diff --git a/api/core/rag/datasource/vdb/vector_base.py b/api/core/rag/datasource/vdb/vector_base.py
index 469978224a..acf3465c5f 100644
--- a/api/core/rag/datasource/vdb/vector_base.py
+++ b/api/core/rag/datasource/vdb/vector_base.py
@@ -15,7 +15,7 @@ class BaseVector(ABC):
         raise NotImplementedError
 
     @abstractmethod
-    def create(self, texts: list[Document], embeddings: list[list[float]], **kwargs):
+    def create(self, texts: list[Document], embeddings: list[list[float]], **kwargs) -> list[str] | None:
         raise NotImplementedError
 
     @abstractmethod