fix stream

frontend/src/components/thread/ThreadComponent.tsx

@@ -98,6 +98,7 @@ export function ThreadComponent({ projectId, threadId, compact = false, configur
   const latestMessageRef = useRef<HTMLDivElement>(null);
   const initialLayoutAppliedRef = useRef(false);
   const scrollContainerRef = useRef<HTMLDivElement>(null);
+  const lastStreamStartedRef = useRef<string | null>(null); // Track last runId we started streaming for
 
   // Sidebar
   const { state: leftSidebarState, setOpen: setLeftSidebarOpen } = useSidebar();
@@ -637,9 +638,16 @@ export function ThreadComponent({ projectId, threadId, compact = false, configur
   ]);
 
   useEffect(() => {
+    // Prevent duplicate streaming calls for the same runId
+    if (agentRunId && lastStreamStartedRef.current === agentRunId) {
+      return;
+    }
+
     // Start streaming if user initiated a run (don't wait for initialLoadCompleted for first-time users)
     if (agentRunId && agentRunId !== currentHookRunId && userInitiatedRun) {
+      console.log(`[ThreadComponent] Starting user-initiated stream for runId: ${agentRunId}`);
       startStreaming(agentRunId);
+      lastStreamStartedRef.current = agentRunId; // Track that we started this runId
       setUserInitiatedRun(false); // Reset flag after starting
       return;
     }
@@ -652,7 +660,9 @@ export function ThreadComponent({ projectId, threadId, compact = false, configur
       !userInitiatedRun &&
       agentStatus === 'running'
     ) {
+      console.log(`[ThreadComponent] Starting auto stream for runId: ${agentRunId}`);
       startStreaming(agentRunId);
+      lastStreamStartedRef.current = agentRunId; // Track that we started this runId
     }
   }, [
     agentRunId,
@@ -673,9 +683,16 @@ export function ThreadComponent({ projectId, threadId, compact = false, configur
     ) {
       setAgentStatus('idle');
       setAgentRunId(null);
+      // Reset the stream tracking ref when stream completes
+      lastStreamStartedRef.current = null;
     }
   }, [streamHookStatus, agentStatus, setAgentStatus, setAgentRunId]);
 
+  // Reset stream tracking ref when threadId changes  
+  useEffect(() => {
+    lastStreamStartedRef.current = null;
+  }, [threadId]);
+
   // SEO title update
   useEffect(() => {
     if (projectName) {

frontend/src/hooks/useAgentStream.ts

@@ -626,51 +626,54 @@ export function useAgentStream(
 
       console.log(`[useAgentStream] Starting stream for run ID: ${runId}`);
 
-      // Clean up any previous stream
-      if (streamCleanupRef.current) {
-        console.log(`[useAgentStream] Cleaning up previous stream`);
-        streamCleanupRef.current();
-        streamCleanupRef.current = null;
-      }
-
-      // Reset state before starting
-      setTextContent([]);
-      setToolCall(null);
-      setError(null);
-      updateStatus('connecting');
-      setAgentRunId(runId);
-      currentRunIdRef.current = runId; // Set the ref immediately
+      // Store previous stream cleanup for potential restoration
+      const previousCleanup = streamCleanupRef.current;
+      const previousRunId = currentRunIdRef.current;
 
       try {
-        // *** Crucial check: Verify agent is running BEFORE connecting ***
+        // *** Crucial check: Verify agent is running BEFORE cleaning up previous stream ***
         console.log(`[useAgentStream] Checking status for run ID: ${runId}`);
         const agentStatus = await getAgentStatus(runId);
         if (!isMountedRef.current) return; // Check mount status after async call
 
-        // Check if this is still the current run ID we're trying to start
-        if (currentRunIdRef.current !== runId) {
-          console.log(
-            `[useAgentStream] Run ID changed during status check, aborting stream for ${runId}`,
-          );
-          return;
-        }
-
         if (agentStatus.status !== 'running') {
           // Expected when opening an old conversation; don't surface as error/toast
           console.info(
-            `[useAgentStream] Skip streaming for inactive run ${runId} (status: ${agentStatus.status}).`,
+            `[useAgentStream] Stream not started for ${runId}: Agent run ${runId} is not running (status: ${agentStatus.status})`,
           );
-          if (currentRunIdRef.current === runId) {
-            const final =
-              agentStatus.status === 'completed' ||
-              agentStatus.status === 'stopped'
-                ? mapAgentStatus(agentStatus.status)
-                : 'agent_not_running';
+          
+          // DON'T clean up the previous stream if this new one can't start
+          // Just finalize with the appropriate status but keep previous stream if it was working
+          const final =
+            agentStatus.status === 'completed' ||
+            agentStatus.status === 'stopped'
+              ? mapAgentStatus(agentStatus.status)
+              : 'agent_not_running';
+          
+          // Only finalize if we don't have a working previous stream
+          if (!previousRunId || previousRunId === runId) {
             finalizeStream(final, runId);
+          } else {
+            console.log(`[useAgentStream] Keeping previous stream ${previousRunId} active since new stream ${runId} can't start`);
           }
           return;
         }
 
+        // New agent is running, now it's safe to clean up previous stream
+        if (previousCleanup && previousRunId !== runId) {
+          console.log(`[useAgentStream] Cleaning up previous stream ${previousRunId} to start new stream ${runId}`);
+          previousCleanup();
+          streamCleanupRef.current = null;
+        }
+
+        // Reset state for the new stream
+        setTextContent([]);
+        setToolCall(null);
+        setError(null);
+        updateStatus('connecting');
+        setAgentRunId(runId);
+        currentRunIdRef.current = runId; // Set the ref immediately
+
         console.log(
           `[useAgentStream] Agent run ${runId} is running, creating stream`,
         );
@@ -743,13 +746,28 @@ export function useAgentStream(
           console.info(
             `[useAgentStream] Stream not started for ${runId}: ${errorMessage}`,
           );
-          finalizeStream('agent_not_running', runId);
+          
+          // Similar logic - don't finalize if we have a working previous stream
+          if (!previousRunId || previousRunId === runId) {
+            finalizeStream('agent_not_running', runId);
+          } else {
+            console.log(`[useAgentStream] Keeping previous stream ${previousRunId} active since new stream ${runId} failed to start`);
+          }
         } else {
           console.error(
             `[useAgentStream] Error initiating stream for ${runId}: ${errorMessage}`,
           );
           setError(errorMessage);
-          finalizeStream('error', runId);
+          
+          // For unexpected errors, still preserve previous stream if possible
+          if (!previousRunId || previousRunId === runId) {
+            finalizeStream('error', runId);
+          } else {
+            console.log(`[useAgentStream] Keeping previous stream ${previousRunId} active despite error starting new stream ${runId}`);
+            // Reset current run ID back to previous to maintain stream continuity
+            currentRunIdRef.current = previousRunId;
+            setAgentRunId(previousRunId);
+          }
         }
       }
     },