better error handling for workers down. sure steve, ship code the day before the keynote

api/main.py

@@ -3,7 +3,9 @@ from typing import Optional
 from temporalio.client import Client
 from temporalio.exceptions import TemporalError
 from temporalio.api.enums.v1 import WorkflowExecutionStatus
+from fastapi import HTTPException
 from dotenv import load_dotenv
+import asyncio
 import os
 
 from workflows.agent_goal_workflow import AgentGoalWorkflow
@@ -18,12 +20,13 @@ temporal_client: Optional[Client] = None
 # Load environment variables
 load_dotenv()
 
+
 def get_agent_goal():
     """Get the agent goal from environment variables."""
     goal_name = os.getenv("AGENT_GOAL", "goal_match_train_invoice")
     goals = {
         "goal_match_train_invoice": goal_match_train_invoice,
-        "goal_event_flight_invoice": goal_event_flight_invoice
+        "goal_event_flight_invoice": goal_event_flight_invoice,
     }
     return goals.get(goal_name, goal_event_flight_invoice)
 
@@ -76,32 +79,44 @@ async def get_conversation_history():
     try:
         handle = temporal_client.get_workflow_handle("agent-workflow")
 
-        status_names = {
-            WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_TERMINATED: "WORKFLOW_EXECUTION_STATUS_TERMINATED",
-            WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_CANCELED: "WORKFLOW_EXECUTION_STATUS_CANCELED",
-            WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_FAILED: "WORKFLOW_EXECUTION_STATUS_FAILED",
-        }
-
         failed_states = [
             WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_TERMINATED,
             WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_CANCELED,
             WorkflowExecutionStatus.WORKFLOW_EXECUTION_STATUS_FAILED,
         ]
 
-        # Check workflow status first
         description = await handle.describe()
         if description.status in failed_states:
-            status_name = status_names.get(description.status, "UNKNOWN_STATUS")
+            print("Workflow is in a failed state. Returning empty history.")
-            print(f"Workflow is in {status_name} state. Returning empty history.")
             return []
 
-        # Only query if workflow is running
+        # Set a timeout for the query
-        conversation_history = await handle.query("get_conversation_history")
+        try:
-        return conversation_history
+            conversation_history = await asyncio.wait_for(
+                handle.query("get_conversation_history"),
+                timeout=5,  # Timeout after 5 seconds
+            )
+            return conversation_history
+        except asyncio.TimeoutError:
+            raise HTTPException(
+                status_code=404,
+                detail="Temporal query timed out (worker may be unavailable).",
+            )
 
     except TemporalError as e:
-        print(f"Temporal error: {e}")
+        error_message = str(e)
-        return []
+        print(f"Temporal error: {error_message}")
+
+        # If worker is down or no poller is available, return a 404
+        if "no poller seen for task queue recently" in error_message:
+            raise HTTPException(
+                status_code=404, detail="Workflow worker unavailable or not found."
+            )
+
+        # For other Temporal errors, return a 500
+        raise HTTPException(
+            status_code=500, detail="Internal server error while querying workflow."
+        )
 
 
 @app.post("/send-prompt")
@@ -155,7 +170,7 @@ async def end_chat():
 async def start_workflow():
     # Get the configured goal
     agent_goal = get_agent_goal()
-    
+
     # Create combined input
     combined_input = CombinedInput(
         tool_params=AgentGoalWorkflowParams(None, None),

frontend/src/pages/App.jsx

@@ -38,68 +38,84 @@ export default function App() {
 
     const debouncedUserInput = useDebounce(userInput, DEBOUNCE_DELAY);
 
-    // Error handling utility with auto-dismiss
+    const errorTimerRef = useRef(null);
+
     const handleError = useCallback((error, context) => {
         console.error(`${context}:`, error);
-        const errorMessage = error.status === 400 
-            ? error.message 
-            : `Error ${context.toLowerCase()}. Please try again.`;
-            
-        setError({
-            visible: true,
-            message: errorMessage
-        });
         
-        const timer = setTimeout(() => setError(INITIAL_ERROR_STATE), 3000);
+        const isConversationFetchError = error.status === 404;
-        return () => clearTimeout(timer);
+        const errorMessage = isConversationFetchError 
+            ? "Error fetching conversation. Retrying..."  // Updated message
+            : `Error ${context.toLowerCase()}. Please try again.`;
+    
+        setError(prevError => {
+            // If the same 404 error is already being displayed, don't reset state (prevents flickering)
+            if (prevError.visible && prevError.message === errorMessage) {
+                return prevError;
+            }
+            return { visible: true, message: errorMessage };
+        });
+    
+        // Clear any existing timeout
+        if (errorTimerRef.current) {
+            clearTimeout(errorTimerRef.current);
+        }
+    
+        // Only auto-dismiss non-404 errors after 3 seconds
+        if (!isConversationFetchError) {
+            errorTimerRef.current = setTimeout(() => setError(INITIAL_ERROR_STATE), 3000);
+        }
     }, []);
-
+    
+    
+    const clearErrorOnSuccess = useCallback(() => {
+        if (errorTimerRef.current) {
+            clearTimeout(errorTimerRef.current);
+        }
+        setError(INITIAL_ERROR_STATE);
+    }, []);
+    
     const fetchConversationHistory = useCallback(async () => {
         try {
             const data = await apiService.getConversationHistory();
             const newConversation = data.messages || [];
             
-            setConversation(prevConversation => {
+            setConversation(prevConversation => 
-                // Only update if there are actual changes
+                JSON.stringify(prevConversation) !== JSON.stringify(newConversation) ? newConversation : prevConversation
-                if (JSON.stringify(prevConversation) !== JSON.stringify(newConversation)) {
+            );
-                    return newConversation;
+    
-                }
-                return prevConversation;
-            });
-
             if (newConversation.length > 0) {
                 const lastMsg = newConversation[newConversation.length - 1];
                 const isAgentMessage = lastMsg.actor === "agent";
                 
                 setLoading(!isAgentMessage);
                 setDone(lastMsg.response.next === "done");
-
+    
-                setLastMessage(prevLastMessage => {
+                setLastMessage(prevLastMessage =>
-                    if (!prevLastMessage || lastMsg.response.response !== prevLastMessage.response.response) {
+                    !prevLastMessage || lastMsg.response.response !== prevLastMessage.response.response
-                        return lastMsg;
+                        ? lastMsg
-                    }
+                        : prevLastMessage
-                    return prevLastMessage;
+                );
-                });
             } else {
                 setLoading(false);
                 setDone(true);
                 setLastMessage(null);
             }
+    
+            // Successfully fetched data, clear any persistent errors
+            clearErrorOnSuccess();
         } catch (err) {
             handleError(err, "fetching conversation");
         }
-    }, [handleError]);
+    }, [handleError, clearErrorOnSuccess]);
-
+    
     // Setup polling with cleanup
     useEffect(() => {
         pollingRef.current = setInterval(fetchConversationHistory, POLL_INTERVAL);
         
-        return () => {
+        return () => clearInterval(pollingRef.current);
-            if (pollingRef.current) {
-                clearInterval(pollingRef.current);
-            }
-        };
     }, [fetchConversationHistory]);
+    
 
     const scrollToBottom = useCallback(() => {
         if (containerRef.current) {