feat: add input_mode flag for voice-optimized LLM responses

Voice mode sends input_mode="voice" through the WebSocket, causing the
server to append voice-specific system prompt instructions that produce
short, conversational responses without markdown formatting for TTS.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

android/core/data/src/main/java/io/picoclaw/android/core/data/mapper/MessageMapper.kt

@@ -66,10 +66,11 @@ object MessageMapper {
         )
     }
 
-    fun toWsIncoming(text: String, base64Images: List<String>): WsIncoming {
+    fun toWsIncoming(text: String, base64Images: List<String>, inputMode: String? = null): WsIncoming {
         return WsIncoming(
             content = text,
-            images = base64Images.ifEmpty { null }
+            images = base64Images.ifEmpty { null },
+            inputMode = inputMode
         )
     }
 }

android/core/data/src/main/java/io/picoclaw/android/core/data/remote/dto/WsIncoming.kt

@@ -7,5 +7,6 @@ import kotlinx.serialization.Serializable
 data class WsIncoming(
     val content: String,
     @SerialName("sender_id") val senderId: String? = null,
-    val images: List<String>? = null
+    val images: List<String>? = null,
+    @SerialName("input_mode") val inputMode: String? = null
 )

android/core/data/src/main/java/io/picoclaw/android/core/data/repository/ChatRepositoryImpl.kt

@@ -57,11 +57,11 @@ class ChatRepositoryImpl(
         }
     }
 
-    override suspend fun sendMessage(text: String, images: List<ImageAttachment>) {
+    override suspend fun sendMessage(text: String, images: List<ImageAttachment>, inputMode: String?) {
         val results = images.map { imageFileStorage.saveFromUri(it.uri) }
         val entity = MessageMapper.toEntity(text, results.map { it.imageData }, MessageStatus.SENDING)
         messageDao.insert(entity)
-        val wsDto = MessageMapper.toWsIncoming(text, results.map { it.base64 })
+        val wsDto = MessageMapper.toWsIncoming(text, results.map { it.base64 }, inputMode)
         val success = webSocketClient.send(wsDto)
         messageDao.update(entity.copy(status = if (success) MessageStatus.SENT.name else MessageStatus.FAILED.name))
     }

android/core/domain/src/main/java/io/picoclaw/android/core/domain/repository/ChatRepository.kt

@@ -9,7 +9,7 @@ interface ChatRepository {
     val messages: StateFlow<List<ChatMessage>>
     val connectionState: StateFlow<ConnectionState>
     val statusLabel: StateFlow<String?>
-    suspend fun sendMessage(text: String, images: List<ImageAttachment> = emptyList())
+    suspend fun sendMessage(text: String, images: List<ImageAttachment> = emptyList(), inputMode: String? = null)
     fun loadMore()
     fun connect()
     fun disconnect()

android/core/domain/src/main/java/io/picoclaw/android/core/domain/usecase/SendMessageUseCase.kt

@@ -4,7 +4,7 @@ import io.picoclaw.android.core.domain.model.ImageAttachment
 import io.picoclaw.android.core.domain.repository.ChatRepository
 
 class SendMessageUseCase(private val repository: ChatRepository) {
-    suspend operator fun invoke(text: String, images: List<ImageAttachment> = emptyList()) {
+    suspend operator fun invoke(text: String, images: List<ImageAttachment> = emptyList(), inputMode: String? = null) {
-        repository.sendMessage(text, images)
+        repository.sendMessage(text, images, inputMode)
     }
 }

android/feature/chat/src/main/java/io/picoclaw/android/feature/chat/voice/VoiceModeManager.kt

@@ -119,7 +119,7 @@ class VoiceModeManager(
                         if (!text.isNullOrBlank()) {
                             _state.update { it.copy(phase = VoicePhase.SENDING, recognizedText = text) }
                             try {
-                                sendMessage(text)
+                                sendMessage(text, inputMode = "voice")
                             } catch (e: Exception) {
                                 _state.update {
                                     it.copy(phase = VoicePhase.ERROR, errorMessage = "送信に失敗しました")

pkg/agent/context.go

@@ -190,14 +190,20 @@ func (cb *ContextBuilder) LoadBootstrapFiles() string {
 	return result
 }
 
-func (cb *ContextBuilder) BuildMessages(history []providers.Message, summary string, currentMessage string, media []string, channel, chatID string) []providers.Message {
+func (cb *ContextBuilder) BuildMessages(history []providers.Message, summary string, currentMessage string, media []string, channel, chatID, inputMode string) []providers.Message {
 	messages := []providers.Message{}
 
 	systemPrompt := cb.BuildSystemPrompt()
 
