fix(vllm): forward api key for model discovery

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/llms/vllm/common_utils.py

@@ -63,8 +63,13 @@ class VLLMModelInfo(BaseLLMModelInfo):
         endpoint: Final = "/v1/models"
 
         url: Final = _add_path_to_api_base(api_base, endpoint)
-        response: Final = litellm.module_level_client.get(
-            url=url,
+        response: Final = (
+            litellm.module_level_client.get(
+                url=url,
+                headers={"x-api-key": api_key},  # mutable-ok: optional authentication header
+            )
+            if api_key is not None
+            else litellm.module_level_client.get(url=url)
         )
 
         response.raise_for_status()

tests/test_litellm/proxy/auth/test_model_checks.py

@@ -465,6 +465,34 @@ def test_get_known_models_from_wildcard_hosted_vllm_uses_provider_endpoint():
     ]
 
 
+def test_get_known_models_from_wildcard_hosted_vllm_forwards_api_key():
+    import litellm
+    from litellm.proxy.auth.model_checks import get_known_models_from_wildcard
+    from litellm.types.router import LiteLLM_Params
+
+    response = MagicMock()
+    response.json.return_value = {"data": [{"id": "qwen2.5"}]}
+    original_check_provider_endpoint = litellm.check_provider_endpoint
+    try:
+        litellm.check_provider_endpoint = True  # test-quality-ok: required to exercise provider endpoint discovery
+        with patch(  # test-quality-ok: required HTTP boundary
+            "litellm.module_level_client.get", return_value=response
+        ) as mock_get:
+            result = get_known_models_from_wildcard(
+                "hosted_vllm/*",
+                LiteLLM_Params(
+                    model="hosted_vllm/*",
+                    api_base="http://localhost:8000/v1",
+                    api_key="test-key",
+                ),
+            )
+    finally:
+        litellm.check_provider_endpoint = original_check_provider_endpoint  # test-quality-ok: restore test global
+
+    assert result == ["hosted_vllm/qwen2.5"]
+    assert mock_get.call_args.kwargs["headers"] == {"x-api-key": "test-key"}
+
+
 def test_get_known_models_from_wildcard_unknown_provider_returns_empty():
     from litellm.proxy.auth.model_checks import get_known_models_from_wildcard