refactor(channels): Send returns ([]string, error), remove MessageIDsSender

Replace the optional MessageIDsSender interface with a direct return value
on Send. Channels that support delivery IDs (Telegram, Discord, Slack, QQ)
return them from Send; all others return nil. Manager.sendWithRetry drops
the type-assertion branch and calls Send uniformly.

pkg/agent/loop_test.go

@@ -28,7 +28,9 @@ type fakeChannel struct{ id string }
 func (f *fakeChannel) Name() string                                            { return "fake" }
 func (f *fakeChannel) Start(ctx context.Context) error                         { return nil }
 func (f *fakeChannel) Stop(ctx context.Context) error                          { return nil }
-func (f *fakeChannel) Send(ctx context.Context, msg bus.OutboundMessage) error { return nil }
+func (f *fakeChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
+	return nil, nil
+}
 func (f *fakeChannel) IsRunning() bool                                         { return true }
 func (f *fakeChannel) IsAllowed(string) bool                                   { return true }
 func (f *fakeChannel) IsAllowedSender(sender bus.SenderInfo) bool              { return true }

pkg/channels/README.md

@@ -253,27 +253,27 @@ func (c *TelegramChannel) Stop(ctx context.Context) error {
 
 ```go
 // Old code: returns plain error
-func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-    if !c.running { return fmt.Errorf("not running") }
+    if !c.running { return nil, fmt.Errorf("not running") }
     // ...
-    if err != nil { return err }
+    if err != nil { return nil, err }
 }
 
 // New code: must return sentinel errors for Manager to determine retry strategy
-func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
     if !c.IsRunning() {
-        return channels.ErrNotRunning    // ← Manager will not retry
+        return nil, channels.ErrNotRunning    // ← Manager will not retry
     }
     // ...
     if err != nil {
         // Use ClassifySendError to wrap error based on HTTP status code
-        return channels.ClassifySendError(statusCode, err)
+        return nil, channels.ClassifySendError(statusCode, err)
         // Or manually wrap:
-        // return fmt.Errorf("%w: %v", channels.ErrTemporary, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrTemporary, err)
-        // return fmt.Errorf("%w: %v", channels.ErrRateLimit, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrRateLimit, err)
-        // return fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
     }
-    return nil
+    return nil, nil
 }
 ```
 
@@ -301,6 +301,8 @@ sender := bus.SenderInfo{
     CanonicalID: identity.BuildCanonicalID("telegram", strconv.FormatInt(from.ID, 10)),
     Username:    from.Username,
     DisplayName: from.FirstName,
+    FirstName:   from.FirstName,
+    LastName:    from.LastName,
 }
 
 peer := bus.Peer{
@@ -502,10 +504,10 @@ func (c *MatrixChannel) Stop(ctx context.Context) error {
     return nil
 }
 
-func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
     // 1. Check running state
     if !c.IsRunning() {
-        return channels.ErrNotRunning
+        return nil, channels.ErrNotRunning
     }
 
     // 2. Send message to Matrix
@@ -513,14 +515,14 @@ func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
     if err != nil {
         // 3. Must use error classification wrapping
         //    If you have an HTTP status code:
-        //    return channels.ClassifySendError(statusCode, err)
+        //    return nil, channels.ClassifySendError(statusCode, err)
         //    If it's a network error:
-        //    return channels.ClassifyNetError(err)
+        //    return nil, channels.ClassifyNetError(err)
         //    If manual classification is needed:
-        return fmt.Errorf("%w: %v", channels.ErrTemporary, err)
+        return nil, fmt.Errorf("%w: %v", channels.ErrTemporary, err)
     }
 
-    return nil
+    return nil, nil
 }
 
 // ========== Incoming Message Handling ==========
@@ -868,7 +870,9 @@ type SenderInfo struct {
     PlatformID  string `json:"platform_id,omitempty"`  // Platform-native ID
     CanonicalID string `json:"canonical_id,omitempty"` // "platform:id" canonical format
     Username    string `json:"username,omitempty"`
-    DisplayName string `json:"display_name,omitempty"`
+    DisplayName string `json:"display_name,omitempty"` // fallback display name when first/last not available
+    FirstName   string `json:"first_name,omitempty"`   // given name (preferred over DisplayName when set)
+    LastName    string `json:"last_name,omitempty"`    // family name
 }
 
