Update error handling

agent.py

@@ -187,19 +187,49 @@ def build_agent_graph(provider: str = "groq"):
     # Assistant: reasoning step that plans next action
     def assistant_node(state: MessagesState) -> dict:
         try:
+            # Validate input state
+            if not isinstance(state, dict) or "messages" not in state:
+                raise ValueError("Invalid state format")
+
             messages = state["messages"]
+            if not messages:
+                raise ValueError("Empty message list")
+
+            # Invoke LLM
             response = llm_with_tools.invoke(messages)
+            if response is None:
+                raise ValueError("LLM returned None response")
 
             # Validate response format
-            if not response or not isinstance(
-                response, (AIMessage, HumanMessage, SystemMessage)
-            ):
-                raise ValueError("Invalid response format from LLM")
+            if not isinstance(response, (AIMessage, HumanMessage, SystemMessage)):
+                raise ValueError(f"Invalid response type from LLM: {type(response)}")
+
+            # Validate response content
+            if not hasattr(response, "content") or response.content is None:
+                raise ValueError("Response missing content")
+
+            if not isinstance(response.content, str):
+                raise ValueError(f"Invalid content type: {type(response.content)}")
+
+            # Ensure response has content
+            if not response.content.strip():
+                raise ValueError("Empty response content")
+
+            # Add FINAL ANSWER prefix if missing
+            content = response.content
+            if "FINAL ANSWER:" not in content:
+                content = f"FINAL ANSWER: {content}"
+            response = AIMessage(content=content)
 
             return {"messages": response}
         except Exception as e:
             error_msg = f"Error in assistant node: {str(e)}"
-            return {"messages": AIMessage(content=f"FINAL ANSWER: {error_msg}")}
+            print(f"Assistant node error: {error_msg}")  # Log error for debugging
+            return {
+                "messages": AIMessage(
+                    content="FINAL ANSWER: Error occurred while processing request. Please try again."
+                )
+            }
 
     # Stubbed retriever node for future integration
     def retriever_node(state: MessagesState):

app.py

@@ -25,53 +25,54 @@ class BasicAgent:
     def __call__(self, question: str) -> str:
         print(f"Agent received question (first 50 chars): {question[:50]}...")
         try:
+            # Import system prompt from agent module
+            from agent import system_prompt
+
             # Create properly typed messages
-            system_msg = SystemMessage(
-                content="""You are a helpful AI assistant. Format your final answer as:
-FINAL ANSWER: [your answer here]"""
-            )
             human_msg = HumanMessage(content=question)
-            msgs: List[AnyMessage] = [system_msg, human_msg]
+            msgs: List[AnyMessage] = [system_prompt, human_msg]
 
             # Create and cast the state
             input_state = cast(MessagesState, {"messages": msgs})
 
-            # Invoke the graph
-            result = self.graph.invoke(input_state)
+            # Invoke the graph with proper error handling
+            try:
+                result = self.graph.invoke(input_state)
+            except Exception as e:
+                print(f"Graph invocation error: {str(e)}")
+                return f"Error: Failed to process request - {str(e)}"
 
-            # Validate response
-            if not isinstance(result, dict) or "messages" not in result:
-                raise ValueError("Invalid response structure from agent graph")
+            # Validate response structure
+            if not isinstance(result, dict):
+                return "Error: Invalid response format from agent"
 
-            if not result["messages"]:
-                raise ValueError("Empty message list in response")
+            if "messages" not in result or not result["messages"]:
+                return "Error: No response messages from agent"
 
-            # Get the last message content
+            # Get the last message
             last_msg = result["messages"][-1]
             if not isinstance(last_msg, (AIMessage, HumanMessage, SystemMessage)):
-                raise ValueError(f"Invalid message type: {type(last_msg)}")
+                return f"Error: Invalid message type - {type(last_msg)}"
 
+            # Get and validate content
             answer = last_msg.content
             if not isinstance(answer, str):
-                raise ValueError(f"Invalid answer type: {type(answer)}")
+                return f"Error: Invalid answer type - {type(answer)}"
 
-            # Ensure proper formatting
             if not answer.strip():
                 return "Error: Empty response from agent"
 
-            if "FINAL ANSWER:" not in answer:
-                # If no prefix, return as is
-                return answer
-
-            # Extract the actual answer after "FINAL ANSWER:"
-            final_answer = answer.split("FINAL ANSWER:", 1)[1].strip()
-            if not final_answer:
-                return "Error: Empty answer after FINAL ANSWER prefix"
+            # Handle FINAL ANSWER prefix
+            if "FINAL ANSWER:" in answer:
+                parts = answer.split("FINAL ANSWER:", 1)
+                if len(parts) == 2 and parts[1].strip():
+                    return parts[1].strip()
 
-            return final_answer
+            # If no prefix or empty after prefix, return full answer
+            return answer.strip()
 
         except Exception as e:
-            error_msg = f"Error in agent call: {str(e)}"
+            error_msg = f"Error processing request: {str(e)}"
             print(error_msg)
             return error_msg