[Fix] Forward anthropic-beta headers to Bedrock and other anthropic providers

litellm/litellm_core_utils/get_provider_specific_headers.py

@@ -10,14 +10,20 @@ def get_provider_specific_headers(
         custom_llm_provider: Optional[str],
     ) -> Dict:
         """
-        Get the provider specific headers for the given custom llm provider
+        Get the provider specific headers for the given custom llm provider.
+
+        Supports comma-separated provider lists for headers that work across multiple providers.
 
         Returns:
-            Optional[Dict]: The provider specific headers for the given custom llm provider
+            Dict: The provider specific headers for the given custom llm provider
         """
-        if (
-            provider_specific_header is not None
-            and provider_specific_header.get("custom_llm_provider") == custom_llm_provider
-        ):
+        if provider_specific_header is None or custom_llm_provider is None:
+            return {}
+
+        stored_providers = provider_specific_header.get("custom_llm_provider", "")
+        provider_list = [p.strip() for p in stored_providers.split(",")]
+
+        if custom_llm_provider in provider_list:
             return provider_specific_header.get("extra_headers", {})
-        return {}
+
+        return {}

litellm/proxy/litellm_pre_call_utils.py

@@ -1252,8 +1252,10 @@ def add_provider_specific_headers_to_request(
             added_header = True
 
     if added_header is True:
+        # Anthropic headers work across multiple providers
+        # Store as comma-separated list so retrieval can match any of them
         data["provider_specific_header"] = ProviderSpecificHeader(
-            custom_llm_provider="anthropic",
+            custom_llm_provider="anthropic,bedrock,bedrock_converse,vertex_ai",
             extra_headers=anthropic_headers,
         )