Update backend.py

backend.py

@@ -217,12 +217,15 @@ def initialize_qa_system(_vector_store):
             api_key=os.environ.get("OPENAI_API_KEY"),
         )
 
-       prompt = ChatPromptTemplate.from_messages([
-            ("system", "You are a helpful assistant"),
-            MessagesPlaceholder(variable_name="chat_history"),   
-
-            ("human", "{input}"),
-            MessagesPlaceholder(variable_name="agent_scratchpad"),  
+        # Define the prompt template (ADD agent_scratchpad)
+        prompt = ChatPromptTemplate.from_messages(
+            [
+                ("system", "You are a helpful assistant"),
+                MessagesPlaceholder(variable_name="chat_history"),
+                ("human", "{input}"),
+                MessagesPlaceholder(variable_name="agent_scratchpad"),
+            ]
+        )
 
         # Define the tools
         tools = [