address CI: reduce C901 complexity, fix TypedDict test access

- Extract two helpers from load_vector_stores_from_config:
  _build_managed_vector_store_from_config_entry (per-entry construction
  + required-param validation) and _drop_config_entries_removed_from_new_config
  (stale marker eviction). Puts the main method back under the C901
  strict-budget limit (was +1 over).
- Endpoint test: LiteLLM_ManagedVectorStoreListResponse is a TypedDict;
  use dict-style access on the response body instead of attribute access.

litellm/vector_stores/vector_store_registry.py

@@ -93,6 +93,40 @@ class VectorStoreIndexRegistry:
         return vector_stores_from_db
 
 
+def _build_managed_vector_store_from_config_entry(vector_store_config: dict) -> LiteLLM_ManagedVectorStore:
+    """Construct a LiteLLM_ManagedVectorStore from one config.yaml entry.
+
+    Extracted from load_vector_stores_from_config to keep that method under the
+    C901 complexity budget; also enforces the two required params (vector_store_id
+    and custom_llm_provider) in one place with clear error messages.
+    """
+    litellm_vector_store_config = LiteLLM_VectorStoreConfig(**vector_store_config)
+    vector_store_name = litellm_vector_store_config.get("vector_store_name")
+    vector_store_litellm_params: dict[str, Any] = litellm_vector_store_config.get("litellm_params") or {}
+
+    vector_store_id = vector_store_litellm_params.get("vector_store_id")
+    if vector_store_id is None:
+        raise ValueError(
+            f"vector_store_id is required for initializing vector store, got vector_store_id={vector_store_id}"
+        )
+    custom_llm_provider = vector_store_litellm_params.get("custom_llm_provider")
+    if custom_llm_provider is None:
+        raise ValueError(
+            f"custom_llm_provider is required for initializing vector store, got custom_llm_provider={custom_llm_provider}"
+        )
+
+    return LiteLLM_ManagedVectorStore(
+        vector_store_id=vector_store_id,
+        custom_llm_provider=custom_llm_provider,
+        litellm_params=vector_store_litellm_params,
+        vector_store_name=vector_store_name,
+        vector_store_description=vector_store_litellm_params.get("vector_store_description"),
+        vector_store_metadata=vector_store_litellm_params.get("vector_store_metadata"),
+        created_at=datetime.now(timezone.utc),
+        updated_at=datetime.now(timezone.utc),
+    )
+
+
 class VectorStoreRegistry:
     def __init__(self, vector_stores: list[LiteLLM_ManagedVectorStore] | None = None):
         # Never bind a mutable default: the previous `= []` default caused every
@@ -394,6 +428,14 @@ class VectorStoreRegistry:
                     vector_store_ids.extend(tool["vector_store_ids"])
         return vector_store_ids
 
+    def _drop_config_entries_removed_from_new_config(self, new_config_ids: set[str]) -> None:
+        """Evict any previously-config-loaded store whose id isn't in the new config,
+        so config removals stop being protected from list-endpoint reconciliation."""
+        for stale_id in self.config_loaded_vector_store_ids - new_config_ids:
+            # delete_vector_store_from_registry also discards from
+            # config_loaded_vector_store_ids, keeping the two in sync.
+            self.delete_vector_store_from_registry(stale_id)
+
     def load_vector_stores_from_config(self, vector_stores_config: list[dict]):
         """
         Loads vector stores from the litellm proxy config.yaml.
@@ -407,44 +449,14 @@ class VectorStoreRegistry:
             (cfg.get("litellm_params") or {}).get("vector_store_id") for cfg in vector_stores_config
         }
         new_config_ids.discard(None)  # ids missing here will re-raise below with a clearer error
-
-        stale_ids: Final = self.config_loaded_vector_store_ids - new_config_ids
-        for stale_id in stale_ids:
-            # delete_vector_store_from_registry also discards from
-            # config_loaded_vector_store_ids, keeping the two in sync.
-            self.delete_vector_store_from_registry(stale_id)
+        self._drop_config_entries_removed_from_new_config(new_config_ids)
 
         for vector_store_config in vector_stores_config:
-            # cast to VectorStoreConfig
-            litellm_vector_store_config = LiteLLM_VectorStoreConfig(**vector_store_config)
-            vector_store_name = litellm_vector_store_config.get("vector_store_name")
-            vector_store_litellm_params: dict[str, Any] = litellm_vector_store_config.get("litellm_params") or {}
-
-            vector_store_id = vector_store_litellm_params.get("vector_store_id")
-            if vector_store_id is None:
-                raise ValueError(
-                    f"vector_store_id is required for initializing vector store, got vector_store_id={vector_store_id}"
-                )
-            custom_llm_provider = vector_store_litellm_params.get("custom_llm_provider")
-            if custom_llm_provider is None:
-                raise ValueError(
-                    f"custom_llm_provider is required for initializing vector store, got custom_llm_provider={custom_llm_provider}"
-                )
-
-            litellm_managed_vector_store = LiteLLM_ManagedVectorStore(
-                vector_store_id=vector_store_id,
-                custom_llm_provider=custom_llm_provider,
-                litellm_params=vector_store_litellm_params,
-                vector_store_name=vector_store_name,
-                vector_store_description=vector_store_litellm_params.get("vector_store_description"),
-                vector_store_metadata=vector_store_litellm_params.get("vector_store_metadata"),
-                created_at=datetime.now(timezone.utc),
-                updated_at=datetime.now(timezone.utc),
-            )
+            managed = _build_managed_vector_store_from_config_entry(vector_store_config)
             # add_vector_store_to_registry is idempotent by id, so a reload
             # that re-lists an existing store won't create duplicates.
-            self.add_vector_store_to_registry(litellm_managed_vector_store)
-            self.config_loaded_vector_store_ids.add(vector_store_id)
+            self.add_vector_store_to_registry(managed)
+            self.config_loaded_vector_store_ids.add(managed["vector_store_id"])
 
         verbose_logger.debug(
             "all loaded vector stores = %s",

tests/test_litellm/proxy/vector_store_endpoints/test_vector_store_endpoints.py

@@ -3162,7 +3162,9 @@ async def test_list_vector_stores_returns_config_sourced_and_leaves_registry_int
                 ),
             )
 
-        returned_ids = [vs["vector_store_id"] for vs in response.data]
+        # LiteLLM_ManagedVectorStoreListResponse is a TypedDict — use dict access.
+        response_data = response["data"] if isinstance(response, dict) else response.data
+        returned_ids = [vs["vector_store_id"] for vs in response_data]
         assert "vs_from_config" in returned_ids
         # And, critically, the registry must NOT have been mutated —
         # config-loaded stores stay resident for downstream routing.