diff --git a/frontend/src/components/workspace/messages/feedback-dialog.tsx b/frontend/src/components/workspace/messages/feedback-dialog.tsx
new file mode 100644
index 000000000..4ca8a740c
--- /dev/null
+++ b/frontend/src/components/workspace/messages/feedback-dialog.tsx
@@ -0,0 +1,113 @@
+"use client";
+
+import { useState } from "react";
+
+import { FEEDBACK_TAG_SLUGS, type FeedbackTagSlug } from "@/core/api/feedback";
+import { useI18n } from "@/core/i18n/hooks";
+import { cn } from "@/lib/utils";
+
+import { Button } from "../../ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "../../ui/dialog";
+import { Textarea } from "../../ui/textarea";
+
+/** Maps language-neutral tag slugs to their i18n label keys. */
+const TAG_LABEL_KEYS: Record<FeedbackTagSlug, "incorrect" | "notAsExpected" | "slow" | "styleTone" | "safetyLegal" | "other"> = {
+  incorrect: "incorrect",
+  not_as_expected: "notAsExpected",
+  slow: "slow",
+  style_tone: "styleTone",
+  safety_legal: "safetyLegal",
+  other: "other",
+};
+
+/**
+ * Thumbs-down follow-up dialog (ChatGPT-style): reason chips + optional
+ * details. The rating itself is already stored when this opens; submitting
+ * issues a second idempotent PUT that enriches the same record with
+ * tags/comment. Closing without submitting keeps the plain thumbs-down.
+ */
+export function FeedbackDialog({
+  open,
+  onOpenChange,
+  onSubmit,
+}: {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  onSubmit: (tags: string[], comment: string) => Promise<void>;
+}) {
+  const { t } = useI18n();
+  const [selected, setSelected] = useState<Set<FeedbackTagSlug>>(new Set());
+  const [comment, setComment] = useState("");
+  const [isSubmitting, setIsSubmitting] = useState(false);
+
+  const toggleTag = (slug: FeedbackTagSlug) => {
+    setSelected((prev) => {
+      const next = new Set(prev);
+      if (next.has(slug)) {
+        next.delete(slug);
+      } else {
+        next.add(slug);
+      }
+      return next;
+    });
+  };
+
+  const canSubmit = (selected.size > 0 || comment.trim().length > 0) && !isSubmitting;
+
+  const handleSubmit = async () => {
+    if (!canSubmit) return;
+    setIsSubmitting(true);
+    try {
+      await onSubmit([...selected], comment.trim());
+      onOpenChange(false);
+      setSelected(new Set());
+      setComment("");
+    } finally {
+      setIsSubmitting(false);
+    }
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="sm:max-w-lg">
+        <DialogHeader>
+          <DialogTitle>{t.feedback.dialogTitle}</DialogTitle>
+        </DialogHeader>
+        <div className="flex flex-wrap gap-2">
+          {FEEDBACK_TAG_SLUGS.map((slug) => (
+            <button
+              key={slug}
+              type="button"
+              onClick={() => toggleTag(slug)}
+              className={cn(
+                "rounded-full border px-3 py-1.5 text-sm transition-colors",
+                selected.has(slug)
+                  ? "border-foreground bg-foreground text-background"
+                  : "border-border text-foreground hover:bg-muted",
+              )}
+            >
+              {t.feedback.tags[TAG_LABEL_KEYS[slug]]}
+            </button>
+          ))}
+        </div>
+        <Textarea
+          value={comment}
+          onChange={(event) => setComment(event.target.value)}
+          placeholder={t.feedback.detailsPlaceholder}
+          rows={4}
+        />
+        <DialogFooter>
+          <Button type="button" onClick={handleSubmit} disabled={!canSubmit}>
+            {t.feedback.submit}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/frontend/src/components/workspace/messages/message-list-item.tsx b/frontend/src/components/workspace/messages/message-list-item.tsx
index 0b28bfc2a..f3e9d7f03 100644
--- a/frontend/src/components/workspace/messages/message-list-item.tsx
+++ b/frontend/src/components/workspace/messages/message-list-item.tsx
@@ -60,10 +60,11 @@ import { CopyButton } from "../copy-button";
 import { ReferenceAttachmentSummary } from "../sidecar/reference-attachments";
 import { SlashSkillChip } from "../slash-skill-chip";
 
+import { FeedbackDialog } from "./feedback-dialog";
 import { MarkdownContent } from "./markdown-content";
 import { createMarkdownLinkComponent } from "./markdown-link";
 
-function FeedbackButtons({
+export function FeedbackButtons({
   threadId,
   runId,
   initialFeedback,
@@ -72,22 +73,32 @@ function FeedbackButtons({
   runId: string;
   initialFeedback: FeedbackData | null;
 }) {
+  const { t } = useI18n();
   const [feedback, setFeedback] = useState<FeedbackData | null>(
     initialFeedback,
   );
   const [isSubmitting, setIsSubmitting] = useState(false);
+  const [dialogOpen, setDialogOpen] = useState(false);
 
