diff --git a/test/comments-merge.test.js b/test/comments-merge.test.js
index 9a14cd9..59a3d98 100644
--- a/test/comments-merge.test.js
+++ b/test/comments-merge.test.js
@@ -55,9 +55,9 @@ function routes(overrides = {}, { body = BODY, comments = [101, 102] } = {}) {
       status: 200,
       body: { number: INDEX, ...req.body, html_url: `https://x/${INDEX}` },
     }),
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
       status: 200,
-      body: comments.map((id) => ({ id, body: `留言 ${id}`, user: { login: 'someone' } })),
+      body: comments.map((id) => ({ id, type: 'comment', body: `留言 ${id}`, user: { login: 'someone' } })),
     },
   });
   for (const id of comments) {
diff --git a/test/issue-extract.test.js b/test/issue-extract.test.js
index 2aa0d37..2965012 100644
--- a/test/issue-extract.test.js
+++ b/test/issue-extract.test.js
@@ -75,9 +75,9 @@ function routes(overrides = {}, { body = FULL_BODY, comments = [] } = {}) {
         labels: [{ id: 55, name: 'ready-for-agent' }],
       },
     },
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
       status: 200,
-      body: comments.map((c, i) => ({ id: 100 + i, body: c.body })),
+      body: comments.map((c, i) => ({ id: 100 + i, type: 'comment', body: c.body })),
     },
     ...overrides,
   });
@@ -340,7 +340,7 @@ test('--dry-run 印出將發出的請求，且不碰 Gitea', async (t) => {
     json.data.requests.map((r) => `${r.method} ${r.path}`),
     [
       `GET /repos/${REPO}/issues/${INDEX}`,
-      `GET /repos/${REPO}/issues/${INDEX}/comments`,
+      `GET /repos/${REPO}/issues/${INDEX}/timeline`,
     ],
   );
   assert.match(
@@ -422,17 +422,20 @@ test('巢狀清單一律攤平，不無聲吃掉內容', async (t) => {
   assert.deepEqual(json.data.驗收標準, ['上層項目', '巢狀項目']);
 });
 
-test('留言逐頁讀完，不是只讀第一頁', async (t) => {
-  // 第一頁滿 50 筆就得再翻一頁；第二頁不滿才收手
-  const page1 = Array.from({ length: 50 }, (_, i) => ({ id: 200 + i }));
-  const page2 = Array.from({ length: 20 }, (_, i) => ({ id: 300 + i }));
+test('留言 timeline 逐頁讀完並去除重複事件', async (t) => {
+  // 第一頁滿 50 筆就得再翻一頁；第二頁包含重複事件，仍只算一次
+  const page1 = Array.from({ length: 50 }, (_, i) => ({ id: 200 + i, type: 'comment' }));
+  const page2 = [
+    page1.at(-1),
+    ...Array.from({ length: 20 }, (_, i) => ({ id: 300 + i, type: 'comment' })),
+  ];
   const reactions = {};
   for (const { id } of [...page1, ...page2]) {
     reactions[`GET /api/v1/repos/${REPO}/issues/comments/${id}/reactions`] = { status: 200, body: [] };
   }
 
   const stub = await withStub(t, {
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: (req) => ({
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: (req) => ({
       status: 200,
       body: req.query.page === '1' ? page1 : page2,
     }),
@@ -441,7 +444,21 @@ test('留言逐頁讀完，不是只讀第一頁', async (t) => {
 
   const { json } = await run([], stub);
 
