feat: implement auto generate title logic for conversations

backend/internal/application/conversation/service_metadata.go

@@ -14,8 +14,10 @@ import (
 )
 
 const (
-	conversationMetadataMessageMaxTokens = int64(5000)
-	conversationMetadataTitlePrompt      = `Generate a concise title from the first conversation turn below. Return ONLY a valid JSON object.
+	conversationMetadataMessageMaxTokens    = int64(5000)
+	conversationFirstMessageTitleMaxRunes   = 20
+	conversationAutoGenerateTitleSettingKey = "chat.auto_generate_title"
+	conversationMetadataTitlePrompt         = `Generate a concise title from the first conversation turn below. Return ONLY a valid JSON object.
 
 ## Constraints
 1. **Content**: Reflect the primary topic, goal, or main subject.
@@ -72,9 +74,6 @@ func (s *Service) maybeGenerateConversationMetadataAsync(conversation model.Conv
 }
 
 func (s *Service) generateConversationMetadata(ctx context.Context, conversation model.Conversation, userMsg model.Message, assistantMsg model.Message) (*model.Conversation, error) {
-	if s.routeResolver == nil || s.llmClient == nil {
-		return nil, nil
-	}
 	cfg := s.cfg.Snapshot()
 	messages := buildConversationMetadataMessages(userMsg, assistantMsg)
 
@@ -95,7 +94,13 @@ func (s *Service) generateConversationMetadata(ctx context.Context, conversation
 		}
 	}
 
-	if shouldAutoReplaceConversationTitle(conversation.Title) {
+	shouldReplaceTitle := shouldAutoReplaceConversationTitle(conversation.Title)
+	shouldGenerateTitle := shouldReplaceTitle && s.autoGenerateConversationTitleEnabled(ctx, conversation.UserID)
+	if shouldReplaceTitle && !shouldGenerateTitle {
+		title = conversationTitleFromFirstUserMessage(userMsg.Content)
+	}
+
+	if s.routeResolver != nil && s.llmClient != nil && shouldGenerateTitle {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
@@ -112,29 +117,31 @@ func (s *Service) generateConversationMetadata(ctx context.Context, conversation
 		}()
 	}
 
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		labelsPrompt := renderConversationMetadataPrompt(cfg.ConversationLabelsPrompt, conversationMetadataLabelsPrompt, messages)
-		labelsOut, err := s.callConversationMetadataLLM(ctx, cfg.ConversationTaskModel, conversation.Model, conversation.UserID, conversation.ID, labelsPrompt)
-		if err != nil {
-			setGenerateErr(err)
-			return
-		}
-		s.recordBasicServiceUsage(ctx, conversation.UserID, conversation.ID, "labels", "标签", labelsOut.PlatformModelName, labelsOut.RoutedBindingCode, labelsOut.ProviderProtocol, labelsOut.UpstreamName, labelsOut.UpstreamModel, "5m", labelsOut.Usage, labelsOut.Messages, labelsOut.Text, labelsOut.LatencyMS)
-		labels := sanitizeGeneratedConversationLabels(parseGeneratedConversationLabels(labelsOut.Text))
-		if len(labels) == 0 {
-			return
-		}
-		raw, marshalErr := json.Marshal(labels)
-		if marshalErr != nil {
-			setGenerateErr(marshalErr)
-			return
-		}
-		mu.Lock()
-		labelsJSON = string(raw)
-		mu.Unlock()
-	}()
+	if s.routeResolver != nil && s.llmClient != nil {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			labelsPrompt := renderConversationMetadataPrompt(cfg.ConversationLabelsPrompt, conversationMetadataLabelsPrompt, messages)
+			labelsOut, err := s.callConversationMetadataLLM(ctx, cfg.ConversationTaskModel, conversation.Model, conversation.UserID, conversation.ID, labelsPrompt)
+			if err != nil {
+				setGenerateErr(err)
+				return
+			}
+			s.recordBasicServiceUsage(ctx, conversation.UserID, conversation.ID, "labels", "标签", labelsOut.PlatformModelName, labelsOut.RoutedBindingCode, labelsOut.ProviderProtocol, labelsOut.UpstreamName, labelsOut.UpstreamModel, "5m", labelsOut.Usage, labelsOut.Messages, labelsOut.Text, labelsOut.LatencyMS)
+			labels := sanitizeGeneratedConversationLabels(parseGeneratedConversationLabels(labelsOut.Text))
+			if len(labels) == 0 {
+				return
+			}
+			raw, marshalErr := json.Marshal(labels)
+			if marshalErr != nil {
+				setGenerateErr(marshalErr)
+				return
+			}
+			mu.Lock()
+			labelsJSON = string(raw)
+			mu.Unlock()
+		}()
+	}
 
 	wg.Wait()
 	mu.Lock()
@@ -388,6 +395,19 @@ func sanitizeGeneratedConversationTitle(raw string) string {
 	return strings.TrimSpace(value)
 }
 