 // Inbound message
@@ -889,9 +893,11 @@ type InboundMessage struct {
 
 // Outbound text message
 type OutboundMessage struct {
-    Channel string
+    Channel          string                // Target channel name
-    ChatID  string
+    ChatID           string                // Target chat/room ID
-    Content string
+    Content          string                // Message text
+    ReplyToMessageID string                // Optional: reply to this platform message ID
+    OnDelivered      func(msgIDs []string) // Optional: called with delivered platform message IDs (not serialized)
 }
 
 // Outbound media message
@@ -1272,7 +1278,7 @@ type Channel interface {
     Name() string
     Start(ctx context.Context) error
     Stop(ctx context.Context) error
-    Send(ctx context.Context, msg bus.OutboundMessage) error
+    Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error)
     IsRunning() bool
     IsAllowed(senderID string) bool
     IsAllowedSender(sender bus.SenderInfo) bool

pkg/channels/README.zh.md

@@ -253,27 +253,27 @@ func (c *TelegramChannel) Stop(ctx context.Context) error {
 
 ```go
 // 旧代码：返回普通 error
-func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-    if !c.running { return fmt.Errorf("not running") }
+    if !c.running { return nil, fmt.Errorf("not running") }
     // ...
-    if err != nil { return err }
+    if err != nil { return nil, err }
 }
 
 // 新代码：必须返回哨兵错误，供 Manager 判断重试策略
-func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
     if !c.IsRunning() {
-        return channels.ErrNotRunning    // ← Manager 不会重试
+        return nil, channels.ErrNotRunning    // ← Manager 不会重试
     }
     // ...
     if err != nil {
         // 使用 ClassifySendError 根据 HTTP 状态码包装错误
-        return channels.ClassifySendError(statusCode, err)
+        return nil, channels.ClassifySendError(statusCode, err)
         // 或手动包装：
-        // return fmt.Errorf("%w: %v", channels.ErrTemporary, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrTemporary, err)
-        // return fmt.Errorf("%w: %v", channels.ErrRateLimit, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrRateLimit, err)
-        // return fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
+        // return nil, fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
     }
-    return nil
+    return nil, nil
 }
 ```
 
@@ -301,6 +301,8 @@ sender := bus.SenderInfo{
     CanonicalID: identity.BuildCanonicalID("telegram", strconv.FormatInt(from.ID, 10)),
     Username:    from.Username,
     DisplayName: from.FirstName,
+    FirstName:   from.FirstName,
+    LastName:    from.LastName,
 }
 
 peer := bus.Peer{
@@ -502,10 +504,10 @@ func (c *MatrixChannel) Stop(ctx context.Context) error {
     return nil
 }
 
-func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
     // 1. 检查运行状态
     if !c.IsRunning() {
-        return channels.ErrNotRunning
+        return nil, channels.ErrNotRunning
     }
 
     // 2. 发送消息到 Matrix
@@ -513,14 +515,14 @@ func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
     if err != nil {
         // 3. 必须使用错误分类包装
         //    如果你有 HTTP 状态码：
-        //    return channels.ClassifySendError(statusCode, err)
+        //    return nil, channels.ClassifySendError(statusCode, err)
         //    如果是网络错误：
-        //    return channels.ClassifyNetError(err)
+        //    return nil, channels.ClassifyNetError(err)
         //    如果需要手动分类：
-        return fmt.Errorf("%w: %v", channels.ErrTemporary, err)
+        return nil, fmt.Errorf("%w: %v", channels.ErrTemporary, err)
     }
 
-    return nil
+    return nil, nil
 }
 
 // ========== 消息接收处理 ==========
@@ -867,7 +869,9 @@ type SenderInfo struct {
     PlatformID  string `json:"platform_id,omitempty"`  // 平台原始 ID
     CanonicalID string `json:"canonical_id,omitempty"` // "platform:id" 规范格式
     Username    string `json:"username,omitempty"`
-    DisplayName string `json:"display_name,omitempty"`
+    DisplayName string `json:"display_name,omitempty"` // 无 first/last 时的回退显示名
+    FirstName   string `json:"first_name,omitempty"`   // 名（优先于 DisplayName）
+    LastName    string `json:"last_name,omitempty"`    // 姓
 }
 
 // 入站消息
@@ -888,9 +892,11 @@ type InboundMessage struct {
 
 // 出站文本消息
 type OutboundMessage struct {
-    Channel string
+    Channel          string                // 目标 channel 名称
-    ChatID  string
+    ChatID           string                // 目标聊天/房间 ID
-    Content string
+    Content          string                // 消息文本
+    ReplyToMessageID string                // 可选：回复的平台消息 ID
+    OnDelivered      func(msgIDs []string) // 可选：投递成功后携带平台消息 ID 回调（不序列化）
 }
 
