moving init of semantic_rag_chain to start()

app.py

@@ -8,6 +8,7 @@ _logger.addHandler(logging.StreamHandler(stream=sys.stdout))
 
 from langchain_core.prompts import ChatPromptTemplate
 from langchain_core.vectorstores import VectorStore
+from langchain_core.runnables.base import RunnableSequence
 
 from globals import (
     DEFAULT_QUESTION1,
@@ -21,7 +22,7 @@ from semantic import (
     SemanticRAGChainFactory
 )
 
-_semantic_rag_chain = SemanticRAGChainFactory.get_semantic_rag_chain()
+_semantic_rag_chain: RunnableSequence = None
 
 @cl.on_message
 async def main(message: cl.Message):
@@ -50,6 +51,12 @@ async def start():
         name="User",
         url="https://media.architecturaldigest.com/photos/5f241de2c850b2a36b415024/master/w_1600%2Cc_limit/Luke-logo.png"
     ).send()
+
+    global _semantic_rag_chain
+    _semantic_rag_chain = SemanticRAGChainFactory.get_semantic_rag_chain()
+
+    _logger.info("\tsending message back: ready!!!")
+
     content = ""
     # if _semantic_rag_chain is not None:
     #     try:
@@ -66,7 +73,6 @@ async def start():
     #         _logger.error(f"init error: {e}")
     
     cl.user_session.set("message_history", [{"role": "system", "content": "You are a helpful assistant. "}])
-    _logger.info("\tsending message back: ready!!!")
     await cl.Message(
         content=content + "\nHow can I help you with Meta's 2023 10K?"
     ).send()