[fix] extra_headers in messages api bedrock invoke

litellm/llms/custom_httpx/llm_http_handler.py

@@ -1804,15 +1804,21 @@ async def async_anthropic_messages_handler(
             Optional[litellm.types.utils.ProviderSpecificHeader],
             kwargs.get("provider_specific_header", None),
         )
-        extra_headers = ProviderSpecificHeaderUtils.get_provider_specific_headers(
+        provider_specific_headers = ProviderSpecificHeaderUtils.get_provider_specific_headers(
             provider_specific_header=provider_specific_header,
             custom_llm_provider=custom_llm_provider,
         )
         forwarded_headers = kwargs.get("headers", None)
-        if forwarded_headers and extra_headers:
-            merged_headers = {**forwarded_headers, **extra_headers}
-        else:
-            merged_headers = forwarded_headers or extra_headers
+        # Also check for extra_headers in kwargs (from config or direct calls)
+        extra_headers_from_kwargs = kwargs.get("extra_headers", None)
+        # Merge all header sources: forwarded < extra_headers < provider_specific
+        merged_headers = {}
+        if forwarded_headers:
+            merged_headers.update(forwarded_headers)
+        if extra_headers_from_kwargs:
+            merged_headers.update(extra_headers_from_kwargs)
+        if provider_specific_headers:
+            merged_headers.update(provider_specific_headers)
         (
             headers,
             api_base,

tests/test_litellm/llms/bedrock/test_anthropic_beta_support.py

@@ -80,7 +80,8 @@ def test_converse_transformation_anthropic_beta(self):
         assert "additionalModelRequestFields" in result
         additional_fields = result["additionalModelRequestFields"]
         assert "anthropic_beta" in additional_fields
-        assert additional_fields["anthropic_beta"] == ["context-1m-2025-08-07", "interleaved-thinking-2025-05-14"]
+        # Sort both arrays before comparing to avoid flakiness from ordering differences
+        assert sorted(additional_fields["anthropic_beta"]) == sorted(["context-1m-2025-08-07", "interleaved-thinking-2025-05-14"])
 
     def test_messages_transformation_anthropic_beta(self):
         """Test that Messages API transformation includes anthropic_beta in request."""
@@ -96,7 +97,8 @@ def test_messages_transformation_anthropic_beta(self):
         )
 
         assert "anthropic_beta" in result
-        assert result["anthropic_beta"] == ["output-128k-2025-02-19"]
+        # Sort both arrays before comparing to avoid flakiness from ordering differences
+        assert sorted(result["anthropic_beta"]) == sorted(["output-128k-2025-02-19"])
 
     def test_converse_computer_use_compatibility(self):
         """Test that user anthropic_beta headers work with computer use tools."""
@@ -287,4 +289,4 @@ def test_prompt_caching_with_other_beta_headers(self):
             assert "prompt-caching-2024-07-31" not in result["anthropic_beta"]
         else:
             # If no beta headers, that's also fine
-            assert True
+            assert True

tests/test_litellm/llms/custom_httpx/test_llm_http_handler.py

@@ -1,17 +1,14 @@
-import io
 import os
-import pathlib
-import ssl
 import sys
-from unittest.mock import MagicMock
+from unittest.mock import AsyncMock, Mock, patch
 
 import pytest
 
 sys.path.insert(
     0, os.path.abspath("../../../..")
 )  # Adds the parent directory to the system path
-import litellm
 from litellm.llms.custom_httpx.llm_http_handler import BaseLLMHTTPHandler
+from litellm.types.router import GenericLiteLLMParams
 
