diff --git a/src/wandbot/api/app.py b/src/wandbot/api/app.py
index cdc6e54..d815372 100644
--- a/src/wandbot/api/app.py
+++ b/src/wandbot/api/app.py
@@ -35,12 +35,14 @@
 
 import pandas as pd
 import weave
-from fastapi import FastAPI
+from fastapi import BackgroundTasks, FastAPI
 
 import wandb
 from wandbot.api.routers import chat as chat_router
 from wandbot.api.routers import database as database_router
 from wandbot.api.routers import retrieve as retrieve_router
+from wandbot.database.database import engine
+from wandbot.database.models import Base
 from wandbot.ingestion.config import VectorStoreConfig
 from wandbot.retriever import VectorStore
 from wandbot.utils import get_logger
@@ -50,6 +52,20 @@
 
 weave.init(f"{os.environ['WANDB_ENTITY']}/{os.environ['WANDB_PROJECT']}")
 
+is_initialized = False
+
+
+async def initialize():
+    global is_initialized
+    if not is_initialized:
+        vector_store = VectorStore.from_config(VectorStoreConfig())
+        chat_router.chat = chat_router.Chat(vector_store=vector_store)
+        database_router.db_client = database_router.DatabaseClient()
+        retrieve_router.retriever = retrieve_router.SimpleRetrievalEngine(
+            vector_store=vector_store
+        )
+        is_initialized = True
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
@@ -61,12 +77,8 @@ async def lifespan(app: FastAPI):
     Returns:
         None
     """
-    vector_store = VectorStore.from_config(VectorStoreConfig())
-    chat_router.chat = chat_router.Chat(vector_store=vector_store)
-    database_router.db_client = database_router.DatabaseClient()
-    retrieve_router.retriever = retrieve_router.SimpleRetrievalEngine(
-        vector_store=vector_store
-    )
+
+    Base.metadata.create_all(bind=engine)
 
     async def backup_db():
         """Periodically backs up the database to a table.
@@ -107,11 +119,16 @@ async def backup_db():
 )
 
 
+@app.get("/")
+async def root(background_tasks: BackgroundTasks):
+    background_tasks.add_task(initialize)
+    return {"message": "Initialization started in the background"}
+
+
 app.include_router(chat_router.router)
 app.include_router(database_router.router)
 app.include_router(retrieve_router.router)
 
-
 if __name__ == "__main__":
     import uvicorn
 
diff --git a/src/wandbot/apps/utils.py b/src/wandbot/apps/utils.py
index d75f249..59d99f4 100644
--- a/src/wandbot/apps/utils.py
+++ b/src/wandbot/apps/utils.py
@@ -62,7 +62,7 @@ def format_response(
             sources_list = deduplicate(
                 [
                     item
-                    for item in response.sources.split(",")
+                    for item in response.sources.split("\n")
                     if item.strip().startswith("http")
                 ]
             )
@@ -72,13 +72,13 @@ def format_response(
                     result = (
                         f"{result}\n\n*参考文献*\n\n>"
                         + "\n> ".join(sources_list[:items])
-                        + "\n\n"
+                        + "\n"
                     )
                 else:
                     result = (
                         f"{result}\n\n*References*\n\n>"
                         + "\n> ".join(sources_list[:items])
-                        + "\n\n"
+                        + "\n"
                     )
         if outro_message:
             result = f"{result}\n\n{outro_message}"
diff --git a/src/wandbot/database/database.py b/src/wandbot/database/database.py
index 2647e68..0ed0a93 100644
--- a/src/wandbot/database/database.py
+++ b/src/wandbot/database/database.py
@@ -14,7 +14,6 @@
 from sqlalchemy.orm import sessionmaker
 
 from wandbot.database.config import DataBaseConfig
-from wandbot.database.models import Base
 
 db_config = DataBaseConfig()
 
@@ -22,4 +21,3 @@
     db_config.SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
 )
 SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
-Base.metadata.create_all(bind=engine)