 	// Add Current Session info if provided
 	if channel != "" && chatID != "" {
-		systemPrompt += fmt.Sprintf("\n\n## Current Session\nChannel: %s\nChat ID: %s", channel, chatID)
+		systemPrompt += fmt.Sprintf("\n\n## Current Session\nChannel: %s\nChat ID: %s\nInput Mode: %s",
+			channel, chatID, inputMode)
+	}
+
+	// Add voice mode instructions when input is from voice
+	if inputMode == "voice" {
+		systemPrompt += voiceModePrompt()
 	}
 
 	// Log system prompt summary for debugging (debug mode only)

pkg/agent/loop.go

@@ -67,6 +67,7 @@ type processOptions struct {
 	EnableSummary   bool     // Whether to trigger summarization
 	SendResponse    bool     // Whether to send response via bus
 	NoHistory       bool     // If true, don't load session history (for heartbeat)
+	InputMode       string   // "voice" or "text"
 }
 
 // createToolRegistry creates a tool registry with common tools.
@@ -367,6 +368,14 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 		return response, nil
 	}
 
+	// Extract input_mode from metadata
+	inputMode := "text"
+	if msg.Metadata != nil {
+		if mode, ok := msg.Metadata["input_mode"]; ok && mode != "" {
+			inputMode = mode
+		}
+	}
+
 	// Process as user message
 	return al.runAgentLoop(ctx, processOptions{
 		SessionKey:      msg.SessionKey,
@@ -377,6 +386,7 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 		DefaultResponse: "I've completed processing but have no response to give.",
 		EnableSummary:   true,
 		SendResponse:    false,
+		InputMode:       inputMode,
 	})
 }
 
@@ -463,6 +473,7 @@ func (al *AgentLoop) runAgentLoop(ctx context.Context, opts processOptions) (str
 		opts.Media,
 		opts.Channel,
 		opts.ChatID,
+		opts.InputMode,
 	)
 
 	// 3. Save user message to session
@@ -657,6 +668,7 @@ func (al *AgentLoop) runLLMIteration(ctx context.Context, messages []providers.M
 					nil,
 					opts.Channel,
 					opts.ChatID,
+					opts.InputMode,
 				)
 
 				// Important: If we are in the middle of a tool loop (iteration > 1),
@@ -720,6 +732,7 @@ func (al *AgentLoop) runLLMIteration(ctx context.Context, messages []providers.M
 					nil,
 					opts.Channel,
 					opts.ChatID,
+					opts.InputMode,
 				)
 
 				continue

pkg/agent/voice_prompt.go

@@ -0,0 +1,16 @@
+package agent
+
+func voiceModePrompt() string {
+	return `
+
+## Voice Mode Instructions
+
+The user is currently speaking to you via voice input. Your response will be read aloud by text-to-speech.
+
+- Keep responses short and conversational (1-3 sentences by default)
+- Do NOT use markdown formatting (no headers, bold, code blocks, tables, bullet lists)
+- Use natural spoken language as if having a conversation
+- Spell out numbers and avoid special characters that sound awkward when spoken
+- If the user explicitly asks for more detail, provide longer explanations but still in natural spoken language without markdown
+- If code, file contents, or highly technical output is needed, briefly summarize and suggest switching to text mode for the full details`
+}

pkg/channels/websocket.go

@@ -16,9 +16,10 @@ import (
 
 // wsIncoming is the JSON message sent from APK to picoclaw.
 type wsIncoming struct {
-	Content  string   `json:"content"`
+	Content   string   `json:"content"`
-	SenderID string   `json:"sender_id,omitempty"`
+	SenderID  string   `json:"sender_id,omitempty"`
-	Images   []string `json:"images,omitempty"`
+	Images    []string `json:"images,omitempty"`
+	InputMode string   `json:"input_mode,omitempty"`
 }
 
 // wsOutgoing is the JSON message sent from picoclaw to APK.
@@ -252,7 +253,14 @@ func (c *WebSocketChannel) readPump(conn *websocket.Conn, clientID, chatID strin
 			"images":    len(incoming.Images),
 		})
 
-		c.HandleMessage(senderID, chatID, content, media, nil)
+		inputMode := incoming.InputMode
+		if inputMode == "" {
+			inputMode = "text"
+		}
+		metadata := map[string]string{
+			"input_mode": inputMode,
+		}
+		c.HandleMessage(senderID, chatID, content, media, metadata)
 	}
 }