 // 出站媒体消息
@@ -1271,7 +1277,7 @@ type Channel interface {
     Name() string
     Start(ctx context.Context) error
     Stop(ctx context.Context) error
-    Send(ctx context.Context, msg bus.OutboundMessage) error
+    Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error)
     IsRunning() bool
     IsAllowed(senderID string) bool
     IsAllowedSender(sender bus.SenderInfo) bool

pkg/channels/base.go

@@ -48,7 +48,7 @@ type Channel interface {
 	Name() string
 	Start(ctx context.Context) error
 	Stop(ctx context.Context) error
-	Send(ctx context.Context, msg bus.OutboundMessage) error
+	Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error)
 	IsRunning() bool
 	IsAllowed(senderID string) bool
 	IsAllowedSender(sender bus.SenderInfo) bool

pkg/channels/dingtalk/dingtalk.go

@@ -103,20 +103,20 @@ func (c *DingTalkChannel) Stop(ctx context.Context) error {
 }
 
 // Send sends a message to DingTalk via the chatbot reply API
-func (c *DingTalkChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *DingTalkChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	// Get session webhook from storage
 	sessionWebhookRaw, ok := c.sessionWebhooks.Load(msg.ChatID)
 	if !ok {
-		return fmt.Errorf("no session_webhook found for chat %s, cannot send message", msg.ChatID)
+		return nil, fmt.Errorf("no session_webhook found for chat %s, cannot send message", msg.ChatID)
 	}
 
 	sessionWebhook, ok := sessionWebhookRaw.(string)
 	if !ok {
-		return fmt.Errorf("invalid session_webhook type for chat %s", msg.ChatID)
+		return nil, fmt.Errorf("invalid session_webhook type for chat %s", msg.ChatID)
 	}
 
 	logger.DebugCF("dingtalk", "Sending message", map[string]any{
@@ -125,7 +125,7 @@ func (c *DingTalkChannel) Send(ctx context.Context, msg bus.OutboundMessage) err
 	})
 
 	// Use the session webhook to send the reply
-	return c.SendDirectReply(ctx, sessionWebhook, msg.Content)
+	return nil, c.SendDirectReply(ctx, sessionWebhook, msg.Content)
 }
 
 // onChatBotMessageReceived implements the IChatBotMessageHandler function signature

pkg/channels/discord/discord.go

@@ -128,13 +128,7 @@ func (c *DiscordChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *DiscordChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *DiscordChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	_, err := c.SendMessageWithIDs(ctx, msg)
-	return err
-}
-
-// SendMessageWithIDs implements channels.MessageIDsSender.
-func (c *DiscordChannel) SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
 		return nil, channels.ErrNotRunning
 	}

pkg/channels/feishu/feishu_32.go

@@ -36,8 +36,8 @@ func (c *FeishuChannel) Stop(ctx context.Context) error {
 }
 
 // Send is a stub method to satisfy the Channel interface
-func (c *FeishuChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *FeishuChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	return errUnsupported
+	return nil, errUnsupported
 }
 
 // EditMessage is a stub method to satisfy MessageEditor

pkg/channels/feishu/feishu_64.go

@@ -131,26 +131,26 @@ func (c *FeishuChannel) Stop(ctx context.Context) error {
 
 // Send sends a message using Interactive Card format for markdown rendering.
 // Falls back to plain text message if card sending fails (e.g., table limit exceeded).
-func (c *FeishuChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *FeishuChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	if msg.ChatID == "" {
-		return fmt.Errorf("chat ID is empty: %w", channels.ErrSendFailed)
+		return nil, fmt.Errorf("chat ID is empty: %w", channels.ErrSendFailed)
 	}
 
 	// Build interactive card with markdown content
 	cardContent, err := buildMarkdownCard(msg.Content)
 	if err != nil {
 		// If card build fails, fall back to plain text
-		return c.sendText(ctx, msg.ChatID, msg.Content)
+		return nil, c.sendText(ctx, msg.ChatID, msg.Content)
 	}
 
 	// First attempt: try sending as interactive card
 	err = c.sendCard(ctx, msg.ChatID, cardContent)
 	if err == nil {
-		return nil
+		return nil, nil
 	}
 
 	// Check if error is due to card table limit (error code 11310)
@@ -167,14 +167,14 @@ func (c *FeishuChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 		// Second attempt: fall back to plain text message
 		textErr := c.sendText(ctx, msg.ChatID, msg.Content)
 		if textErr == nil {
-			return nil
+			return nil, nil
 		}
 		// If text also fails, return the text error
-		return textErr
+		return nil, textErr
 	}
 
