fix(vector_store): /list preserves config-sourced entries

Track config-loaded vector store IDs on VectorStoreRegistry and exempt
them from the "in memory but not in DB → deleted" reconciliation in
GET /vector_store/list. Previously, any store declared in config.yaml /
kustomization was invisible in the UI AND silently evicted from the
running registry on every list call, breaking downstream routing until
the next config reload.

Fixes #38258

litellm/proxy/vector_store_endpoints/management_endpoints.py

@@ -623,6 +623,10 @@ async def list_vector_stores(
         # Process in-memory vector stores
         if litellm.vector_store_registry is not None:
             in_memory_vector_stores: Final = copy.deepcopy(litellm.vector_store_registry.vector_stores)
+            # Vector stores loaded from config.yaml have no DB row; they must be
+            # returned alongside DB-sourced entries and MUST NOT be pruned by the
+            # "in memory but not in DB → deleted" reconciliation below.
+            config_loaded_ids: Final = litellm.vector_store_registry.config_loaded_vector_store_ids
 
             vector_stores_to_delete_from_memory: Final[list[str]] = []
 
@@ -631,6 +635,13 @@ async def list_vector_stores(
                 if not vector_store_id:
                     continue
 
+                # Config-loaded stores: surface them in the response but never
+                # treat them as "deleted from DB" — they never had a DB row.
+                if vector_store_id in config_loaded_ids:
+                    if vector_store_id not in vector_store_map:
+                        vector_store_map[vector_store_id] = vector_store
+                    continue
+
                 # If vector store is in memory but NOT in database, it was deleted
                 if vector_store_id not in db_vector_store_ids:
                     verbose_proxy_logger.info(

litellm/vector_stores/vector_store_registry.py

@@ -97,6 +97,10 @@ class VectorStoreRegistry:
     def __init__(self, vector_stores: list[LiteLLM_ManagedVectorStore] = []):
         self.vector_stores: list[LiteLLM_ManagedVectorStore] = vector_stores
         self.vector_store_ids_to_vector_store_map: dict[str, LiteLLM_ManagedVectorStore] = {}
+        # IDs of vector stores that were loaded from config.yaml / kustomization.
+        # These have no DB row, so reconciliation code paths that treat "in memory
+        # but not in DB" as "was deleted" must exempt them.
+        self.config_loaded_vector_store_ids: set[str] = set()
 
     def _extract_tool_params(self, tool: dict) -> VectorStoreToolParams:
         """
@@ -418,6 +422,7 @@ class VectorStoreRegistry:
                 updated_at=datetime.now(timezone.utc),
             )
             self.vector_stores.append(litellm_managed_vector_store)
+            self.config_loaded_vector_store_ids.add(vector_store_id)
 
         verbose_logger.debug(
             "all loaded vector stores = %s",
@@ -463,6 +468,9 @@ class VectorStoreRegistry:
             for vector_store in self.vector_stores
             if vector_store.get("vector_store_id") != vector_store_id
         ]
+        # If this was a config-loaded id, drop the marker so it can be re-loaded
+        # cleanly on next config reload without being incorrectly protected.
+        self.config_loaded_vector_store_ids.discard(vector_store_id)
 
     def update_vector_store_in_registry(self, vector_store_id: str, updated_data: LiteLLM_ManagedVectorStore):
         """Update or add a vector store in the registry"""

tests/vector_store_tests/test_config_loaded_vector_stores.py

@@ -0,0 +1,57 @@
+"""
+Tests for the config-sourced vector store fix.
+
+Regression: `/vector_store/list` used to prune config.yaml-loaded stores from
+the in-memory registry because they have no DB row. The fix tracks
+`config_loaded_vector_store_ids` on the registry and exempts them from the
+"in memory but not in DB" reconciliation branch.
+"""
+from litellm.vector_stores.vector_store_registry import VectorStoreRegistry
+
+
+def _config_entry(vs_id: str) -> dict:
+    return {
+        "vector_store_name": f"name-{vs_id}",
+        "litellm_params": {
+            "vector_store_id": vs_id,
+            "custom_llm_provider": "bedrock",
+        },
+    }
+
+
+def test_load_from_config_tracks_id():
+    registry = VectorStoreRegistry()
+    assert registry.config_loaded_vector_store_ids == set()
+
+    registry.load_vector_stores_from_config([_config_entry("vs_a"), _config_entry("vs_b")])
+
+    assert {vs["vector_store_id"] for vs in registry.vector_stores} == {"vs_a", "vs_b"}
+    assert registry.config_loaded_vector_store_ids == {"vs_a", "vs_b"}
+
+
+def test_delete_drops_config_marker():
+    """After a config-loaded store is explicitly deleted, the marker must go
+    with it so a later reload can re-create the entry without confusion."""
+    registry = VectorStoreRegistry()
+    registry.load_vector_stores_from_config([_config_entry("vs_a")])
+    assert "vs_a" in registry.config_loaded_vector_store_ids
+
+    registry.delete_vector_store_from_registry("vs_a")
+
+    assert registry.vector_stores == []
+    assert "vs_a" not in registry.config_loaded_vector_store_ids
+
+
+def test_delete_of_db_only_store_does_not_touch_marker_set():
+    registry = VectorStoreRegistry()
+    registry.load_vector_stores_from_config([_config_entry("vs_config")])
+    # Simulate a DB-sourced entry being added via /vector_store/new
+    registry.add_vector_store_to_registry(
+        {"vector_store_id": "vs_from_db", "custom_llm_provider": "openai"}
+    )
+
+    registry.delete_vector_store_from_registry("vs_from_db")
+
+    assert [vs["vector_store_id"] for vs in registry.vector_stores] == ["vs_config"]
+    # Config marker for the untouched entry is intact.
+    assert registry.config_loaded_vector_store_ids == {"vs_config"}