+  // Strict mutual exclusion: once a rating exists, only its own (highlighted)
+  // button stays visible; the user must retract it before rating the other
+  // way. No direct up<->down switching.
   const handleClick = useCallback(
     async (rating: number) => {
       if (isSubmitting) return;
       setIsSubmitting(true);
       try {
-        if (feedback?.rating === rating) {
+        if (feedback) {
+          // Only the active button is rendered, so this is always a retract.
           await deleteFeedback(threadId, runId);
           setFeedback(null);
         } else {
           const result = await upsertFeedback(threadId, runId, rating);
           setFeedback(result);
+          if (rating === -1) {
+            // Rating is already stored; the dialog only enriches it.
+            setDialogOpen(true);
+          }
         }
       } catch {
         // Revert on error — feedback state unchanged on catch
@@ -98,34 +109,59 @@ function FeedbackButtons({
     [threadId, runId, feedback, isSubmitting],
   );
 
+  const handleDialogSubmit = useCallback(
+    async (tags: string[], comment: string) => {
+      const result = await upsertFeedback(
+        threadId,
+        runId,
+        -1,
+        comment.length > 0 ? comment : undefined,
+        tags,
+      );
+      setFeedback(result);
+    },
+    [threadId, runId],
+  );
+
   return (
     <div className="flex gap-1">
-      <button
-        type="button"
-        className={cn(
-          "text-muted-foreground hover:text-foreground rounded-md p-1 transition-colors",
-          feedback?.rating === 1 && "text-foreground",
-        )}
-        onClick={() => handleClick(1)}
-        disabled={isSubmitting}
-      >
-        <ThumbsUpIcon
-          className={cn("size-4", feedback?.rating === 1 && "fill-current")}
-        />
-      </button>
-      <button
-        type="button"
-        className={cn(
-          "text-muted-foreground hover:text-foreground rounded-md p-1 transition-colors",
-          feedback?.rating === -1 && "text-foreground",
-        )}
-        onClick={() => handleClick(-1)}
-        disabled={isSubmitting}
-      >
-        <ThumbsDownIcon
-          className={cn("size-4", feedback?.rating === -1 && "fill-current")}
-        />
-      </button>
+      {(!feedback || feedback.rating === 1) && (
+        <button
+          type="button"
+          aria-label={t.feedback.thumbsUp}
+          className={cn(
+            "text-muted-foreground hover:text-foreground rounded-md p-1 transition-colors",
+            feedback?.rating === 1 && "text-foreground",
+          )}
+          onClick={() => handleClick(1)}
+          disabled={isSubmitting}
+        >
+          <ThumbsUpIcon
+            className={cn("size-4", feedback?.rating === 1 && "fill-current")}
+          />
+        </button>
+      )}
+      {(!feedback || feedback.rating === -1) && (
+        <button
+          type="button"
+          aria-label={t.feedback.thumbsDown}
+          className={cn(
+            "text-muted-foreground hover:text-foreground rounded-md p-1 transition-colors",
+            feedback?.rating === -1 && "text-foreground",
+          )}
+          onClick={() => handleClick(-1)}
+          disabled={isSubmitting}
+        >
+          <ThumbsDownIcon
+            className={cn("size-4", feedback?.rating === -1 && "fill-current")}
+          />
+        </button>
+      )}
+      <FeedbackDialog
+        open={dialogOpen}
+        onOpenChange={setDialogOpen}
+        onSubmit={handleDialogSubmit}
+      />
     </div>
   );
 }
diff --git a/frontend/src/components/workspace/messages/message-list.tsx b/frontend/src/components/workspace/messages/message-list.tsx
index b1591a5ad..a023ed024 100644
--- a/frontend/src/components/workspace/messages/message-list.tsx
+++ b/frontend/src/components/workspace/messages/message-list.tsx
@@ -28,6 +28,7 @@ import {
   ReasoningTrigger,
 } from "@/components/ai-elements/reasoning";
 import { Button } from "@/components/ui/button";
+import type { FeedbackData } from "@/core/api/feedback";
 import { extractArtifactsFromThread } from "@/core/artifacts/utils";
 import { useI18n } from "@/core/i18n/hooks";
 import {
@@ -83,7 +84,7 @@ import {
 } from "./human-input-card";
 import { MarkdownContent } from "./markdown-content";
 import { MessageGroup } from "./message-group";
-import { MessageListItem } from "./message-list-item";
+import { FeedbackButtons, MessageListItem } from "./message-list-item";
 import {
   MessageTokenUsageDebugList,
   MessageTokenUsageList,
@@ -738,10 +739,26 @@ export function MessageList({
       if (!clipboardData && !actionTarget) {
         return null;
       }
+      // Feedback echoes back on the run's last AI message (attached by the
+      // message-list endpoints); the turn's action bar owns the thumbs.
+      const feedbackTarget = actionTarget as
+        | { run_id?: string; feedback?: FeedbackData | null }
+        | undefined;
+      const feedbackRunId =
+        typeof feedbackTarget?.run_id === "string"
+          ? feedbackTarget.run_id
+          : undefined;
 