 	// For other errors, return the original card error
-	return err
+	return nil, err
 }
 
 // EditMessage implements channels.MessageEditor.

pkg/channels/interfaces.go

@@ -62,12 +62,6 @@ type PlaceholderRecorder interface {
 	RecordReactionUndo(channel, chatID string, undo func())
 }
 
-// MessageIDsSender is implemented by channels that can return the platform
-// message IDs for a delivered outbound text message.
-type MessageIDsSender interface {
-	SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) (messageIDs []string, err error)
-}
-
 // CommandRegistrarCapable is implemented by channels that can register
 // command menus with their upstream platform (e.g. Telegram BotCommand).
 // Channels that do not support platform-level command menus can ignore it.

pkg/channels/irc/irc.go

@@ -130,18 +130,18 @@ func (c *IRCChannel) Stop(ctx context.Context) error {
 }
 
 // Send sends a message to an IRC channel or user.
-func (c *IRCChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *IRCChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	target := msg.ChatID
 	if target == "" {
-		return fmt.Errorf("chat ID is empty: %w", channels.ErrSendFailed)
+		return nil, fmt.Errorf("chat ID is empty: %w", channels.ErrSendFailed)
 	}
 
 	if strings.TrimSpace(msg.Content) == "" {
-		return nil
+		return nil, nil
 	}
 
 	// Send each line separately (IRC is line-oriented)
@@ -158,7 +158,7 @@ func (c *IRCChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
 		"target": target,
 		"lines":  len(lines),
 	})
-	return nil
+	return nil, nil
 }
 
 // StartTyping implements channels.TypingCapable using IRCv3 +typing client tag.

pkg/channels/line/line.go

@@ -496,9 +496,9 @@ func (c *LINEChannel) resolveChatID(source lineSource) string {
 
 // Send sends a message to LINE. It first tries the Reply API (free)
 // using a cached reply token, then falls back to the Push API.
-func (c *LINEChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *LINEChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	// Load and consume quote token for this chat
@@ -516,14 +516,14 @@ func (c *LINEChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
 					"chat_id": msg.ChatID,
 					"quoted":  quoteToken != "",
 				})
-				return nil
+				return nil, nil
 			}
 			logger.DebugC("line", "Reply API failed, falling back to Push API")
 		}
 	}
 
 	// Fall back to Push API
-	return c.sendPush(ctx, msg.ChatID, msg.Content, quoteToken)
+	return nil, c.sendPush(ctx, msg.ChatID, msg.Content, quoteToken)
 }
 
 // SendMedia implements the channels.MediaSender interface.

pkg/channels/maixcam/maixcam.go

@@ -240,15 +240,15 @@ func (c *MaixCamChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *MaixCamChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *MaixCamChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	// Check ctx before entering write path
 	select {
 	case <-ctx.Done():
-		return ctx.Err()
+		return nil, ctx.Err()
 	default:
 	}
 
@@ -257,7 +257,7 @@ func (c *MaixCamChannel) Send(ctx context.Context, msg bus.OutboundMessage) erro
 
 	if len(c.clients) == 0 {
 		logger.WarnC("maixcam", "No MaixCam devices connected")
-		return fmt.Errorf("no connected MaixCam devices")
+		return nil, fmt.Errorf("no connected MaixCam devices")
 	}
 
 	response := map[string]any{
@@ -269,7 +269,7 @@ func (c *MaixCamChannel) Send(ctx context.Context, msg bus.OutboundMessage) erro
 
 	data, err := json.Marshal(response)
 	if err != nil {
-		return fmt.Errorf("failed to marshal response: %w", err)
+		return nil, fmt.Errorf("failed to marshal response: %w", err)
 	}
 
 	var sendErr error
@@ -285,5 +285,5 @@ func (c *MaixCamChannel) Send(ctx context.Context, msg bus.OutboundMessage) erro
 		_ = conn.SetWriteDeadline(time.Time{})
 	}
 
-	return sendErr
+	return nil, sendErr
 }

pkg/channels/manager.go

@@ -705,14 +705,8 @@ func (m *Manager) sendWithRetry(
 
 	var lastErr error
 	var msgIDs []string
-	sender, hasMessageIDsSender := w.ch.(MessageIDsSender)
 	for attempt := 0; attempt <= maxRetries; attempt++ {
-		msgIDs = nil
+		msgIDs, lastErr = w.ch.Send(ctx, msg)
-		if hasMessageIDsSender {
-			msgIDs, lastErr = sender.SendMessageWithIDs(ctx, msg)
-		} else {
-			lastErr = w.ch.Send(ctx, msg)
-		}
 		if lastErr == nil {
 			return msgIDs, true
 		}
@@ -1161,5 +1155,6 @@ func (m *Manager) SendToChannel(ctx context.Context, channelName, chatID, conten
 
