Update app.py

app.py

@@ -69,6 +69,8 @@ async def initialize_agent(api_key: str = Form(...), model_name: str = Form(...)
             google_api_key=api_key,
             temperature=0.1
         )
+        llm.invoke("Say cheese") # test to see if api key is valid
+        
         system_prompt = (
                     "You are a professional research assistant. Your primary goal is to provide "
                     "accurate, evidence-based information. \n\n"