fix(router.py): support reusable credentials via passthrough router (#9758)

* fix(router.py): support reusable credentials via passthrough router

enables reusable vertex credentials to be used in passthrough

* test: fix test

* test(test_router_adding_deployments.py): add unit testing

litellm/litellm_core_utils/credential_accessor.py

@@ -10,6 +10,7 @@ class CredentialAccessor:
     @staticmethod
     def get_credential_values(credential_name: str) -> dict:
         """Safe accessor for credentials."""
+
         if not litellm.credential_list:
             return {}
         for credential in litellm.credential_list:

litellm/router.py

@@ -54,6 +54,7 @@ from litellm.constants import DEFAULT_MAX_LRU_CACHE_SIZE
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.litellm_core_utils.asyncify import run_async_function
 from litellm.litellm_core_utils.core_helpers import _get_parent_otel_span_from_kwargs
+from litellm.litellm_core_utils.credential_accessor import CredentialAccessor
 from litellm.litellm_core_utils.dd_tracing import tracer
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLogging
 from litellm.router_strategy.budget_limiter import RouterBudgetLimiting
@@ -4506,25 +4507,53 @@ class Router:
                 passthrough_endpoint_router,
             )
 
+            if deployment.litellm_params.litellm_credential_name is not None:
+                credential_values = CredentialAccessor.get_credential_values(
+                    deployment.litellm_params.litellm_credential_name
+                )
+            else:
+                credential_values = {}
+
             if custom_llm_provider == "vertex_ai":
+                vertex_project = (
+                    credential_values.get("vertex_project")
+                    or deployment.litellm_params.vertex_project
+                )
+                vertex_location = (
+                    credential_values.get("vertex_location")
+                    or deployment.litellm_params.vertex_location
+                )
+                vertex_credentials = (
+                    credential_values.get("vertex_credentials")
+                    or deployment.litellm_params.vertex_credentials
+                )
+
                 if (
-                    deployment.litellm_params.vertex_project is None
-                    or deployment.litellm_params.vertex_location is None
-                    or deployment.litellm_params.vertex_credentials is None
+                    vertex_project is None
+                    or vertex_location is None
+                    or vertex_credentials is None
                 ):
                     raise ValueError(
                         "vertex_project, vertex_location, and vertex_credentials must be set in litellm_params for pass-through endpoints"
                     )
                 passthrough_endpoint_router.add_vertex_credentials(
-                    project_id=deployment.litellm_params.vertex_project,
-                    location=deployment.litellm_params.vertex_location,
-                    vertex_credentials=deployment.litellm_params.vertex_credentials,
+                    project_id=vertex_project,
+                    location=vertex_location,
+                    vertex_credentials=vertex_credentials,
                 )
             else:
+                api_base = (
+                    credential_values.get("api_base")
+                    or deployment.litellm_params.api_base
+                )
+                api_key = (
+                    credential_values.get("api_key")
+                    or deployment.litellm_params.api_key
+                )
                 passthrough_endpoint_router.set_pass_through_credentials(
                     custom_llm_provider=custom_llm_provider,
-                    api_base=deployment.litellm_params.api_base,
-                    api_key=deployment.litellm_params.api_key,
+                    api_base=api_base,
+                    api_key=api_key,
                 )
             pass
         pass

litellm/types/router.py

@@ -179,6 +179,7 @@ class GenericLiteLLMParams(CredentialLiteLLMParams):
     max_retries: Optional[int] = None
     organization: Optional[str] = None  # for openai orgs
     configurable_clientside_auth_params: CONFIGURABLE_CLIENTSIDE_AUTH_PARAMS = None
+    litellm_credential_name: Optional[str] = None
 
     ## LOGGING PARAMS ##
     litellm_trace_id: Optional[str] = None

tests/router_unit_tests/test_router_adding_deployments.py

@@ -9,23 +9,48 @@ from litellm.router import Deployment, LiteLLM_Params
 from unittest.mock import patch
 import json
 
-
-def test_initialize_deployment_for_pass_through_success():
+@pytest.mark.parametrize("reusable_credentials", [True, False])
+def test_initialize_deployment_for_pass_through_success(reusable_credentials):
     """
     Test successful initialization of a Vertex AI pass-through deployment
     """
+    from litellm.litellm_core_utils.credential_accessor import CredentialAccessor
+    from litellm.types.utils import CredentialItem
+
+    vertex_project="test-project"
+    vertex_location="us-central1"
+    vertex_credentials=json.dumps({"type": "service_account", "project_id": "test"})
+
+    if not reusable_credentials:
+        litellm_params = LiteLLM_Params(
+            model="vertex_ai/test-model",
+            vertex_project=vertex_project,
+            vertex_location=vertex_location,
+            vertex_credentials=vertex_credentials,
+            use_in_pass_through=True,
+        )
+    else:
+        # add credentials to the credential accessor
+        CredentialAccessor.upsert_credentials([
+            CredentialItem(
+                credential_name="vertex_credentials",
+                credential_values={
+                    "vertex_project": vertex_project,
+                    "vertex_location": vertex_location,
+                    "vertex_credentials": vertex_credentials,
+                },
+                credential_info={}
+            )
+        ])
+        litellm_params = LiteLLM_Params(
+            model="vertex_ai/test-model",
+            litellm_credential_name="vertex_credentials",
+            use_in_pass_through=True,
+        )
     router = Router(model_list=[])
     deployment = Deployment(
         model_name="vertex-test",
-        litellm_params=LiteLLM_Params(
-            model="vertex_ai/test-model",
-            vertex_project="test-project",
-            vertex_location="us-central1",
-            vertex_credentials=json.dumps(
-                {"type": "service_account", "project_id": "test"}
-            ),
-            use_in_pass_through=True,
-        ),
+        litellm_params=litellm_params,
     )
 
     # Test the initialization