diff --git a/src/app/page.tsx b/src/app/page.tsx
index 220b35e..7075700 100644
--- a/src/app/page.tsx
+++ b/src/app/page.tsx
@@ -587,7 +587,7 @@ export default function Home() {
                 OpenClaw Task Hub
               </h1>
               <p className="text-xs md:text-sm text-slate-400 mt-1">
-                Track ideas, tasks, bugs, and plans — with threaded notes
+                Track ideas, tasks, bugs, and plans — with threaded comments
               </p>
             </div>
             <div className="flex items-center gap-3">
@@ -1155,13 +1155,13 @@ export default function Home() {
                 <div className="border-t border-slate-800 pt-6">
                   <h4 className="font-medium text-white mb-4 flex items-center gap-2">
                     <MessageSquare className="w-4 h-4" />
-                    Notes & Comments ({editedTask.comments?.length || 0})
+                    Comments ({editedTask.comments?.length || 0})
                   </h4>
 
                   {/* Comment List */}
                   <div className="space-y-4 mb-4">
                     {!editedTask.comments || editedTask.comments.length === 0 ? (
-                      <p className="text-slate-500 text-sm">No notes yet. Add the first one!</p>
+                      <p className="text-slate-500 text-sm">No comments yet. Add the first one.</p>
                     ) : (
                       editedTask.comments.map((comment) => (
                         <div
@@ -1208,7 +1208,7 @@ export default function Home() {
                     <Textarea
                       value={newComment}
                       onChange={(e) => setNewComment(e.target.value)}
-                      placeholder="Add a note or comment..."
+                      placeholder="Add a comment..."
                       className="flex-1 bg-slate-800 border-slate-700 text-white placeholder-slate-500"
                       rows={2}
                       onKeyDown={(e) => {
diff --git a/src/app/tasks/[taskId]/page.tsx b/src/app/tasks/[taskId]/page.tsx
index fca01ef..3bfac50 100644
--- a/src/app/tasks/[taskId]/page.tsx
+++ b/src/app/tasks/[taskId]/page.tsx
@@ -7,7 +7,15 @@ import { Badge } from "@/components/ui/badge"
 import { Button } from "@/components/ui/button"
 import { Label } from "@/components/ui/label"
 import { Textarea } from "@/components/ui/textarea"
-import { useTaskStore, type Priority, type Task, type TaskAttachment, type TaskStatus, type TaskType } from "@/stores/useTaskStore"
+import {
+  useTaskStore,
+  type Comment as TaskComment,
+  type Priority,
+  type Task,
+  type TaskAttachment,
+  type TaskStatus,
+  type TaskType,
+} from "@/stores/useTaskStore"
 
 const typeColors: Record<TaskType, string> = {
   idea: "bg-purple-500",
@@ -53,6 +61,60 @@ const getAttachments = (taskLike: { attachments?: unknown }) => {
   })
 }
 
+const getComments = (value: unknown): TaskComment[] => {
+  if (!Array.isArray(value)) return []
+
+  return value
+    .map((entry) => {
+      if (!entry || typeof entry !== "object") return null
+      const comment = entry as Partial<TaskComment>
+      if (typeof comment.id !== "string" || typeof comment.text !== "string") return null
+
+      return {
+        id: comment.id,
+        text: comment.text,
+        createdAt: typeof comment.createdAt === "string" ? comment.createdAt : new Date().toISOString(),
+        author: comment.author === "assistant" ? "assistant" : "user",
+        replies: getComments(comment.replies),
+      }
+    })
+    .filter((comment): comment is TaskComment => comment !== null)
+}
+
+const buildComment = (text: string, author: "user" | "assistant" = "user"): TaskComment => ({
+  id: `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
+  text,
+  createdAt: new Date().toISOString(),
+  author,
+  replies: [],
+})
+
+const addReplyToThread = (comments: TaskComment[], parentId: string, reply: TaskComment): TaskComment[] =>
+  comments.map((comment) => {
+    if (comment.id === parentId) {
+      return {
+        ...comment,
+        replies: [...getComments(comment.replies), reply],
+      }
+    }
+
+    return {
+      ...comment,
+      replies: addReplyToThread(getComments(comment.replies), parentId, reply),
+    }
+  })
+
+const removeCommentFromThread = (comments: TaskComment[], targetId: string): TaskComment[] =>
+  comments
+    .filter((comment) => comment.id !== targetId)
+    .map((comment) => ({
+      ...comment,
+      replies: removeCommentFromThread(getComments(comment.replies), targetId),
+    }))
+
+const countThreadComments = (comments: TaskComment[]): number =>
+  comments.reduce((total, comment) => total + 1 + countThreadComments(getComments(comment.replies)), 0)
+
 const toLabel = (raw: string) => raw.trim().replace(/^#/, "")
 