 	// Fallback: direct send (should not happen)
 	channel, _ := m.channels[channelName]
-	return channel.Send(ctx, msg)
+	_, err := channel.Send(ctx, msg)
+	return err
 }

pkg/channels/manager_test.go

@@ -26,20 +26,15 @@ type mockChannel struct {
 	lastPlaceholderID string
 }
 
-func (m *mockChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (m *mockChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	m.sentMessages = append(m.sentMessages, msg)
-	return m.sendFn(ctx, msg)
+	if m.sendWithIDsFn != nil {
-}
+		return m.sendWithIDsFn(ctx, msg)
-
-func (m *mockChannel) SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	m.sentMessages = append(m.sentMessages, msg)
-	if m.sendWithIDsFn == nil {
-		if m.sendFn == nil {
-			return nil, nil
-		}
-		return nil, m.sendFn(ctx, msg)
 	}
-	return m.sendWithIDsFn(ctx, msg)
+	if m.sendFn == nil {
+		return nil, nil
+	}
+	return nil, m.sendFn(ctx, msg)
 }
 
 func (m *mockChannel) Start(ctx context.Context) error { return nil }

pkg/channels/matrix/matrix.go

@@ -379,26 +379,26 @@ func markdownToHTML(md string) string {
 	return strings.TrimSpace(string(markdown.ToHTML([]byte(md), p, renderer)))
 }
 
-func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *MatrixChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	roomID := id.RoomID(strings.TrimSpace(msg.ChatID))
 	if roomID == "" {
-		return fmt.Errorf("matrix room ID is empty: %w", channels.ErrSendFailed)
+		return nil, fmt.Errorf("matrix room ID is empty: %w", channels.ErrSendFailed)
 	}
 
 	content := strings.TrimSpace(msg.Content)
 	if content == "" {
-		return nil
+		return nil, nil
 	}
 
 	_, err := c.client.SendMessageEvent(ctx, roomID, event.EventMessage, c.messageContent(content))
 	if err != nil {
-		return fmt.Errorf("matrix send: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("matrix send: %w", channels.ErrTemporary)
 	}
-	return nil
+	return nil, nil
 }
 
 func (c *MatrixChannel) messageContent(text string) *event.MessageEventContent {

pkg/channels/onebot/onebot.go

@@ -391,15 +391,15 @@ func (c *OneBotChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *OneBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *OneBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	// Check ctx before entering write path
 	select {
 	case <-ctx.Done():
-		return ctx.Err()
+		return nil, ctx.Err()
 	default:
 	}
 
@@ -408,12 +408,12 @@ func (c *OneBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 	c.mu.Unlock()
 
 	if conn == nil {
-		return fmt.Errorf("OneBot WebSocket not connected")
+		return nil, fmt.Errorf("OneBot WebSocket not connected")
 	}
 
 	action, params, err := c.buildSendRequest(msg)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	echo := fmt.Sprintf("send_%d", atomic.AddInt64(&c.echoCounter, 1))
@@ -426,7 +426,7 @@ func (c *OneBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 
 	data, err := json.Marshal(req)
 	if err != nil {
-		return fmt.Errorf("failed to marshal OneBot request: %w", err)
+		return nil, fmt.Errorf("failed to marshal OneBot request: %w", err)
 	}
 
 	c.writeMu.Lock()
@@ -439,10 +439,10 @@ func (c *OneBotChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 		logger.ErrorCF("onebot", "Failed to send message", map[string]any{
 			"error": err.Error(),
 		})
-		return fmt.Errorf("onebot send: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("onebot send: %w", channels.ErrTemporary)
 	}
 
-	return nil
+	return nil, nil
 }
 
 // SendMedia implements the channels.MediaSender interface.

pkg/channels/pico/client.go

@@ -273,22 +273,22 @@ func (c *PicoClientChannel) handleServerMessage(pc *picoConn, msg PicoMessage) {
 }
 
 // Send sends a message to the remote server.
-func (c *PicoClientChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *PicoClientChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 	c.mu.Lock()
 	pc := c.conn
 	c.mu.Unlock()
 	if pc == nil || pc.closed.Load() {
-		return channels.ErrSendFailed
+		return nil, channels.ErrSendFailed
 	}
 
 	outMsg := newMessage(TypeMessageSend, map[string]any{
 		"content": msg.Content,
 	})
 	outMsg.SessionID = strings.TrimPrefix(msg.ChatID, "pico_client:")
-	return pc.writeJSON(outMsg)
+	return nil, pc.writeJSON(outMsg)
 }
 