       return (
         <div className="mt-2 flex justify-start gap-1 opacity-0 transition-opacity delay-200 duration-300 group-hover/assistant-turn:opacity-100">
           {clipboardData && <CopyButton clipboardData={clipboardData} />}
+          {!isStreaming && feedbackRunId && (
+            <FeedbackButtons
+              threadId={threadId}
+              runId={feedbackRunId}
+              initialFeedback={feedbackTarget?.feedback ?? null}
+            />
+          )}
           {enableBranchForTurn &&
             !isStreaming &&
             actionTarget?.id &&
@@ -824,6 +841,7 @@ export function MessageList({
       regeneratingMessageId,
       t.common.branch,
       t.common.regenerate,
+      threadId,
     ],
   );
 
diff --git a/frontend/src/core/api/feedback.ts b/frontend/src/core/api/feedback.ts
index bc6021d95..34a34787e 100644
--- a/frontend/src/core/api/feedback.ts
+++ b/frontend/src/core/api/feedback.ts
@@ -6,20 +6,38 @@ export interface FeedbackData {
   feedback_id: string;
   rating: number;
   comment: string | null;
+  tags?: string[];
 }
 
+/** Language-neutral thumbs-down reason slugs; must match the backend's
+ *  VALID_FEEDBACK_TAGS (deerflow.domain.feedback.model). */
+export const FEEDBACK_TAG_SLUGS = [
+  "incorrect",
+  "not_as_expected",
+  "slow",
+  "style_tone",
+  "safety_legal",
+  "other",
+] as const;
+export type FeedbackTagSlug = (typeof FEEDBACK_TAG_SLUGS)[number];
+
 export async function upsertFeedback(
   threadId: string,
   runId: string,
   rating: number,
   comment?: string,
+  tags?: string[],
 ): Promise<FeedbackData> {
   const res = await fetch(
     `${getBackendBaseURL()}/api/threads/${encodeURIComponent(threadId)}/runs/${encodeURIComponent(runId)}/feedback`,
     {
       method: "PUT",
       headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ rating, comment: comment ?? null }),
+      body: JSON.stringify({
+        rating,
+        comment: comment ?? null,
+        tags: tags ?? [],
+      }),
     },
   );
   if (!res.ok) {
diff --git a/frontend/src/core/i18n/locales/en-US.ts b/frontend/src/core/i18n/locales/en-US.ts
index c9fa25538..05df77eca 100644
--- a/frontend/src/core/i18n/locales/en-US.ts
+++ b/frontend/src/core/i18n/locales/en-US.ts
@@ -18,6 +18,21 @@ export const enUS: Translations = {
   },
 
   // Common
+  feedback: {
+    thumbsUp: "Good response",
+    thumbsDown: "Bad response",
+    dialogTitle: "Share feedback",
+    detailsPlaceholder: "Share more details (optional)",
+    submit: "Submit",
+    tags: {
+      incorrect: "Incorrect or incomplete",
+      notAsExpected: "Not what I expected",
+      slow: "Slow or had issues",
+      styleTone: "Style or tone",
+      safetyLegal: "Safety or legal concern",
+      other: "Other",
+    },
+  },
   common: {
     home: "Home",
     settings: "Settings",
diff --git a/frontend/src/core/i18n/locales/types.ts b/frontend/src/core/i18n/locales/types.ts
index 0931cd54e..470a42356 100644
--- a/frontend/src/core/i18n/locales/types.ts
+++ b/frontend/src/core/i18n/locales/types.ts
@@ -7,6 +7,21 @@ export interface Translations {
   };
 
   // Common
+  feedback: {
+    thumbsUp: string;
+    thumbsDown: string;
+    dialogTitle: string;
+    detailsPlaceholder: string;
+    submit: string;
+    tags: {
+      incorrect: string;
+      notAsExpected: string;
+      slow: string;
+      styleTone: string;
+      safetyLegal: string;
+      other: string;
+    };
+  };
   common: {
     home: string;
     settings: string;
diff --git a/frontend/src/core/i18n/locales/zh-CN.ts b/frontend/src/core/i18n/locales/zh-CN.ts
index 16f653aef..68f229dca 100644
--- a/frontend/src/core/i18n/locales/zh-CN.ts
+++ b/frontend/src/core/i18n/locales/zh-CN.ts
@@ -18,6 +18,21 @@ export const zhCN: Translations = {
   },
 
   // Common
+  feedback: {
+    thumbsUp: "点赞",
+    thumbsDown: "点踩",
+    dialogTitle: "分享反馈",
+    detailsPlaceholder: "分享详细信息（可选）",
+    submit: "提交",
+    tags: {
+      incorrect: "不正确或不完整",
+      notAsExpected: "与期望不符",
+      slow: "速度慢或存在问题",
+      styleTone: "风格或语气",
+      safetyLegal: "安全或法律疑虑",
+      other: "其他",
+    },
+  },
   common: {
     home: "首页",
     settings: "设置",