feat(channel): echo voice audio transcription feedback

config/config.example.json

@@ -477,6 +477,9 @@
     "enabled": false,
     "monitor_usb": true
   },
+  "voice": {
+    "echo_transcription": false
+  },
   "gateway": {
     "host": "127.0.0.1",
     "port": 18790

pkg/agent/loop.go

@@ -467,9 +467,10 @@ var audioAnnotationRe = regexp.MustCompile(`\[(voice|audio)(?::[^\]]*)?\]`)
 
 // transcribeAudioInMessage resolves audio media refs, transcribes them, and
 // replaces audio annotations in msg.Content with the transcribed text.
-func (al *AgentLoop) transcribeAudioInMessage(ctx context.Context, msg bus.InboundMessage) bus.InboundMessage {
+// Returns the (possibly modified) message and true if audio was transcribed.
+func (al *AgentLoop) transcribeAudioInMessage(ctx context.Context, msg bus.InboundMessage) (bus.InboundMessage, bool) {
 	if al.transcriber == nil || al.mediaStore == nil || len(msg.Media) == 0 {
-		return msg
+		return msg, false
 	}
 
 	// Transcribe each audio media ref in order.
@@ -493,9 +494,11 @@ func (al *AgentLoop) transcribeAudioInMessage(ctx context.Context, msg bus.Inbou
 	}
 
 	if len(transcriptions) == 0 {
-		return msg
+		return msg, false
 	}
 
+	al.sendTranscriptionFeedback(ctx, msg.Channel, msg.ChatID, msg.MessageID, transcriptions)
+
 	// Replace audio annotations sequentially with transcriptions.
 	idx := 0
 	newContent := audioAnnotationRe.ReplaceAllStringFunc(msg.Content, func(match string) string {
@@ -513,7 +516,48 @@ func (al *AgentLoop) transcribeAudioInMessage(ctx context.Context, msg bus.Inbou
 	}
 
 	msg.Content = newContent
-	return msg
+	return msg, true
+}
+
+// sendTranscriptionFeedback sends feedback to the user with the result of
+// audio transcription if the option is enabled. It uses Manager.SendMessage
+// which executes synchronously (rate limiting, splitting, retry) so that
+// ordering with the subsequent placeholder is guaranteed.
+func (al *AgentLoop) sendTranscriptionFeedback(
+	ctx context.Context,
+	channel, chatID, messageID string,
+	validTexts []string,
+) {
+	if !al.cfg.Voice.EchoTranscription {
+		return
+	}
+	if al.channelManager == nil {
+		return
+	}
+
+	var nonEmpty []string
+	for _, t := range validTexts {
+		if t != "" {
+			nonEmpty = append(nonEmpty, t)
+		}
+	}
+
+	var feedbackMsg string
+	if len(nonEmpty) > 0 {
+		feedbackMsg = "Transcript: " + strings.Join(nonEmpty, "\n")
+	} else {
+		feedbackMsg = "No voice detected in the audio"
+	}
+
+	err := al.channelManager.SendMessage(ctx, bus.OutboundMessage{
+		Channel:          channel,
+		ChatID:           chatID,
+		Content:          feedbackMsg,
+		ReplyToMessageID: messageID,
+	})
+	if err != nil {
+		logger.WarnCF("voice", "Failed to send transcription feedback", map[string]any{"error": err.Error()})
+	}
 }
 
 // inferMediaType determines the media type ("image", "audio", "video", "file")
@@ -627,7 +671,14 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 		},
 	)
 
-	msg = al.transcribeAudioInMessage(ctx, msg)
+	var hadAudio bool
+	msg, hadAudio = al.transcribeAudioInMessage(ctx, msg)
+
+	// For audio messages the placeholder was deferred by the channel.
+	// Now that transcription (and optional feedback) is done, send it.
+	if hadAudio && al.channelManager != nil {
+		al.channelManager.SendPlaceholder(ctx, msg.Channel, msg.ChatID)
+	}
 
 	// Route system messages to processSystemMessage
 	if msg.Channel == "system" {

pkg/bus/types.go

@@ -30,9 +30,10 @@ type InboundMessage struct {
 }
 
 type OutboundMessage struct {
-	Channel string `json:"channel"`
-	ChatID  string `json:"chat_id"`
-	Content string `json:"content"`
+	Channel          string `json:"channel"`
+	ChatID           string `json:"chat_id"`
+	Content          string `json:"content"`
+	ReplyToMessageID string `json:"reply_to_message_id,omitempty"`
 }
 
 // MediaPart describes a single media attachment to send.

pkg/channels/base.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"encoding/binary"
 	"encoding/hex"
+	"regexp"
 	"strconv"
 	"strings"
 	"sync/atomic"
@@ -32,6 +33,9 @@ func init() {
 	uniqueIDPrefix = hex.EncodeToString(b[:])
 }
 