+func conversationTitleFromFirstUserMessage(content string) string {
+	value := strings.Join(strings.Fields(strings.TrimSpace(content)), " ")
+	value = strings.Trim(value, " \t\r\n\"'`“”‘’")
+	if value == "" {
+		return ""
+	}
+	runes := []rune(value)
+	if len(runes) > conversationFirstMessageTitleMaxRunes {
+		value = string(runes[:conversationFirstMessageTitleMaxRunes])
+	}
+	return strings.TrimSpace(value)
+}
+
 func sanitizeGeneratedConversationLabels(raw []string) []string {
 	seen := make(map[string]struct{}, len(raw))
 	labels := make([]string, 0, len(raw))
@@ -414,6 +434,17 @@ func sanitizeGeneratedConversationLabels(raw []string) []string {
 	return labels
 }
 
+func (s *Service) autoGenerateConversationTitleEnabled(ctx context.Context, userID uint) bool {
+	value, err := s.repo.GetUserSettingValue(ctx, userID, conversationAutoGenerateTitleSettingKey)
+	if err != nil {
+		if s.logger != nil {
+			s.logger.Warn("conversation_title_setting_load_failed", zap.Uint("user_id", userID), zap.Error(err))
+		}
+		return true
+	}
+	return strings.TrimSpace(strings.ToLower(value)) != "false"
+}
+
 func shouldAutoReplaceConversationTitle(title string) bool {
 	value := strings.TrimSpace(strings.ToLower(title))
 	switch value {

backend/internal/application/conversation/service_metadata_test.go

@@ -57,3 +57,17 @@ func TestParseGeneratedConversationTitleRejectsDirtyOutput(t *testing.T) {
 		}
 	}
 }
+
+func TestConversationTitleFromFirstUserMessage(t *testing.T) {
+	cases := map[string]string{
+		"  这是一条很长的第一条用户消息，用来测试标题截断  ":        "这是一条很长的第一条用户消息，用来测试标",
+		"\n\nhello   world   from   DEEIX\n": "hello world from DEE",
+		"\"简短标题\"":                           "简短标题",
+		"   ":                                "",
+	}
+	for input, want := range cases {
+		if got := conversationTitleFromFirstUserMessage(input); got != want {
+			t.Fatalf("unexpected first-message title for %q: got %q, want %q", input, got, want)
+		}
+	}
+}

backend/internal/application/usersettings/service.go

@@ -27,6 +27,7 @@ var allowedKeys = map[string]string{
 	"chat.show_latency":                 "true",
 	"chat.show_billing_cost":            "true",
 	"chat.default_model":                "",
+	"chat.auto_generate_title":          "true",
 	"chat.context_compact_auto":         "true",
 	"chat.markdown_render":              "true",
 	"chat.restore_draft_on_failure":     "true",
@@ -40,6 +41,7 @@ var boolKeys = map[string]bool{
 	"chat.show_model_info":              true,
 	"chat.show_latency":                 true,
 	"chat.show_billing_cost":            true,
+	"chat.auto_generate_title":          true,
 	"chat.context_compact_auto":         true,
 	"chat.markdown_render":              true,
 	"chat.restore_draft_on_failure":     true,

frontend/features/chat/hooks/use-chat-message-submit.ts

@@ -130,8 +130,13 @@ function normalizeLabelsJSON(value: string | null | undefined): string {
   return normalized && normalized !== "null" ? normalized : "[]";
 }
 
-function shouldRefreshGeneratedConversationMetadata(item: ConversationDTO | null): boolean {
-  return item !== null && item.messageCount === 0;
+function isPlaceholderConversationTitle(title: string): boolean {
+  const value = title.trim().toLowerCase();
+  return ["", "new conversation", "untitled", "新会话", "新对话", "新的对话"].includes(value);
+}
+
+function shouldRefreshGeneratedConversationMetadata(item: ConversationDTO | null, visibleMessageCount: number): boolean {
+  return visibleMessageCount === 0 || item?.messageCount === 0;
 }
 
 function hasGeneratedConversationMetadataChanged(
@@ -140,7 +145,7 @@ function hasGeneratedConversationMetadataChanged(
 ): boolean {
   const previousTitle = previous?.title?.trim() ?? "";
   const nextTitle = next.title.trim();
-  if (nextTitle && nextTitle !== previousTitle) {
+  if (nextTitle && nextTitle !== previousTitle && !isPlaceholderConversationTitle(nextTitle)) {
     return true;
   }
   return normalizeLabelsJSON(next.labelsJSON) !== normalizeLabelsJSON(previous?.labelsJSON);
@@ -424,7 +429,7 @@ export function useChatMessageSubmit({
           window.history.replaceState(null, "", `/chat?conversation_id=${created.publicID}`);
           onConversationCreated?.(created.publicID);
         }
-        const shouldRefreshConversationMetadata = shouldRefreshGeneratedConversationMetadata(targetConversation);
+        const shouldRefreshConversationMetadata = shouldRefreshGeneratedConversationMetadata(targetConversation, visibleMessageCount);
 
         const commonStreamPayload = {
           model: requestPlatformModelName,

frontend/features/settings/components/sections/settings-chat.tsx

@@ -456,6 +456,19 @@ export function SettingsChat() {
               />
             )}
           </SettingsFieldRow>
+          <div className="pt-4">
+            <SettingsFieldRow
+              title={t("defaultModel.autoTitle")}
+              description={t("defaultModel.autoTitleDescription")}
+            >
+              <Switch
+                checked={settings.autoGenerateTitle}
+                onCheckedChange={handleBool("chat.auto_generate_title", "autoGenerateTitle")}
+                disabled={loading}
+                aria-label={t("defaultModel.autoTitle")}
+              />
+            </SettingsFieldRow>
+          </div>
         </SettingsFieldList>
       </SettingsSection>
 

frontend/features/settings/types/settings.ts

@@ -15,6 +15,7 @@ export type ChatSettings = {
   showLatency: boolean;
   showBillingCost: boolean;
   markdownRender: boolean;
+  autoGenerateTitle: boolean;
   contextCompactAuto: boolean;
   restoreDraftOnFailure: boolean;
   preserveConversationDrafts: boolean;

frontend/features/settings/utils/chat-settings.ts

@@ -15,6 +15,7 @@ export const DEFAULT_CHAT_SETTINGS: ChatSettings = {
   showLatency: true,
   showBillingCost: true,
   markdownRender: true,
+  autoGenerateTitle: true,
   contextCompactAuto: false,
   restoreDraftOnFailure: true,
   preserveConversationDrafts: true,
@@ -35,6 +36,7 @@ export function parseChatSettings(map: UserSettingsMap): ChatSettings {
     showLatency: map["chat.show_latency"] !== "false",
     showBillingCost: map["chat.show_billing_cost"] !== "false",
     markdownRender: map["chat.markdown_render"] !== "false",
+    autoGenerateTitle: map["chat.auto_generate_title"] !== "false",
     contextCompactAuto: map["chat.context_compact_auto"] === "true",
     restoreDraftOnFailure: map["chat.restore_draft_on_failure"] !== "false",
     preserveConversationDrafts: map["chat.preserve_conversation_drafts"] !== "false",

frontend/i18n/messages/en-US/settings.json

@@ -346,7 +346,9 @@
       "sectionTitle": "Default model",
       "title": "Default model for new chats",
       "description": "The model preselected for new chats. Leave empty to use the first available system-recommended model.",
-      "systemRecommended": "System default"
+      "systemRecommended": "System default",
+      "autoTitle": "Auto-generate titles",
+      "autoTitleDescription": "When disabled, new chats use the first 20 characters of the first message as the title."
     },
     "input": {
       "sectionTitle": "Input and sending",

frontend/i18n/messages/zh-CN/settings.json

@@ -346,7 +346,9 @@
       "sectionTitle": "默认模型",
       "title": "新会话默认模型",
       "description": "开启新对话时预选的模型。留空则使用系统推荐的第一个可用模型。",
-      "systemRecommended": "系统默认"
+      "systemRecommended": "系统默认",
+      "autoTitle": "自动生成标题",
+      "autoTitleDescription": "关闭后，新对话使用第一条消息的前 20 个字符作为标题。"
     },
     "input": {
       "sectionTitle": "输入与发送",