Add support for extra headers in Claude SDK API (#2445)

Third-party model providers offering Claude services require additional dynamic header information.

Co-authored-by: ssiq <liweiwuhome@hotmail.com>

Author: SongYippee

opencompass/models/claude_sdk_api.py

@@ -39,6 +39,8 @@ class ClaudeSDK(BaseAPIModel):
             wrapping of any meta instructions.
         base_url (str, optional): Anthropic-compatible base URL. If omitted,
             use ANTHROPIC_BASE_URL from environment.
+        extra_headers (Dict, optional): Extra default HTTP headers passed to
+            the Anthropic SDK client.
         stream (bool): Whether to use streaming response. Defaults to False.
         retry (int): Number of retires if the API call fails. Defaults to 2.
         think_tag (str): Separator used between thinking content and final
@@ -59,6 +61,7 @@ def __init__(
         base_url: Optional[str] = None,
         stream: bool = False,
         retry: int = 2,
+        extra_headers: Optional[Dict[str, str]] = None,
         think_tag: str = '</think>',
         claude_extra_kwargs: Optional[Dict] = None,
     ):
@@ -83,6 +86,8 @@ def __init__(
         client_kwargs = {'api_key': key}
         if base_url:
             client_kwargs['base_url'] = base_url
+        if extra_headers is not None:
+            client_kwargs['default_headers'] = extra_headers
 
         self.anthropic = Anthropic(**client_kwargs)
         self.model = path

tests/models/test_claude_sdk_api.py

@@ -42,6 +42,21 @@ def test_anthropic_base_url_env_is_used_as_is(self):
             api_key='test-key', base_url='https://proxy.example/v1')
         self.assertEqual(model.base_url, 'https://proxy.example/v1')
 
+    @patch.dict('os.environ', {}, clear=True)
+    def test_extra_headers_are_passed_to_client(self):
+        """Test extra_headers are passed to the Anthropic SDK client."""
+        headers = {
+            'anthropic-beta': 'prompt-caching-2024-07-31',
+            'x-provider-region': 'test-region',
+        }
+        _, anthropic_cls, _ = self.build_model(
+            base_url='https://proxy.example/v1', extra_headers=headers)
+
+        anthropic_cls.assert_called_once_with(
+            api_key='test-key',
+            base_url='https://proxy.example/v1',
+            default_headers=headers)
+
     @patch.dict('os.environ',
                 {
                     'ANTHROPIC_API_KEY': 'env-key',