diff --git a/apps/web/src/lib/useOrgChat.ts b/apps/web/src/lib/useOrgChat.ts
index 269946d..10fe92b 100644
--- a/apps/web/src/lib/useOrgChat.ts
+++ b/apps/web/src/lib/useOrgChat.ts
@@ -22,16 +22,33 @@ const messages = shallowRef<ChatMessage[]>([]);
 const activeRoomId = ref('');
 let pingTimer: ReturnType<typeof setInterval> | null = null;
 
-function normalizeIncoming(raw: Record<string, unknown>, roomFallback: string): ChatMessage | null {
+function messageTs(item: ChatMessage): number {
+  const t = new Date(item.createdAt).getTime();
+  return Number.isNaN(t) ? 0 : t;
+}
+
+/** قدیمی → جدید (آخرین پیام پایین لیست) */
+function sortAsc(items: ChatMessage[]): ChatMessage[] {
+  return [...items].sort((a, b) => {
+    const d = messageTs(a) - messageTs(b);
+    if (d !== 0) return d;
+    return a.id.localeCompare(b.id);
+  });
+}
+
+function normalizeIncoming(
+  raw: Record<string, unknown>,
+  roomFallback: string,
+): ChatMessage | null {
   const base =
     raw.message && typeof raw.message === 'object'
       ? (raw.message as Record<string, unknown>)
       : raw;
   const content = String(base.content ?? base.text ?? base.body ?? '').trim();
   if (!content && !base.attachments) return null;
-  const id = String(base.id ?? base.message_id ?? crypto.randomUUID());
+  const id = String(base.id ?? base.message_id ?? '').trim();
   return {
-    id,
+    id: id || `tmp-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
     roomId: String(base.room_id ?? raw.room_id ?? roomFallback),
     senderId: String(
       base.sender_id ?? base.user_id ?? base.from_user_id ?? raw.sender_id ?? '',
@@ -45,6 +62,36 @@ function normalizeIncoming(raw: Record<string, unknown>, roomFallback: string):
   };
 }
 
+/** ادغام: همان id جایگزین می‌شود؛ optimistic مشابه با echo سوکت یکی می‌شود */
+function mergeMessages(incoming: ChatMessage, list: ChatMessage[]): ChatMessage[] {
+  const byId = list.findIndex((m) => m.id === incoming.id);
+  if (byId >= 0) {
+    const next = [...list];
+    next[byId] = { ...list[byId], ...incoming, optimistic: false };
+    return sortAsc(next);
+  }
+
+  // echo سوکت بعد از optimistic با همان متن/فرستنده/اتاق
+  const optimisticIdx = list.findIndex(
+    (m) =>
+      m.optimistic &&
+      m.roomId === incoming.roomId &&
+      m.senderId === incoming.senderId &&
+      m.content === incoming.content,
+  );
+  if (optimisticIdx >= 0) {
+    const next = [...list];
+    next[optimisticIdx] = {
+      ...list[optimisticIdx],
+      ...incoming,
+      optimistic: false,
+    };
+    return sortAsc(next);
+  }
+
+  return sortAsc([...list, incoming]);
+}
+
 async function ensureSession(): Promise<ConversationSessionDto> {
   if (sessionCache) return sessionCache;
   const { data } = await api.get<ConversationSessionDto>('/conversations/session');
@@ -68,6 +115,21 @@ function disconnectSocket() {
   status.value = 'closed';
 }
 
+function onSocketMessage(event: MessageEvent) {
+  const raw = String(event.data ?? '').trim();
+  if (!raw || raw === 'pong' || raw === 'ping') return;
+  try {
+    const parsed = JSON.parse(raw) as Record<string, unknown>;
+    const type = String(parsed.type ?? '').toLowerCase();
+    if (type === 'seen' || type === 'typing' || type === 'read' || type === 'pong') return;
+    const msg = normalizeIncoming(parsed, activeRoomId.value);
+    if (!msg || !activeRoomId.value || msg.roomId !== activeRoomId.value) return;
+    messages.value = mergeMessages(msg, messages.value);
+  } catch {
+    // ignore
+  }
+}
+
 async function connectSocket() {
   const session = await ensureSession();
   if (socket?.readyState === WebSocket.OPEN) return;
@@ -88,19 +150,7 @@ async function connectSocket() {
     clearPing();
   });
 