 // StartTyping implements channels.TypingCapable.

pkg/channels/pico/client_test.go

@@ -46,7 +46,7 @@ func TestSend_NotRunning(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ch.Send(context.Background(), bus.OutboundMessage{Content: "hi"})
+	_, err = ch.Send(context.Background(), bus.OutboundMessage{Content: "hi"})
 	if !errors.Is(err, channels.ErrNotRunning) {
 		t.Fatalf("expected ErrNotRunning, got %v", err)
 	}
@@ -124,7 +124,7 @@ func TestClientChannel_ConnectAndSend(t *testing.T) {
 	defer ch.Stop(ctx)
 
 	// Send a message
-	err = ch.Send(ctx, bus.OutboundMessage{
+	_, err = ch.Send(ctx, bus.OutboundMessage{
 		ChatID:  "pico_client:sess-1",
 		Content: "hello",
 	})
@@ -179,7 +179,7 @@ func TestClientChannel_ReceivesServerMessage(t *testing.T) {
 	defer ch.Stop(ctx)
 
 	// Send a message; the echo server replies with message.create
-	err = ch.Send(ctx, bus.OutboundMessage{
+	_, err = ch.Send(ctx, bus.OutboundMessage{
 		ChatID:  "pico_client:sess-echo",
 		Content: "ping",
 	})
@@ -252,7 +252,7 @@ func TestSend_ClosedConnection(t *testing.T) {
 	ch.conn.close()
 	ch.mu.Unlock()
 
-	err = ch.Send(ctx, bus.OutboundMessage{
+	_, err = ch.Send(ctx, bus.OutboundMessage{
 		ChatID:  "pico_client:sess-close",
 		Content: "should fail",
 	})

pkg/channels/pico/pico.go

@@ -234,16 +234,16 @@ func (c *PicoChannel) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 // Send implements Channel — sends a message to the appropriate WebSocket connection.
-func (c *PicoChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *PicoChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	outMsg := newMessage(TypeMessageCreate, map[string]any{
 		"content": msg.Content,
 	})
 
-	return c.broadcastToSession(msg.ChatID, outMsg)
+	return nil, c.broadcastToSession(msg.ChatID, outMsg)
 }
 
 // EditMessage implements channels.MessageEditor.

pkg/channels/qq/qq.go

@@ -200,13 +200,7 @@ func (c *QQChannel) getChatKind(chatID string) string {
 	return "group"
 }
 
-func (c *QQChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *QQChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	_, err := c.SendMessageWithIDs(ctx, msg)
-	return err
-}
-
-// SendMessageWithIDs implements channels.MessageIDsSender.
-func (c *QQChannel) SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
 		return nil, channels.ErrNotRunning
 	}

pkg/channels/slack/slack.go

@@ -108,13 +108,7 @@ func (c *SlackChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *SlackChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *SlackChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	_, err := c.SendMessageWithIDs(ctx, msg)
-	return err
-}
-
-// SendMessageWithIDs implements channels.MessageIDsSender.
-func (c *SlackChannel) SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
 		return nil, channels.ErrNotRunning
 	}

pkg/channels/telegram/telegram.go

@@ -168,13 +168,7 @@ func (c *TelegramChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *TelegramChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
-	_, err := c.SendMessageWithIDs(ctx, msg)
-	return err
-}
-
-// SendMessageWithIDs implements channels.MessageIDsSender.
-func (c *TelegramChannel) SendMessageWithIDs(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
 		return nil, channels.ErrNotRunning
 	}

pkg/channels/telegram/telegram_test.go

@@ -236,7 +236,7 @@ func TestSend_EmptyContent(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: "",
 	})
@@ -253,7 +253,7 @@ func TestSend_ShortMessage_SingleCall(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: "Hello, world!",
 	})
@@ -276,7 +276,7 @@ func TestSend_LongMessage_SingleCall(t *testing.T) {
 
 	longContent := strings.Repeat("a", 4000)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: longContent,
 	})
@@ -295,7 +295,7 @@ func TestSendMessageWithIDs_ReturnsAllChunkIDsAfterHTMLResplit(t *testing.T) {
 	chunk := "[x](https://example.com/" + strings.Repeat("a", 20) + ") "
 	content := strings.Repeat(chunk, 120)
 