 
 def test_prepare_fake_stream_request():
@@ -75,3 +72,146 @@ def test_prepare_fake_stream_request():
     assert "stream" not in result_data
     assert result_data["model"] == "gpt-4"
     assert result_data["messages"] == [{"role": "user", "content": "Hello"}]
+
+
+@pytest.mark.asyncio
+async def test_async_anthropic_messages_handler_extra_headers():
+    """
+    Test that async_anthropic_messages_handler correctly extracts and merges
+    extra_headers from kwargs with proper priority.
+    """
+    handler = BaseLLMHTTPHandler()
+
+    # Mock the config
+    mock_config = Mock()
+    mock_config.validate_anthropic_messages_environment = Mock(
+        return_value=({"x-api-key": "test-key"}, "https://api.anthropic.com")
+    )
+    mock_config.transform_anthropic_messages_request = Mock(
+        return_value={"model": "claude-3-opus-20240229", "messages": []}
+    )
+
+    # Mock the client
+    mock_client = AsyncMock()
+    mock_response = Mock()
+    mock_response.status_code = 200
+    mock_response.json.return_value = {
+        "id": "msg_123",
+        "type": "message",
+        "role": "assistant",
+        "content": [{"type": "text", "text": "Hello!"}],
+        "model": "claude-3-opus-20240229",
+        "stop_reason": "end_turn",
+    }
+    mock_client.post = AsyncMock(return_value=mock_response)
+
+    # Mock logging object
+    mock_logging_obj = Mock()
+    mock_logging_obj.update_environment_variables = Mock()
+    mock_logging_obj.model_call_details = {}
+    mock_logging_obj.stream = False
+
+    # Test case 1: Only extra_headers in kwargs
+    kwargs = {
+        "extra_headers": {
+            "X-Custom-Header": "from-kwargs",
+            "X-Auth-Token": "token123",
+        }
+    }
+
+    with patch(
+        "litellm.litellm_core_utils.get_provider_specific_headers.ProviderSpecificHeaderUtils.get_provider_specific_headers"
+    ) as mock_provider_headers:
+        mock_provider_headers.return_value = None
+
+        # Capture what headers are passed to validate_anthropic_messages_environment
+        captured_headers = {}
+        def capture_validate(*args, **kwargs):
+            captured_headers.update(kwargs.get("headers", {}))
+            return ({"x-api-key": "test-key"}, "https://api.anthropic.com")
+
+        mock_config.validate_anthropic_messages_environment = capture_validate
+
+        try:
+            await handler.async_anthropic_messages_handler(
+                model="claude-3-opus-20240229",
+                messages=[{"role": "user", "content": "Hello"}],
+                anthropic_messages_provider_config=mock_config,
+                anthropic_messages_optional_request_params={},
+                custom_llm_provider="anthropic",
+                litellm_params=GenericLiteLLMParams(),
+                logging_obj=mock_logging_obj,
+                client=mock_client,
+                kwargs=kwargs,
+            )
+        except Exception:
+            pass  # We're testing header extraction, not the full flow
+
+        # Verify extra_headers were extracted and merged
+        assert "X-Custom-Header" in captured_headers
+        assert captured_headers["X-Custom-Header"] == "from-kwargs"
+        assert "X-Auth-Token" in captured_headers
+        assert captured_headers["X-Auth-Token"] == "token123"
+
+
+@pytest.mark.asyncio
+async def test_async_anthropic_messages_handler_header_priority():
+    """
+    Test that async_anthropic_messages_handler respects header priority:
+    forwarded < extra_headers < provider_specific
+    """
+    handler = BaseLLMHTTPHandler()
+
+    # Mock the config
+    mock_config = Mock()
+    mock_client = AsyncMock()
+    mock_logging_obj = Mock()
+    mock_logging_obj.update_environment_variables = Mock()
+    mock_logging_obj.model_call_details = {}
+    mock_logging_obj.stream = False
+
+    # Test with all three header sources
+    kwargs = {
+        "headers": {"X-Priority": "forwarded", "X-Forwarded-Only": "keep"},
+        "extra_headers": {"X-Priority": "extra", "X-Extra-Only": "also-keep"},
+    }
+
+    with patch(
+        "litellm.litellm_core_utils.get_provider_specific_headers.ProviderSpecificHeaderUtils.get_provider_specific_headers"
+    ) as mock_provider_headers:
+        mock_provider_headers.return_value = {
+            "X-Priority": "provider",
+            "X-Provider-Only": "keep-this-too"
+        }
+
+        captured_headers = {}
+        def capture_validate(*args, **kwargs):
+            captured_headers.update(kwargs.get("headers", {}))
+            return ({"x-api-key": "test-key"}, "https://api.anthropic.com")
+
+        mock_config.validate_anthropic_messages_environment = capture_validate
+        mock_config.transform_anthropic_messages_request = Mock(
+            return_value={"model": "claude-3-opus-20240229", "messages": []}
+        )
+
+        try:
+            await handler.async_anthropic_messages_handler(
+                model="claude-3-opus-20240229",
+                messages=[{"role": "user", "content": "Hello"}],
+                anthropic_messages_provider_config=mock_config,
+                anthropic_messages_optional_request_params={},
+                custom_llm_provider="anthropic",
+                litellm_params=GenericLiteLLMParams(),
+                logging_obj=mock_logging_obj,
+                client=mock_client,
+                kwargs=kwargs,
+            )
+        except Exception:
+            pass
+
+        # Verify priority: provider_specific should win
+        assert captured_headers["X-Priority"] == "provider"
+        # Verify all unique headers from different sources are present
+        assert captured_headers["X-Forwarded-Only"] == "keep"
+        assert captured_headers["X-Extra-Only"] == "also-keep"
+        assert captured_headers["X-Provider-Only"] == "keep-this-too"