+// audioAnnotationRe matches audio/voice annotations injected by channels (e.g. [voice], [audio: file.ogg]).
+var audioAnnotationRe = regexp.MustCompile(`\[(voice|audio)(?::[^\]]*)?\]`)
+
 // uniqueID generates a process-unique ID using a random prefix and an atomic counter.
 // This ID is intended for internal correlation (e.g. media scope keys) and is NOT
 // cryptographically secure — it must not be used in contexts where unpredictability matters.
@@ -284,10 +288,15 @@ func (c *BaseChannel) HandleMessage(
 				c.placeholderRecorder.RecordReactionUndo(c.name, chatID, undo)
 			}
 		}
-		// Placeholder — independent pipeline
-		if pc, ok := c.owner.(PlaceholderCapable); ok {
-			if phID, err := pc.SendPlaceholder(ctx, chatID); err == nil && phID != "" {
-				c.placeholderRecorder.RecordPlaceholder(c.name, chatID, phID)
+		// Placeholder — independent pipeline.
+		// Skip when the message contains audio: the agent will send the
+		// placeholder after transcription completes, so the user sees
+		// "Thinking…" only once the voice has been processed.
+		if !audioAnnotationRe.MatchString(content) {
+			if pc, ok := c.owner.(PlaceholderCapable); ok {
+				if phID, err := pc.SendPlaceholder(ctx, chatID); err == nil && phID != "" {
+					c.placeholderRecorder.RecordPlaceholder(c.name, chatID, phID)
+				}
 			}
 		}
 	}

pkg/channels/discord/discord.go

@@ -134,7 +134,7 @@ func (c *DiscordChannel) Send(ctx context.Context, msg bus.OutboundMessage) erro
 		return nil
 	}
 
-	return c.sendChunk(ctx, channelID, msg.Content)
+	return c.sendChunk(ctx, channelID, msg.Content, msg.ReplyToMessageID)
 }
 
 // SendMedia implements the channels.MediaSender interface.
@@ -259,14 +259,29 @@ func (c *DiscordChannel) SendPlaceholder(ctx context.Context, chatID string) (st
 	return msg.ID, nil
 }
 
-func (c *DiscordChannel) sendChunk(ctx context.Context, channelID, content string) error {
+func (c *DiscordChannel) sendChunk(ctx context.Context, channelID, content, replyToID string) error {
 	// Use the passed ctx for timeout control
 	sendCtx, cancel := context.WithTimeout(ctx, sendTimeout)
 	defer cancel()
 
 	done := make(chan error, 1)
 	go func() {
-		_, err := c.session.ChannelMessageSend(channelID, content)
+		var err error
+
+		// If we have an ID, we send the message as "Reply"
+		if replyToID != "" {
+			_, err = c.session.ChannelMessageSendComplex(channelID, &discordgo.MessageSend{
+				Content: content,
+				Reference: &discordgo.MessageReference{
+					MessageID: replyToID,
+					ChannelID: channelID,
+				},
+			})
+		} else {
+			// Otherwise, we send a normal message
+			_, err = c.session.ChannelMessageSend(channelID, content)
+		}
+
 		done <- err
 	}()
 

pkg/channels/manager.go

@@ -102,6 +102,27 @@ func (m *Manager) RecordPlaceholder(channel, chatID, placeholderID string) {
 	m.placeholders.Store(key, placeholderEntry{id: placeholderID, createdAt: time.Now()})
 }
 
+// SendPlaceholder sends a "Thinking…" placeholder for the given channel/chatID
+// and records it for later editing. Returns true if a placeholder was sent.
+func (m *Manager) SendPlaceholder(ctx context.Context, channel, chatID string) bool {
+	m.mu.RLock()
+	ch, ok := m.channels[channel]
+	m.mu.RUnlock()
+	if !ok {
+		return false
+	}
+	pc, ok := ch.(PlaceholderCapable)
+	if !ok {
+		return false
+	}
+	phID, err := pc.SendPlaceholder(ctx, chatID)
+	if err != nil || phID == "" {
+		return false
+	}
+	m.RecordPlaceholder(channel, chatID, phID)
+	return true
+}
+
 // RecordTypingStop registers a typing stop function for later invocation.
 // Implements PlaceholderRecorder.
 func (m *Manager) RecordTypingStop(channel, chatID string, stop func()) {
@@ -813,6 +834,39 @@ func (m *Manager) UnregisterChannel(name string) {
 	delete(m.channels, name)
 }
 
+// SendMessage sends an outbound message synchronously through the channel
+// worker's rate limiter and retry logic. It blocks until the message is
+// delivered (or all retries are exhausted), which preserves ordering when
+// a subsequent operation depends on the message having been sent.
+func (m *Manager) SendMessage(ctx context.Context, msg bus.OutboundMessage) error {
+	m.mu.RLock()
+	_, exists := m.channels[msg.Channel]
+	w, wExists := m.workers[msg.Channel]
+	m.mu.RUnlock()
+
+	if !exists {
+		return fmt.Errorf("channel %s not found", msg.Channel)
+	}
+	if !wExists || w == nil {
+		return fmt.Errorf("channel %s has no active worker", msg.Channel)
+	}
+
+	maxLen := 0
+	if mlp, ok := w.ch.(MessageLengthProvider); ok {
+		maxLen = mlp.MaxMessageLength()
+	}
+	if maxLen > 0 && len([]rune(msg.Content)) > maxLen {
+		for _, chunk := range SplitMessage(msg.Content, maxLen) {
+			chunkMsg := msg
+			chunkMsg.Content = chunk
+			m.sendWithRetry(ctx, msg.Channel, w, chunkMsg)
+		}
+	} else {
+		m.sendWithRetry(ctx, msg.Channel, w, msg)
+	}
+	return nil
+}
+
 func (m *Manager) SendToChannel(ctx context.Context, channelName, chatID, content string) error {
 	m.mu.RLock()
 	_, exists := m.channels[channelName]