diff --git a/backend/Controllers/DashboardController.cs b/backend/Controllers/DashboardController.cs
index 8b3f243..d771973 100644
--- a/backend/Controllers/DashboardController.cs
+++ b/backend/Controllers/DashboardController.cs
@@ -119,7 +119,7 @@ public class DashboardController(OpenClawGatewayClient gateway, ILogger<Dashboar
     {
         try
         {
-            var key = string.IsNullOrWhiteSpace(sessionKey) ? "iris" : sessionKey.Trim();
+            var key = string.IsNullOrWhiteSpace(sessionKey) ? "agent:iris:main" : sessionKey.Trim();
             var messages = await gateway.GetSessionHistoryAsync(key, Math.Clamp(limit, 1, 200), Math.Max(0, offset));
 
             // Filter: only user and assistant messages (exclude tool/system)
diff --git a/frontend/src/composables/useDashboardData.ts b/frontend/src/composables/useDashboardData.ts
index bdf7cbc..4c59052 100644
--- a/frontend/src/composables/useDashboardData.ts
+++ b/frontend/src/composables/useDashboardData.ts
@@ -280,12 +280,19 @@ async function fetchChatMessages(): Promise<void> {
     const res = await apiFetch('/api/dashboard/chat/messages?limit=50')
     if (!res.ok) return
     const data: DashboardChatMessage[] = await res.json()
-    chatMessages.value = data.map((msg, idx) => ({
-      id: `msg-${idx}`,
-      sender: msg.role === 'assistant' ? 'iris' : 'user',
-      text: msg.content,
-      timestamp: new Date(msg.timestamp).getTime(),
-    }))
+    // Merge instead of replace — only add messages not already present
+    const existingTexts = new Set(chatMessages.value.map(m => m.text))
+    const existingTimestamps = new Set(chatMessages.value.map(m => m.timestamp))
+    for (const msg of data) {
+      const msgTime = new Date(msg.timestamp).getTime()
+      if (existingTexts.has(msg.content) && existingTimestamps.has(msgTime)) continue
+      chatMessages.value.push({
+        id: `msg-${msgTime}-${msg.role}`,
+        sender: msg.role === 'assistant' ? 'iris' : 'user',
+        text: msg.content,
+        timestamp: msgTime,
+      })
+    }
   } catch {
     // API unreachable – keep current values
   }