-  socket.addEventListener('message', (event) => {
-    const raw = String(event.data ?? '').trim();
-    if (!raw || raw === 'pong' || raw === 'ping') return;
-    try {
-      const parsed = JSON.parse(raw) as Record<string, unknown>;
-      if (parsed.type === 'seen' || parsed.type === 'typing' || parsed.type === 'read') return;
-      const msg = normalizeIncoming(parsed, activeRoomId.value);
-      if (!msg || msg.roomId !== activeRoomId.value) return;
-      messages.value = [...messages.value, msg];
-    } catch {
-      // ignore
-    }
-  });
+  socket.addEventListener('message', onSocketMessage);
 
   await new Promise<void>((resolve, reject) => {
     if (!socket) return reject(new Error('socket missing'));
@@ -145,9 +195,10 @@ export function useOrgChat() {
       if (!res.ok) throw new Error('messages failed');
       const body = await res.json();
       const list = Array.isArray(body) ? body : body?.data ?? [];
-      messages.value = list
+      const normalized = list
         .map((item: Record<string, unknown>) => normalizeIncoming(item, roomId))
         .filter(Boolean) as ChatMessage[];
+      messages.value = sortAsc(normalized);
     } finally {
       loadingMessages.value = false;
     }
@@ -177,7 +228,7 @@ export function useOrgChat() {
       reply,
       optimistic: true,
     };
-    messages.value = [...messages.value, optimistic];
+    messages.value = mergeMessages(optimistic, messages.value);
     socket.send(JSON.stringify(payload));
     sendRead(roomId);
   }
diff --git a/apps/web/src/views/ConversationsView.vue b/apps/web/src/views/ConversationsView.vue
index 0d0761c..fe205e3 100644
--- a/apps/web/src/views/ConversationsView.vue
+++ b/apps/web/src/views/ConversationsView.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, onMounted, ref, watch } from 'vue';
+import { computed, nextTick, onMounted, ref, watch } from 'vue';
 import { RouterLink } from 'vue-router';
 import axios from 'axios';
 import { api } from '@/lib/api';
@@ -29,9 +29,17 @@ const groupMemberIds = ref<string[]>([]);
 const dmPeerId = ref('');
 
 const { messages, loadingMessages, status, loadMessages, sendText, sendRead } = useOrgChat();
+const msgStreamEl = ref<HTMLElement | null>(null);
 
 const canCreateGroup = computed(() => access.value?.canCreateGroup ?? false);
 
+async function scrollToBottom() {
+  await nextTick();
+  const el = msgStreamEl.value;
+  if (!el) return;
+  el.scrollTop = el.scrollHeight;
+}
+
 const sortedRooms = computed(() =>
   [...rooms.value].sort((a, b) => {
     const ta = a.lastMessageAt ? new Date(a.lastMessageAt).getTime() : 0;
@@ -154,6 +162,17 @@ watch(activeRoom, () => {
   draft.value = '';
 });
 
+watch(
+  () => messages.value.length,
+  () => {
+    void scrollToBottom();
+  },
+);
+
+watch(loadingMessages, (v) => {
+  if (!v) void scrollToBottom();
+});
+
 onMounted(() => {
   void bootstrap();
 });
@@ -230,7 +249,7 @@ onMounted(() => {
           </div>
 
           <div v-if="loadingMessages" class="muted center pad">در حال دریافت پیام‌ها…</div>
-          <ul v-else class="msg-stream">
+          <ul v-else ref="msgStreamEl" class="msg-stream">
             <li
               v-for="msg in messages"
               :key="msg.id"