 const addUniqueLabel = (existing: string[], raw: string) => {
@@ -101,6 +163,8 @@ export default function TaskDetailPage() {
   const [newComment, setNewComment] = useState("")
   const [editedTaskLabelInput, setEditedTaskLabelInput] = useState("")
   const [isSaving, setIsSaving] = useState(false)
+  const [replyDrafts, setReplyDrafts] = useState<Record<string, string>>({})
+  const [openReplyEditors, setOpenReplyEditors] = useState<Record<string, boolean>>({})
 
   useEffect(() => {
     syncFromServer()
@@ -111,6 +175,7 @@ export default function TaskDetailPage() {
       setEditedTask({
         ...selectedTask,
         tags: getTags(selectedTask),
+        comments: getComments(selectedTask.comments),
         attachments: getAttachments(selectedTask),
       })
       setEditedTaskLabelInput("")
@@ -119,6 +184,7 @@ export default function TaskDetailPage() {
 
   const editedTaskTags = editedTask ? getTags(editedTask) : []
   const editedTaskAttachments = editedTask ? getAttachments(editedTask) : []
+  const commentCount = editedTask ? countThreadComments(getComments(editedTask.comments)) : 0
 
   const allLabels = useMemo(() => {
     const labels = new Map<string, number>()
@@ -166,23 +232,41 @@ export default function TaskDetailPage() {
 
     setEditedTask({
       ...editedTask,
-      comments: [
-        ...(editedTask.comments || []),
-        {
-          id: `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
-          text: newComment.trim(),
-          createdAt: new Date().toISOString(),
-          author: "user",
-        },
-      ],
+      comments: [...getComments(editedTask.comments), buildComment(newComment.trim(), "user")],
     })
     setNewComment("")
   }
 
+  const handleAddReply = (parentId: string) => {
+    if (!editedTask) return
+    const text = replyDrafts[parentId]?.trim()
+    if (!text) return
+
+    setEditedTask({
+      ...editedTask,
+      comments: addReplyToThread(getComments(editedTask.comments), parentId, buildComment(text, "user")),
+    })
+
+    setReplyDrafts((prev) => ({ ...prev, [parentId]: "" }))
+    setOpenReplyEditors((prev) => ({ ...prev, [parentId]: false }))
+  }
+
+  const handleDeleteComment = (commentId: string) => {
+    if (!editedTask) return
+
+    setEditedTask({
+      ...editedTask,
+      comments: removeCommentFromThread(getComments(editedTask.comments), commentId),
+    })
+  }
+
   const handleSave = () => {
     if (!editedTask) return
     setIsSaving(true)
-    updateTask(editedTask.id, editedTask)
+    updateTask(editedTask.id, {
+      ...editedTask,
+      comments: getComments(editedTask.comments),
+    })
     setIsSaving(false)
   }
 
@@ -193,6 +277,70 @@ export default function TaskDetailPage() {
     router.push("/")
   }
 
+  const renderThread = (comments: TaskComment[], depth = 0): JSX.Element[] =>
+    comments.map((comment) => {
+      const replies = getComments(comment.replies)
+      const isReplying = !!openReplyEditors[comment.id]
+      const replyDraft = replyDrafts[comment.id] || ""
+
+      return (
+        <div key={comment.id} className="space-y-2" style={{ marginLeft: depth * 20 }}>
+          <div className={`p-3 rounded-lg border ${comment.author === "assistant" ? "bg-blue-900/20 border-blue-900/40" : "bg-slate-800/60 border-slate-800"}`}>
+            <div className="flex items-center justify-between gap-2 mb-1">
+              <div className="flex items-center gap-2">
+                <span className={`w-7 h-7 rounded-full flex items-center justify-center text-[11px] font-medium ${comment.author === "assistant" ? "bg-blue-600 text-white" : "bg-slate-700 text-slate-200"}`}>
+                  {comment.author === "assistant" ? "AI" : "You"}
+                </span>
+                <span className="text-sm text-slate-300 font-medium">{comment.author === "assistant" ? "Assistant" : "You"}</span>
+                <span className="text-xs text-slate-500">{new Date(comment.createdAt).toLocaleString()}</span>
+              </div>
+              <div className="flex items-center gap-2">
+                <button
+                  type="button"
+                  onClick={() => setOpenReplyEditors((prev) => ({ ...prev, [comment.id]: !prev[comment.id] }))}
+                  className="text-xs text-blue-300 hover:text-blue-200"
+                >
+                  Reply
+                </button>
+                <button
+                  type="button"
+                  onClick={() => handleDeleteComment(comment.id)}
+                  className="text-slate-600 hover:text-red-400"
+                  title="Delete comment"
+                >
+                  <X className="w-3 h-3" />
+                </button>
+              </div>
+            </div>
+            <p className="text-sm text-slate-200 whitespace-pre-wrap">{comment.text}</p>
+          </div>
+
+          {isReplying && (
+            <div className="flex gap-2" style={{ marginLeft: 20 }}>
+              <Textarea
+                value={replyDraft}
+                onChange={(event) => setReplyDrafts((prev) => ({ ...prev, [comment.id]: event.target.value }))}
+                placeholder="Write a reply..."
+                className="flex-1 bg-slate-800 border-slate-700 text-white placeholder-slate-500"
+                rows={2}
+                onKeyDown={(event) => {
+                  if (event.key === "Enter" && event.metaKey) {
+                    handleAddReply(comment.id)
+                  }
+                }}
+              />
+              <div className="flex flex-col gap-2 justify-end">
+                <Button onClick={() => handleAddReply(comment.id)} size="sm">Reply</Button>
+                <Button onClick={() => setOpenReplyEditors((prev) => ({ ...prev, [comment.id]: false }))} variant="ghost" size="sm">Cancel</Button>
+              </div>
+            </div>
+          )}
+
+          {replies.length > 0 && <div className="space-y-2">{renderThread(replies, depth + 1)}</div>}
+        </div>
+      )
+    })
+
   if (!taskId) {
     return (
       <div className="min-h-screen bg-slate-950 text-slate-100 p-6">
@@ -451,55 +599,14 @@ export default function TaskDetailPage() {
             <div className="border-t border-slate-800 pt-6">
               <h4 className="font-medium text-white mb-4 flex items-center gap-2">
                 <MessageSquare className="w-4 h-4" />
-                Notes & Comments ({editedTask.comments?.length || 0})
+                Comments ({commentCount})
               </h4>
 
-              <div className="space-y-4 mb-4">
-                {!editedTask.comments || editedTask.comments.length === 0 ? (
-                  <p className="text-slate-500 text-sm">No notes yet. Add the first one!</p>
+              <div className="space-y-3 mb-4">
+                {commentCount === 0 ? (
+                  <p className="text-slate-500 text-sm">No comments yet. Add the first one.</p>
                 ) : (
-                  editedTask.comments.map((comment) => (
-                    <div
-                      key={comment.id}
-                      className={`flex gap-3 p-3 rounded-lg ${
-                        comment.author === "assistant" ? "bg-blue-900/20" : "bg-slate-800/50"
-                      }`}
-                    >
-                      <div
-                        className={`w-8 h-8 rounded-full flex items-center justify-center text-xs font-medium ${
-                          comment.author === "assistant"
-                            ? "bg-blue-600 text-white"
-                            : "bg-slate-700 text-slate-300"
-                        }`}
-                      >
-                        {comment.author === "assistant" ? "AI" : "You"}
-                      </div>
-                      <div className="flex-1 min-w-0">
-                        <div className="flex items-center justify-between mb-1">
-                          <span className="text-sm font-medium text-slate-300">
-                            {comment.author === "assistant" ? "Assistant" : "You"}
-                          </span>
-                          <div className="flex items-center gap-2">
-                            <span className="text-xs text-slate-500">
-                              {new Date(comment.createdAt).toLocaleString()}
-                            </span>
-                            <button
-                              onClick={() =>
-                                setEditedTask({
-                                  ...editedTask,
-                                  comments: editedTask.comments.filter((entry) => entry.id !== comment.id),
-                                })
-                              }
-                              className="text-slate-600 hover:text-red-400"
-                            >
-                              <X className="w-3 h-3" />
-                            </button>
-                          </div>
-                        </div>
-                        <p className="text-slate-300 text-sm whitespace-pre-wrap">{comment.text}</p>
-                      </div>
-                    </div>
-                  ))
+                  renderThread(getComments(editedTask.comments))
                 )}
               </div>
 
@@ -507,7 +614,7 @@ export default function TaskDetailPage() {
                 <Textarea
                   value={newComment}
                   onChange={(event) => setNewComment(event.target.value)}
-                  placeholder="Add a note or comment..."
+                  placeholder="Add a comment..."
                   className="flex-1 bg-slate-800 border-slate-700 text-white placeholder-slate-500"
                   rows={2}
                   onKeyDown={(event) => {
diff --git a/src/lib/server/taskDb.ts b/src/lib/server/taskDb.ts
index ca0e277..804962a 100644
--- a/src/lib/server/taskDb.ts
+++ b/src/lib/server/taskDb.ts
@@ -11,6 +11,14 @@ export interface TaskAttachment {
   uploadedAt: string;
 }
 
+export interface TaskComment {
+  id: string;
+  text: string;
+  createdAt: string;
+  author: "user" | "assistant";
+  replies?: TaskComment[];
+}
+
 export interface Task {
   id: string;
   title: string;
@@ -23,7 +31,7 @@ export interface Task {
   createdAt: string;
   updatedAt: string;
   dueDate?: string;
-  comments: { id: string; text: string; createdAt: string; author: "user" | "assistant" }[];
+  comments: TaskComment[];
   tags: string[];
   attachments: TaskAttachment[];
 }
@@ -105,6 +113,26 @@ function normalizeAttachments(attachments: unknown): TaskAttachment[] {
     .filter((attachment): attachment is TaskAttachment => attachment !== null);
 }
 
+function normalizeComments(comments: unknown): TaskComment[] {
+  if (!Array.isArray(comments)) return [];
+
+  return comments
+    .map((entry) => {
+      if (!entry || typeof entry !== "object") return null;
+      const value = entry as Partial<TaskComment>;
+      if (typeof value.id !== "string" || typeof value.text !== "string") return null;
+
+      return {
+        id: value.id,
+        text: value.text,
+        createdAt: typeof value.createdAt === "string" ? value.createdAt : new Date().toISOString(),
+        author: value.author === "assistant" ? "assistant" : "user",
+        replies: normalizeComments(value.replies),
+      };
+    })
+    .filter((comment): comment is TaskComment => comment !== null);
+}
+
 function normalizeTask(task: Partial<Task>): Task {
   return {
     id: String(task.id ?? Date.now()),
@@ -118,7 +146,7 @@ function normalizeTask(task: Partial<Task>): Task {
     createdAt: task.createdAt || new Date().toISOString(),
     updatedAt: task.updatedAt || new Date().toISOString(),
     dueDate: task.dueDate || undefined,
-    comments: Array.isArray(task.comments) ? task.comments : [],
+    comments: normalizeComments(task.comments),
     tags: Array.isArray(task.tags) ? task.tags.filter((tag): tag is string => typeof tag === "string") : [],
     attachments: normalizeAttachments(task.attachments),
   };
@@ -343,7 +371,7 @@ export function getData(): DataStore {
       createdAt: task.createdAt,
       updatedAt: task.updatedAt,
       dueDate: task.dueDate ?? undefined,
-      comments: safeParseArray(task.comments, []),
+      comments: normalizeComments(safeParseArray(task.comments, [])),
       tags: safeParseArray(task.tags, []),
       attachments: normalizeAttachments(safeParseArray(task.attachments, [])),
     })),
diff --git a/src/stores/useTaskStore.ts b/src/stores/useTaskStore.ts
index e7b72d3..dd9c219 100644
--- a/src/stores/useTaskStore.ts
+++ b/src/stores/useTaskStore.ts
@@ -22,6 +22,7 @@ export interface Comment {
   text: string
   createdAt: string
   author: 'user' | 'assistant'
+  replies?: Comment[]
 }
 
 export interface TaskAttachment {
@@ -385,6 +386,65 @@ const defaultTasks: Task[] = [
   }
 ]
 
+const normalizeComments = (value: unknown): Comment[] => {
+  if (!Array.isArray(value)) return []
+
+  return value
+    .map((entry) => {
+      if (!entry || typeof entry !== 'object') return null
+      const candidate = entry as Partial<Comment>
+      if (typeof candidate.id !== 'string' || typeof candidate.text !== 'string') return null
+
+      const author = candidate.author === 'assistant' ? 'assistant' : 'user'
+      return {
+        id: candidate.id,
+        text: candidate.text,
+        createdAt: typeof candidate.createdAt === 'string' ? candidate.createdAt : new Date().toISOString(),
+        author,
+        replies: normalizeComments(candidate.replies),
+      }
+    })
+    .filter((comment): comment is Comment => comment !== null)
+}
+
+const normalizeAttachments = (value: unknown): TaskAttachment[] => {
+  if (!Array.isArray(value)) return []
+
+  return value
+    .map((entry) => {
+      if (!entry || typeof entry !== 'object') return null
+      const candidate = entry as Partial<TaskAttachment>
+      if (typeof candidate.id !== 'string' || typeof candidate.name !== 'string' || typeof candidate.dataUrl !== 'string') {
+        return null
+      }
+
+      return {
+        id: candidate.id,
+        name: candidate.name,
+        type: typeof candidate.type === 'string' ? candidate.type : 'application/octet-stream',
+        size: typeof candidate.size === 'number' ? candidate.size : 0,
+        dataUrl: candidate.dataUrl,
+        uploadedAt: typeof candidate.uploadedAt === 'string' ? candidate.uploadedAt : new Date().toISOString(),
+      }
+    })
+    .filter((attachment): attachment is TaskAttachment => attachment !== null)
+}
+
+const normalizeTask = (task: Task): Task => ({
+  ...task,
+  comments: normalizeComments(task.comments),
+  tags: Array.isArray(task.tags) ? task.tags.filter((tag): tag is string => typeof tag === 'string' && tag.trim().length > 0) : [],
+  attachments: normalizeAttachments(task.attachments),
+})
+
+const removeCommentFromThread = (comments: Comment[], targetId: string): Comment[] =>
+  comments
+    .filter((comment) => comment.id !== targetId)
+    .map((comment) => ({
+      ...comment,
+      replies: removeCommentFromThread(normalizeComments(comment.replies), targetId),
+    }))
+
 // Helper to sync to server
 async function syncToServer(projects: Project[], tasks: Task[], sprints: Sprint[]) {
   console.log('>>> syncToServer: saving', tasks.length, 'tasks,', projects.length, 'projects,', sprints.length, 'sprints')
@@ -440,7 +500,7 @@ export const useTaskStore = create<TaskStore>()(
             // ALWAYS use server data if API returns successfully
             set({
               projects: data.projects || [],
-              tasks: data.tasks || [],
+              tasks: (data.tasks || []).map((task: Task) => normalizeTask(task)),
               sprints: data.sprints || [],
               lastSynced: Date.now(),
             })
@@ -511,8 +571,8 @@ export const useTaskStore = create<TaskStore>()(
           id: Date.now().toString(),
           createdAt: new Date().toISOString(),
           updatedAt: new Date().toISOString(),
-          comments: [],
-          attachments: task.attachments || [],
+          comments: normalizeComments([]),
+          attachments: normalizeAttachments(task.attachments),
         }
         set((state) => {
           const newTasks = [...state.tasks, newTask]
@@ -525,7 +585,15 @@ export const useTaskStore = create<TaskStore>()(
         console.log('updateTask called:', id, updates)
         set((state) => {
           const newTasks = state.tasks.map((t) =>
-            t.id === id ? { ...t, ...updates, updatedAt: new Date().toISOString() } : t
+            t.id === id
+              ? normalizeTask({
+                  ...t,
+                  ...updates,
+                  comments: updates.comments !== undefined ? normalizeComments(updates.comments) : t.comments,
+                  attachments: updates.attachments !== undefined ? normalizeAttachments(updates.attachments) : t.attachments,
+                  updatedAt: new Date().toISOString(),
+                } as Task)
+              : t
           )
           const updatedTask = newTasks.find(t => t.id === id)
           console.log('updateTask: updated task:', updatedTask)
@@ -598,11 +666,12 @@ export const useTaskStore = create<TaskStore>()(
           text,
           createdAt: new Date().toISOString(),
           author,
+          replies: [],
         }
         set((state) => {
           const newTasks = state.tasks.map((t) =>
             t.id === taskId
-              ? { ...t, comments: [...t.comments, newComment], updatedAt: new Date().toISOString() }
+              ? { ...t, comments: [...normalizeComments(t.comments), newComment], updatedAt: new Date().toISOString() }
               : t
           )
           syncToServer(state.projects, newTasks, state.sprints)
@@ -614,7 +683,7 @@ export const useTaskStore = create<TaskStore>()(
         set((state) => {
           const newTasks = state.tasks.map((t) =>
             t.id === taskId
-              ? { ...t, comments: t.comments.filter((c) => c.id !== commentId) }
+              ? { ...t, comments: removeCommentFromThread(normalizeComments(t.comments), commentId), updatedAt: new Date().toISOString() }
               : t
           )
           syncToServer(state.projects, newTasks, state.sprints)