fix(azure): Strip operation suffixes from deployment URLs to prevent 404 errors

litellm/llms/azure/common_utils.py

@@ -1,5 +1,6 @@
 import json
 import os
+import re
 from typing import Any, Callable, Dict, Literal, Optional, Union, cast
 
 import httpx
@@ -255,12 +256,33 @@ def get_azure_ad_token_from_oidc(
 
 
 def select_azure_base_url_or_endpoint(azure_client_params: dict):
+    """
+    Determines whether to use azure_endpoint or base_url for the Azure OpenAI client.
+
+    When api_base contains deployment-specific paths (e.g., /openai/deployments/gpt-4o/chat/completions),
+    it should be used as base_url. However, operation-specific suffixes like /chat/completions must be
+    stripped because the Azure SDK will append them again when making requests.
+
+    Args:
+        azure_client_params: Dictionary containing azure_endpoint and other client parameters.
+
+    Returns:
+        Updated azure_client_params with either azure_endpoint or base_url set correctly.
+    """
     azure_endpoint = azure_client_params.get("azure_endpoint", None)
     if azure_endpoint is not None:
         # see : https://github.com/openai/openai-python/blob/3d61ed42aba652b547029095a7eb269ad4e1e957/src/openai/lib/azure.py#L192
         if "/openai/deployments" in azure_endpoint:
             # this is base_url, not an azure_endpoint
-            azure_client_params["base_url"] = azure_endpoint
+            # Strip operation-specific suffixes that the SDK will append again
+            # e.g., /chat/completions, /completions, /embeddings, etc.
+            base_url = re.sub(
+                r"/(chat/completions|completions|embeddings|audio/speech|audio/transcriptions|images/generations)/?$",
+                "",
+                azure_endpoint,
+            )
+            base_url = base_url.rstrip("/")
+            azure_client_params["base_url"] = base_url
             azure_client_params.pop("azure_endpoint")
 
     return azure_client_params

tests/test_litellm/llms/azure/test_azure_common_utils.py

@@ -1524,3 +1524,169 @@ def test_is_azure_v1_api_version(api_version, expected):
     """
     result = BaseAzureLLM._is_azure_v1_api_version(api_version=api_version)
     assert result == expected
+
+
+# Tests for select_azure_base_url_or_endpoint URL sanitization
+from litellm.llms.azure.common_utils import select_azure_base_url_or_endpoint
+
+
+class TestSelectAzureBaseUrlOrEndpoint:
+    """Tests for select_azure_base_url_or_endpoint URL sanitization."""
+
+    def test_strips_chat_completions_suffix(self):
+        """
+        Test that /chat/completions is stripped from deployment URLs.
+
+        When api_base is configured as:
+        https://xxx.openai.azure.com/openai/deployments/gpt-4o/chat/completions
+
+        The Azure SDK will append /chat/completions again, causing:
+        https://xxx.openai.azure.com/openai/deployments/gpt-4o/chat/completions/chat/completions
+
+        This results in a 404 error from Azure.
+        """
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o/chat/completions"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o"
+        )
+        assert "base_url" in result, "Should have base_url when deployment path detected"
+        assert "azure_endpoint" not in result, "Should remove azure_endpoint"
+        assert (
+            result["base_url"] == expected_base_url
+        ), f"Expected {expected_base_url}, got {result['base_url']}"
+
+    def test_strips_completions_suffix(self):
+        """Test that /completions suffix is stripped for text completion endpoints."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o/completions"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_strips_embeddings_suffix(self):
+        """Test that /embeddings suffix is stripped for embedding endpoints."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/text-embedding-ada-002/embeddings"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = "https://ai-azure-product-dev.openai.azure.com/openai/deployments/text-embedding-ada-002"
+        assert result["base_url"] == expected_base_url
+
+    def test_strips_audio_speech_suffix(self):
+        """Test that /audio/speech suffix is stripped for TTS endpoints."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/tts-1/audio/speech"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/tts-1"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_strips_audio_transcriptions_suffix(self):
+        """Test that /audio/transcriptions suffix is stripped for transcription endpoints."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/whisper-1/audio/transcriptions"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/whisper-1"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_strips_images_generations_suffix(self):
+        """Test that /images/generations suffix is stripped for image generation endpoints."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/dall-e-3/images/generations"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/dall-e-3"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_preserves_deployment_path_without_suffix(self):
+        """Test that deployment paths without operation suffixes are preserved."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_no_deployment_path_keeps_azure_endpoint(self):
+        """Test that URLs without deployment paths keep azure_endpoint."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        # Should keep azure_endpoint since there's no deployment path
+        assert "azure_endpoint" in result
+        assert "base_url" not in result
+        assert (
+            result["azure_endpoint"]
+            == "https://ai-azure-product-dev.openai.azure.com"
+        )
+
+    def test_handles_trailing_slash(self):
+        """Test that trailing slashes are handled correctly."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o/chat/completions/"
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        expected_base_url = (
+            "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o"
+        )
+        assert result["base_url"] == expected_base_url
+
+    def test_preserves_other_params(self):
+        """Test that other parameters in the dict are preserved."""
+        azure_client_params = {
+            "azure_endpoint": "https://ai-azure-product-dev.openai.azure.com/openai/deployments/gpt-4o/chat/completions",
+            "api_key": "test-key",
+            "api_version": "2023-05-15",
+            "azure_ad_token": "test-token",
+        }
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        assert result["api_key"] == "test-key"
+        assert result["api_version"] == "2023-05-15"
+        assert result["azure_ad_token"] == "test-token"
+        assert "base_url" in result
+        assert "azure_endpoint" not in result
+
+    def test_none_azure_endpoint(self):
+        """Test that None azure_endpoint is handled gracefully."""
+        azure_client_params = {"azure_endpoint": None, "api_key": "test-key"}
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        # Should return params unchanged
+        assert result["azure_endpoint"] is None
+        assert result["api_key"] == "test-key"
+        assert "base_url" not in result
+
+    def test_missing_azure_endpoint(self):
+        """Test that missing azure_endpoint is handled gracefully."""
+        azure_client_params = {"api_key": "test-key"}
+        result = select_azure_base_url_or_endpoint(azure_client_params)
+
+        # Should return params unchanged
+        assert result["api_key"] == "test-key"
+        assert "base_url" not in result