-	ids, err := ch.SendMessageWithIDs(context.Background(), bus.OutboundMessage{
+	ids, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: content,
 	})
@@ -320,7 +320,7 @@ func TestSend_HTMLFallback_PerChunk(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: "Hello **world**",
 	})
@@ -338,7 +338,7 @@ func TestSend_HTMLFallback_BothFail(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: "Hello",
 	})
@@ -360,7 +360,7 @@ func TestSend_LongMessage_HTMLFallback_StopsOnError(t *testing.T) {
 
 	longContent := strings.Repeat("x", 4001)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: longContent,
 	})
@@ -390,7 +390,7 @@ func TestSend_MarkdownShortButHTMLLong_MultipleCalls(t *testing.T) {
 		"HTML expansion must exceed Telegram limit for this test to be meaningful",
 	)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: markdownContent,
 	})
@@ -425,7 +425,7 @@ func TestSend_HTMLOverflow_WordBoundary(t *testing.T) {
 	// Ensure the test content matches the intended boundary conditions.
 	assert.LessOrEqual(t, len([]rune(content)), 4000, "markdown content must not exceed chunk size for this test")
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "123456",
 		Content: content,
 	})
@@ -461,7 +461,7 @@ func TestSend_NotRunning(t *testing.T) {
 	ch := newTestChannel(t, caller)
 	ch.SetRunning(false)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "12345",
 		Content: "Hello",
 	})
@@ -479,7 +479,7 @@ func TestSend_InvalidChatID(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "not-a-number",
 		Content: "Hello",
 	})
@@ -536,7 +536,7 @@ func TestSend_WithForumThreadID(t *testing.T) {
 	}
 	ch := newTestChannel(t, caller)
 
-	err := ch.Send(context.Background(), bus.OutboundMessage{
+	_, err := ch.Send(context.Background(), bus.OutboundMessage{
 		ChatID:  "-1001234567890/42",
 		Content: "Hello from topic",
 	})

pkg/channels/wecom/wecom.go

@@ -184,20 +184,20 @@ func (c *WeComChannel) BeginStream(_ context.Context, chatID string) (channels.S
 	}, nil
 }
 
-func (c *WeComChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *WeComChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 	content := strings.TrimSpace(msg.Content)
 	if content == "" {
-		return nil
+		return nil, nil
 	}
 
 	if turn, ok := c.getTurn(msg.ChatID); ok {
 		if time.Since(turn.CreatedAt) <= wecomStreamMaxDuration {
 			if err := c.sendStreamReply(turn, content); err == nil {
 				c.consumeTurn(msg.ChatID, turn)
-				return nil
+				return nil, nil
 			}
 		}
 		c.consumeTurn(msg.ChatID, turn)
@@ -205,15 +205,15 @@ func (c *WeComChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 
 	if route, ok := c.routes.Get(msg.ChatID); ok {
 		if err := c.sendActivePush(route.ChatID, route.ChatType, content); err != nil {
-			return err
+			return nil, err
 		}
-		return nil
+		return nil, nil
 	}
 
 	if err := c.sendActivePush(msg.ChatID, 0, content); err != nil {
-		return err
+		return nil, err
 	}
-	return nil
+	return nil, nil
 }
 
 func (c *WeComChannel) SendMedia(ctx context.Context, msg bus.OutboundMediaMessage) error {

pkg/channels/weixin/weixin.go

@@ -313,16 +313,16 @@ func (c *WeixinChannel) handleInboundMessage(ctx context.Context, msg WeixinMess
 }
 
 // Send implements channels.Channel by sending a text message to the WeChat user.
-func (c *WeixinChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *WeixinChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 	if err := c.ensureSessionActive(); err != nil {
-		return err
+		return nil, err
 	}
 
 	if msg.Content == "" {
-		return nil
+		return nil, nil
 	}
 
 	// We need a context_token to send a reply. It should be stored in the conversation metadata.
@@ -341,7 +341,7 @@ func (c *WeixinChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 		logger.ErrorCF("weixin", "Missing context token, cannot send message", map[string]any{
 			"to_user_id": toUserID,
 		})
-		return fmt.Errorf("weixin send: %w: missing context token for chat %s", channels.ErrSendFailed, toUserID)
+		return nil, fmt.Errorf("weixin send: %w: missing context token for chat %s", channels.ErrSendFailed, toUserID)
 	}
 
 	if err := c.sendTextMessage(ctx, toUserID, contextToken, msg.Content); err != nil {
@@ -350,10 +350,10 @@ func (c *WeixinChannel) Send(ctx context.Context, msg bus.OutboundMessage) error
 			"error":      err.Error(),
 		})
 		if c.remainingPause() > 0 {
-			return fmt.Errorf("weixin send: %w", channels.ErrSendFailed)
+			return nil, fmt.Errorf("weixin send: %w", channels.ErrSendFailed)
 		}
-		return fmt.Errorf("weixin send: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("weixin send: %w", channels.ErrTemporary)
 	}
 
