diff --git a/pkg/channels/qq/qq.go b/pkg/channels/qq/qq.go
index 2ba43cdf3..4b8124398 100644
--- a/pkg/channels/qq/qq.go
+++ b/pkg/channels/qq/qq.go
@@ -30,9 +30,9 @@ type QQChannel struct {
 	sessionManager botgo.SessionManager
 	processedIDs   map[string]bool
 	mu             sync.RWMutex
-}
 	chatTypeMap     map[string]string  // Track whether a ChatID is group or C2C
 	chatTypeMu      sync.RWMutex       // Protects chatTypeMap
+}
 
 func NewQQChannel(cfg config.QQConfig, messageBus *bus.MessageBus) (*QQChannel, error) {
 	base := channels.NewBaseChannel("qq", cfg, messageBus, cfg.AllowFrom,
diff --git a/pkg/tools/subagent.go b/pkg/tools/subagent.go
index 69f1a49a2..f1cbc83a7 100644
--- a/pkg/tools/subagent.go
+++ b/pkg/tools/subagent.go
@@ -216,19 +216,19 @@ After completing the task, provide a clear summary of what was done.`
 	}
 
 	// Send announce message back to main agent
-	if sm.bus != nil {
-		announceContent := fmt.Sprintf("Task '%s' completed.\n\nResult:\n%s", task.Label, task.Result)
-		pubCtx, pubCancel := context.WithTimeout(context.Background(), 5*time.Second)
-		defer pubCancel()
-		sm.bus.PublishInbound(pubCtx, bus.InboundMessage{
-			Channel:  "system",
-			SenderID: fmt.Sprintf("subagent:%s", task.ID),
-			// Format: "original_channel:original_chat_id" for routing back
-			ChatID:  fmt.Sprintf("%s:%s", task.OriginChannel, task.OriginChatID),
-			Content: announceContent,
+		// Use sync.Once to ensure the announcement is sent only once
+		task.announcedOnce.Do(func() {
+			announceContent := fmt.Sprintf("Task '%s' completed.\n\nResult:\n%s", task.Label, task.Result)
+			pubCtx, pubCancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer pubCancel()
+			sm.bus.PublishInbound(pubCtx, bus.InboundMessage{
+				Channel:  "system",
+				SenderID: fmt.Sprintf("subagent:%s", task.ID),
+				// Format: "original_channel:original_chat_id" for routing back
+				ChatID:  fmt.Sprintf("%s:%s", task.OriginChannel, task.OriginChatID),
+				Content: announceContent,
+			})
 		})
-	}
-}
 
 func (sm *SubagentManager) GetTask(taskID string) (*SubagentTask, bool) {
 	sm.mu.RLock()