feat(azure/passthrough): working azure passthrough with router models for openai calls

Fixes issue where azure passthrough could not work with workload identity + litellm model name

litellm/llms/azure/common_utils.py

@@ -665,10 +665,6 @@ class BaseAzureLLM(BaseOpenAILLM):
     ) -> dict:
         litellm_params = litellm_params or GenericLiteLLMParams()
 
-        # If api-key is already in headers, preserve it
-        if "api-key" in headers:
-            return headers
-
         api_key = (
             litellm_params.api_key
             or litellm.api_key

litellm/llms/azure/passthrough/transformation.py

@@ -58,7 +58,9 @@ class AzurePassthroughConfig(BasePassthroughConfig):
     ) -> dict:
         return BaseAzureLLM._base_validate_azure_environment(
             headers=headers,
-            litellm_params=GenericLiteLLMParams(**litellm_params),
+            litellm_params=GenericLiteLLMParams(
+                **{**litellm_params, "api_key": api_key}
+            ),
         )
 
     @staticmethod

litellm/proxy/_new_secret_config.yaml

@@ -20,7 +20,7 @@ model_list:
       model: azure/gpt-4.1
       api_base: os.environ/AZURE_API_BASE_ALT
       api_version: "2023-05-15"
-      api_key: os.environ/AZURE_API_KEY_HIDDEN
+      api_key: os.environ/AZURE_API_KEY_ALT
 
 # mcp_servers:
 #   github_mcp: