fix(agent-threads): hide prompt reference directives in thread titles

Add a shared visiblePromptText helper and strip reference tokens,
image-generator directives, and model-selection lines from agent thread
summaries and the assistant panel header, so titles show the user's
actual prompt instead of internal directives. Covered by a server test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/ui/lib/promptImageReferences.ts

@@ -75,6 +75,22 @@ export function serializePromptImageReference(reference: Pick<PromptImageReferen
   return `[@image:#${fallbackIndex}:${name}:${reference.url}]`;
 }
 
+export function visiblePromptText(content: string) {
+  const text = parsePromptImageReferences(content)
+    .map((part) => (part.type === "text" ? part.text : ""))
+    .join("");
+  return text
+    .split("\n")
+    .map((line) => line.trim())
+    .filter((line) => {
+      const lower = line.toLowerCase();
+      return line && !lower.startsWith("image generator target node:") && !lower.startsWith("selected model:") && !line.startsWith("模型选择");
+    })
+    .join(" ")
+    .replace(/\s{2,}/g, " ")
+    .trim();
+}
+
 function collectReferenceMatches(content: string) {
   const matches: ReferenceMatch[] = [];
 

frontend/src/ui/pages/CanvasWorkspace/index.tsx

@@ -30,6 +30,7 @@ import { loadMotevaFontCatalog } from "@/ui/components/TextStyleToolbar/fontCata
 import { WorkspaceTitle } from "@/ui/components/WorkspaceTitle";
 import { autoImageAdjustments, defaultImageAdjustments, parseImageAdjustments, serializeImageAdjustments } from "@/ui/lib/imageAdjustments";
 import { canvasImageUrl } from "@/ui/lib/imageDelivery";
+import { visiblePromptText } from "@/ui/lib/promptImageReferences";
 import { isImageGeneratorThreadMessage, visibleAgentMessages } from "./canvas/agentMessageFilters";
 import { CanvasColorPopover } from "./canvas/CanvasColorPopover";
 import { buildAlignmentGuides, clamp, minGroupNodeScale, nodeBounds, nodeIntersectsRect, normalizeScreenRect, pointInsideNode, scaleGroupNode, screenBoundsForNodes, screenRectToWorldRect, type AlignmentGuide, type NodeAlignment, type NodeDistribution, type NodeTransform, type ResizeHandle, type SelectionBox } from "@/ui/pages/CanvasWorkspace/canvas/canvasGeometry";
@@ -3756,7 +3757,7 @@ export function CanvasWorkspace({ projectId }: { projectId: string }) {
           <aside className="assistant-panel">
           <div className="assistant-header">
             <div className="assistant-header-title">
-              <strong>{project.brief || project.title || t("canvasUntitled")}</strong>
+              <strong>{agentHeaderTitle(messages, project, t("canvasUntitled"))}</strong>
             </div>
             <div className="assistant-header-actions">
               <button className="assistant-header-icon" type="button" aria-label={t("newChat")} title={t("newChat")} onClick={beginNewAgentConversation} disabled={!hasCurrentConversation}>
@@ -5289,7 +5290,7 @@ function fallbackAgentThreads(project: Project | null, hiddenThreadIds: Readonly
 }
 
 function agentThreadTitle(thread: AgentThreadSummary) {
-  return thread.text.trim() || "新对话";
+  return visiblePromptText(thread.text) || "新对话";
 }
 
 function latestAgentThreadId(project: Project | null, hiddenThreadIds: ReadonlySet<string>) {
@@ -5298,14 +5299,14 @@ function latestAgentThreadId(project: Project | null, hiddenThreadIds: ReadonlyS
 }
 
 function agentThreadTitleText(content: string) {
-  const lines = content
-    .split("\n")
-    .map((line) => line.trim())
-    .filter((line) => {
-      const lower = line.toLowerCase();
-      return line && !lower.startsWith("image generator target node:") && !lower.startsWith("selected model:") && !line.startsWith("模型选择");
-    });
-  return lines.join(" ").trim() || content.trim();
+  return visiblePromptText(content);
+}
+
+function agentHeaderTitle(messages: AgentMessage[], project: Project, fallback: string) {
+  const firstUserMessage = messages.find((message) => message.role === "user");
+  const firstUserText = firstUserMessage ? visiblePromptText(firstUserMessage.content) : "";
+  if (firstUserText) return firstUserText;
+  return visiblePromptText(project.brief) || project.title.trim() || fallback;
 }
 
 function isProjectGenerating(project: Project) {

server/internal/application/agent_threads_test.go

@@ -44,6 +44,44 @@ func TestAgentThreadsOnlyListsAgentConversationThreads(t *testing.T) {
 	}
 }
 
+func TestAgentThreadsSummaryHidesPromptReferenceDirectives(t *testing.T) {
+	ctx := context.Background()
+	repo := memory.NewProjectRepository()
+	service := NewDesignService(repo, nil, nil, nil, nil)
+	now := time.Now()
+	project := design.Project{
+		ID:           "project-agent-reference-history",
+		Title:        "Agent history",
+		Status:       design.StatusReady,
+		LastThreadID: "thread-agent",
+		UpdatedAt:    now,
+		Messages: []design.Message{
+			{
+				ID:        "agent-user",
+				Role:      "user",
+				Type:      "user",
+				Content:   "Reference image 1 (image): http://localhost:19000/canvas-assets/reference.png 灰裤子拆成单件衣服，为了后面电商配图。\nSelected model: GPT Image 2",
+				ThreadID:  "thread-agent",
+				CreatedAt: now,
+			},
+		},
+	}
+	if err := repo.Save(ctx, project); err != nil {
+		t.Fatal(err)
+	}
+
+	threads, err := service.AgentThreads(ctx, project.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(threads) != 1 {
+		t.Fatalf("expected one agent thread, got %#v", threads)
+	}
+	if threads[0].Text != "灰裤子拆成单件衣服，为了后面电商配图。" {
+		t.Fatalf("expected visible prompt text only, got %q", threads[0].Text)
+	}
+}
+
 func TestProjectScopedToAgentThreadKeepsOnlyCurrentConversationContext(t *testing.T) {
 	now := time.Now()
 	project := design.Project{

server/internal/application/design_service.go

@@ -824,6 +824,7 @@ func isNonAgentConversationMessage(message design.Message) bool {
 }
 
 func agentThreadSummaryText(content string) string {
+	content = stripPromptReferenceDirectives(content)
 	lines := strings.Split(content, "\n")
 	kept := make([]string, 0, len(lines))
 	for _, line := range lines {
@@ -837,7 +838,7 @@ func agentThreadSummaryText(content string) string {
 	if text := strings.TrimSpace(strings.Join(kept, " ")); text != "" {
 		return text
 	}
-	return strings.TrimSpace(content)
+	return ""
 }
 
 func projectScopedToAgentThread(project design.Project, threadID string) design.Project {
@@ -4530,7 +4531,7 @@ func hasUserPromptTextInAgentMessages(messages []design.AgentChatMessage) bool {
 			if strings.EqualFold(strings.TrimSpace(content.TextSource), "settings") {
 				continue
 			}
-			text := stripPromptReferenceDirectiveLines(stripImageGeneratorDirectiveLines(content.Text))
+			text := stripPromptReferenceDirectives(stripImageGeneratorDirectiveLines(content.Text))
 			if design.NormalizePrompt(text) != "" {
 				return true
 			}
@@ -4551,12 +4552,14 @@ func stripImageGeneratorDirectiveLines(text string) string {
 	return strings.TrimSpace(strings.Join(filtered, "\n"))
 }
 
-func stripPromptReferenceDirectiveLines(text string) string {
+func stripPromptReferenceDirectives(text string) string {
+	text = promptImageTokenPattern.ReplaceAllString(text, "")
+	text = promptImageDirectivePattern.ReplaceAllString(text, "")
 	lines := strings.Split(text, "\n")
 	filtered := make([]string, 0, len(lines))
 	for _, line := range lines {
 		trimmed := strings.TrimSpace(strings.ReplaceAll(line, "\u00a0", " "))
-		if isPromptReferenceDirectiveLine(trimmed) {
+		if trimmed == "" || isPromptReferenceDirectiveLine(trimmed) {
 			continue
 		}
 		filtered = append(filtered, line)