diff --git a/examples/chat-ui/src/hooks/useStreamResponse.ts b/examples/chat-ui/src/hooks/useStreamResponse.ts
index e296b56..93a98f1 100644
--- a/examples/chat-ui/src/hooks/useStreamResponse.ts
+++ b/examples/chat-ui/src/hooks/useStreamResponse.ts
@@ -489,11 +489,30 @@ export const useStreamResponse = ({
                         const updated = [...prev]
                         const conv = updated.find((c) => c.id === conversationId)
                         if (conv) {
-                            conv.messages.push({ 
-                                role: 'assistant', 
-                                content: finalContent
-                            })
-                            debugLog(`[useStreamResponse] Added final assistant response:`, finalContent)
+                            // Check if there's already an assistant message with only reasoning content
+                            const existingAssistantMsg = assistantMessageIndex >= 0 ? conv.messages[assistantMessageIndex] : null
+                            if (existingAssistantMsg && 
+                                existingAssistantMsg.role === 'assistant' && 
+                                (!existingAssistantMsg.content || existingAssistantMsg.content.trim() === '') &&
+                                existingAssistantMsg.reasoning) {
+                                // Update the existing assistant message with final content
+                                existingAssistantMsg.content = finalContent
+                                debugLog(`[useStreamResponse] Updated existing assistant message with final content:`, finalContent)
+                            } else {
+                                // Check if we already have a message with this content to avoid duplicates
+                                const isDuplicate = conv.messages.some(msg => 
+                                    msg.role === 'assistant' && msg.content === finalContent
+                                )
+                                if (!isDuplicate) {
+                                    conv.messages.push({ 
+                                        role: 'assistant', 
+                                        content: finalContent
+                                    })
+                                    debugLog(`[useStreamResponse] Added new final assistant response:`, finalContent)
+                                } else {
+                                    debugLog(`[useStreamResponse] Skipping duplicate assistant response:`, finalContent)
+                                }
+                            }
                         }
                         return updated
                     })