diff --git a/src/web-dashboard-data.test.ts b/src/web-dashboard-data.test.ts
index 3b3d6f5..2dd008b 100644
--- a/src/web-dashboard-data.test.ts
+++ b/src/web-dashboard-data.test.ts
@@ -442,6 +442,84 @@ describe('web dashboard room activity data', () => {
     ]);
   });
 
+  it('hides legacy delivered work items without discord delivery evidence', () => {
+    const activity = buildWebDashboardRoomActivity({
+      serviceId: 'codex-main',
+      entry: {
+        jid: 'dc:ops',
+        name: '#ops',
+        folder: 'ops',
+        agentType: 'codex',
+        status: 'inactive',
+        elapsedMs: null,
+        pendingMessages: false,
+        pendingTasks: 0,
+      },
+      pairedTask: null,
+      turns: [],
+      attempts: [],
+      outputs: [],
+      outboundItems: [
+        makeDeliveredWorkItem({
+          id: 103,
+          delivery_role: null,
+          delivery_message_id: null,
+          result_payload: '서비스 재시작으로 이전 작업이 중단됐습니다.',
+        }),
+      ],
+      messages: [],
+    });
+
+    expect(activity.messages).toEqual([]);
+  });
+
+  it('keeps legacy delivered work items when a discord echo exists', () => {
+    const activity = buildWebDashboardRoomActivity({
+      serviceId: 'codex-main',
+      entry: {
+        jid: 'dc:ops',
+        name: '#ops',
+        folder: 'ops',
+        agentType: 'codex',
+        status: 'inactive',
+        elapsedMs: null,
+        pendingMessages: false,
+        pendingTasks: 0,
+      },
+      pairedTask: null,
+      turns: [],
+      attempts: [],
+      outputs: [],
+      outboundItems: [
+        makeDeliveredWorkItem({
+          id: 104,
+          delivery_message_id: null,
+          result_payload: 'TASK_DONE\n\nlegacy delivered output',
+        }),
+      ],
+      messages: [
+        {
+          id: 'discord-legacy-echo',
+          chat_jid: 'dc:ops',
+          sender: 'bot-owner',
+          sender_name: '오너',
+          content: 'TASK_DONE\n\nlegacy delivered output',
+          timestamp: '2026-04-26T05:30:11.000Z',
+          is_from_me: true,
+          is_bot_message: true,
+          message_source_kind: 'bot',
+        },
+      ],
+    });
+
+    expect(activity.messages).toEqual([
+      expect.objectContaining({
+        id: 'work:104',
+        content: 'TASK_DONE\n\nlegacy delivered output',
+      }),
+    ]);
+  });
+
   it('merges canonical outbound and recent messages in chronological order', () => {
     const activity = buildWebDashboardRoomActivity({
       serviceId: 'codex-main',
diff --git a/src/web-dashboard-data.ts b/src/web-dashboard-data.ts
index 5d0785e..aaf1b44 100644
--- a/src/web-dashboard-data.ts
+++ b/src/web-dashboard-data.ts
@@ -575,6 +575,15 @@ function isDuplicateOfCanonicalOutbound(
   });
 }
 
+function hasDiscordEchoForCanonicalOutbound(
+  canonical: WebDashboardRoomMessage,
+  messages: WebDashboardRoomMessage[],
+): boolean {
+  return messages.some((message) =>
+    isDuplicateOfCanonicalOutbound(message, [canonical]),
+  );
+}
+
 function compareRoomMessagesByTimestamp(
   a: WebDashboardRoomMessage,
   b: WebDashboardRoomMessage,
@@ -670,19 +679,36 @@ export function buildWebDashboardRoomActivity(args: {
     ? (latestAttemptByTurnId.get(currentTurn.turn_id) ?? null)
     : null;
   const outputLimit = args.outputLimit ?? 4;
-  const canonicalOutboundMessages = (args.outboundItems ?? [])
-    .map(sanitizeCanonicalOutboundMessage)
+  const sanitizedRecentMessages = args.messages
+    .filter((message) => !isTaskStatusMessage(message))
+    .map(sanitizeRoomMessage)
     .filter((message): message is WebDashboardRoomMessage => Boolean(message));
+  const canonicalOutboundMessages = (args.outboundItems ?? [])
+    .map((item) => ({
+      item,
+      message: sanitizeCanonicalOutboundMessage(item),
+    }))
+    .filter(
+      (
+        candidate,
+      ): candidate is {
+        item: WorkItem;
+        message: WebDashboardRoomMessage;
+      } => Boolean(candidate.message),
+    )
+    .filter(
+      ({ item, message }) =>
+        Boolean(item.delivery_message_id) ||
+        hasDiscordEchoForCanonicalOutbound(message, sanitizedRecentMessages),
+    )
+    .map(({ message }) => message);
   const canonicalDeliveryMessageIds = new Set(
     (args.outboundItems ?? [])
       .map((item) => item.delivery_message_id)
       .filter((id): id is string => Boolean(id)),
   );
-  const recentMessages = args.messages
+  const recentMessages = sanitizedRecentMessages
     .filter((message) => !canonicalDeliveryMessageIds.has(message.id))
-    .filter((message) => !isTaskStatusMessage(message))
-    .map(sanitizeRoomMessage)
-    .filter((message): message is WebDashboardRoomMessage => Boolean(message))
     .filter(
       (message) =>
         !isDuplicateOfCanonicalOutbound(message, canonicalOutboundMessages),