diff --git a/backend/config.py b/backend/config.py
index dd3bc9e4b..098de3b5a 100644
--- a/backend/config.py
+++ b/backend/config.py
@@ -852,6 +852,12 @@ SERPER_API_KEY = PersistentConfig(
     os.getenv("SERPER_API_KEY", ""),
 )
 
+SERPLY_API_KEY = PersistentConfig(
+    "SERPLY_API_KEY",
+    "rag.web.search.serply_api_key",
+    os.getenv("SERPLY_API_KEY", ""),
+)
+
 
 RAG_WEB_SEARCH_RESULT_COUNT = PersistentConfig(
     "RAG_WEB_SEARCH_RESULT_COUNT",