gpt_transformation.py

@@ -169,6 +169,8 @@ class AzureOpenAIConfig(BaseConfig):
             api_version_day = None
 
         for param, value in non_default_params.items():
+            if param == "max_tokens" and "max_completion_tokens" in non_default_params:
+                continue
             if param == "tool_choice":
                 """
                 This parameter requires API version 2023-12-01-preview or later

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

@@ -54,3 +54,39 @@ def test_map_openai_params_with_preview_api_version():
     assert config.map_openai_params(
         non_default_params, optional_params, model, drop_params, api_version
     )
+
+
+def test_map_openai_params_sends_only_max_completion_tokens_when_both_set():
+    config = AzureOpenAIConfig()
+    result = config.map_openai_params(
+        non_default_params={"max_tokens": 512, "max_completion_tokens": 256},
+        optional_params={},
+        model="gpt-4o",
+        drop_params=False,
+        api_version="2025-01-01-preview",
+    )
+    assert result == {"max_completion_tokens": 256}
+
+
+def test_map_openai_params_keeps_lone_max_tokens():
+    config = AzureOpenAIConfig()
+    result = config.map_openai_params(
+        non_default_params={"max_tokens": 512},
+        optional_params={},
+        model="gpt-4o",
+        drop_params=False,
+        api_version="2025-01-01-preview",
+    )
+    assert result == {"max_tokens": 512}
+
+
+def test_map_openai_params_keeps_lone_max_completion_tokens():
+    config = AzureOpenAIConfig()
+    result = config.map_openai_params(
+        non_default_params={"max_completion_tokens": 256},
+        optional_params={},
+        model="gpt-4o",
+        drop_params=False,
+        api_version="2025-01-01-preview",
+    )
+    assert result == {"max_completion_tokens": 256}