-	return nil
+	return nil, nil
 }

pkg/channels/whatsapp/whatsapp.go

@@ -104,15 +104,15 @@ func (c *WhatsAppChannel) Stop(ctx context.Context) error {
 	return nil
 }
 
-func (c *WhatsAppChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *WhatsAppChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 
 	// Check ctx before acquiring lock
 	select {
 	case <-ctx.Done():
-		return ctx.Err()
+		return nil, ctx.Err()
 	default:
 	}
 
@@ -120,7 +120,7 @@ func (c *WhatsAppChannel) Send(ctx context.Context, msg bus.OutboundMessage) err
 	defer c.mu.Unlock()
 
 	if c.conn == nil {
-		return fmt.Errorf("whatsapp connection not established: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("whatsapp connection not established: %w", channels.ErrTemporary)
 	}
 
 	payload := map[string]any{
@@ -131,17 +131,17 @@ func (c *WhatsAppChannel) Send(ctx context.Context, msg bus.OutboundMessage) err
 
 	data, err := json.Marshal(payload)
 	if err != nil {
-		return fmt.Errorf("failed to marshal message: %w", err)
+		return nil, fmt.Errorf("failed to marshal message: %w", err)
 	}
 
 	_ = c.conn.SetWriteDeadline(time.Now().Add(10 * time.Second))
 	if err := c.conn.WriteMessage(websocket.TextMessage, data); err != nil {
 		_ = c.conn.SetWriteDeadline(time.Time{})
-		return fmt.Errorf("whatsapp send: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("whatsapp send: %w", channels.ErrTemporary)
 	}
 	_ = c.conn.SetWriteDeadline(time.Time{})
 
-	return nil
+	return nil, nil
 }
 
 func (c *WhatsAppChannel) listen() {

pkg/channels/whatsapp_native/whatsapp_native.go

@@ -396,13 +396,13 @@ func (c *WhatsAppNativeChannel) handleIncoming(evt *events.Message) {
 	c.HandleMessage(c.runCtx, peer, messageID, senderID, chatID, content, mediaPaths, metadata, sender)
 }
 
-func (c *WhatsAppNativeChannel) Send(ctx context.Context, msg bus.OutboundMessage) error {
+func (c *WhatsAppNativeChannel) Send(ctx context.Context, msg bus.OutboundMessage) ([]string, error) {
 	if !c.IsRunning() {
-		return channels.ErrNotRunning
+		return nil, channels.ErrNotRunning
 	}
 	select {
 	case <-ctx.Done():
-		return ctx.Err()
+		return nil, ctx.Err()
 	default:
 	}
 
@@ -411,18 +411,18 @@ func (c *WhatsAppNativeChannel) Send(ctx context.Context, msg bus.OutboundMessag
 	c.mu.Unlock()
 
 	if client == nil || !client.IsConnected() {
-		return fmt.Errorf("whatsapp connection not established: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("whatsapp connection not established: %w", channels.ErrTemporary)
 	}
 
 	// Detect unpaired state: the client is connected (to WhatsApp servers)
 	// but has not completed QR-login yet, so sending would fail.
 	if client.Store.ID == nil {
-		return fmt.Errorf("whatsapp not yet paired (QR login pending): %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("whatsapp not yet paired (QR login pending): %w", channels.ErrTemporary)
 	}
 
 	to, err := parseJID(msg.ChatID)
 	if err != nil {
-		return fmt.Errorf("invalid chat id %q: %w", msg.ChatID, err)
+		return nil, fmt.Errorf("invalid chat id %q: %w", msg.ChatID, err)
 	}
 
 	waMsg := &waE2E.Message{
@@ -430,9 +430,9 @@ func (c *WhatsAppNativeChannel) Send(ctx context.Context, msg bus.OutboundMessag
 	}
 
 	if _, err = client.SendMessage(ctx, to, waMsg); err != nil {
-		return fmt.Errorf("whatsapp send: %w", channels.ErrTemporary)
+		return nil, fmt.Errorf("whatsapp send: %w", channels.ErrTemporary)
 	}
-	return nil
+	return nil, nil
 }
 
 // parseJID converts a chat ID (phone number or JID string) to types.JID.