-  const commentPages = stub.requests.filter((r) => r.path.endsWith(`/issues/${INDEX}/comments`));
-  assert.deepEqual(commentPages.map((r) => r.query.page), ['1', '2']);
-  assert.equal(json.data.未處理留言數, 70, '第二頁的留言也要算進來');
+  const timelinePages = stub.requests.filter((r) => r.path.endsWith(`/issues/${INDEX}/timeline`));
+  assert.deepEqual(timelinePages.map((r) => r.query.page), ['1', '2']);
+  assert.equal(json.data.未處理留言數, 70, '重複事件不應重複計入');
+});
+
+test('timeline 讀取失敗時回傳可區分的錯誤', async (t) => {
+  const stub = await withStub(t, {
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
+      status: 502,
+      body: { message: 'upstream unavailable' },
+    },
+  });
+
+  const { json } = await run([], stub);
+
+  assert.equal(json.error.code, 'HTTP_ERROR');
+  assert.match(json.error.message, /502/);
 });
diff --git a/test/pr-comments.test.js b/test/pr-comments.test.js
index 8997312..908b2dc 100644
--- a/test/pr-comments.test.js
+++ b/test/pr-comments.test.js
@@ -33,13 +33,23 @@ function routes(overrides = {}, options = {}) {
       status: 200,
       body: { ...pull, ...(isPull ? { pull_request: { merged: false } } : {}) },
     },
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
       status: 200,
-      body: general.map((c, i) => ({
-        id: 100 + i,
-        body: c.body,
-        user: { login: c.user ?? 'reviewer' },
-      })),
+      body: [
+        ...general.map((c, i) => ({
+          id: 100 + i,
+          type: 'comment',
+          body: c.body,
+          user: { login: c.user ?? 'reviewer' },
+        })),
+        ...reviews.map((r, i) => ({
+          id: 400 + i,
+          type: 'review',
+          review_id: 200 + i,
+          body: r.body ?? '',
+          user: { login: r.user ?? 'reviewer' },
+        })),
+      ],
     },
     [`GET /api/v1/repos/${REPO}/pulls/${INDEX}/reviews`]: {
       status: 200,
@@ -50,17 +60,6 @@ function routes(overrides = {}, options = {}) {
         user: { login: r.user ?? 'reviewer' },
       })),
     },
-    // 總評在 issue comment 表裡也有一份，timeline 給得出它的 id 與 review_id
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
-      status: 200,
-      body: reviews.map((r, i) => ({
-        id: 400 + i,
-        type: 'review',
-        review_id: 200 + i,
-        body: r.body ?? '',
-        user: { login: r.user ?? 'reviewer' },
-      })),
-    },
   });
 
   general.forEach((c, i) => {
@@ -416,7 +415,7 @@ test('--dry-run 印出將發出的請求，且不碰 Gitea', async (t) => {
     json.data.requests.map((r) => `${r.method} ${r.path}`),
     [
       `GET /repos/${REPO}/issues/${INDEX}`,
-      `GET /repos/${REPO}/issues/${INDEX}/comments`,
+      `GET /repos/${REPO}/issues/${INDEX}/timeline`,
     ],
   );
   assert.match(json.data.note, /reaction|review/);
@@ -426,15 +425,20 @@ test('--dry-run 印出將發出的請求，且不碰 Gitea', async (t) => {
 // ── 分頁 ───────────────────────────────────────────────────────────
 
 test('留言逐頁讀完，不是只讀第一頁', async (t) => {
-  const page1 = Array.from({ length: 50 }, (_, i) => ({ id: 500 + i, body: `第 ${i} 則`, user: { login: 'r' } }));
-  const page2 = [{ id: 999, body: '最後一則', user: { login: 'r' } }];
+  const page1 = Array.from({ length: 50 }, (_, i) => ({
+    id: 500 + i,
+    type: 'comment',
+    body: `第 ${i} 則`,
+    user: { login: 'r' },
+  }));
+  const page2 = [{ id: 999, type: 'comment', body: '最後一則', user: { login: 'r' } }];
   const reactions = {};
   for (const c of [...page1, ...page2]) {
     reactions[`GET /api/v1/repos/${REPO}/issues/comments/${c.id}/reactions`] = { status: 200, body: [] };
   }
 
   const stub = await withStub(t, {
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: (req) => ({
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: (req) => ({
       status: 200,
       body: req.query.page === '1' ? page1 : page2,
     }),
diff --git a/test/pr-reply.test.js b/test/pr-reply.test.js
index 98bf675..5a34330 100644
--- a/test/pr-reply.test.js
+++ b/test/pr-reply.test.js
@@ -43,13 +43,12 @@ function routes(overrides = {}) {
     },
     [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
       status: 200,
-      body: [{ id: REVIEW.commentId, type: 'review', review_id: REVIEW.id, body: REVIEW.body }],
+      body: [
+        { id: REVIEW.commentId, type: 'review', review_id: REVIEW.id, body: REVIEW.body },
+        { id: GENERAL.id, type: 'comment', body: GENERAL.body, user: { login: 'r' } },
+      ],
     },
     [`POST /api/v1/repos/${REPO}/issues/comments/${REVIEW.commentId}/reactions`]: { status: 201, body: {} },
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
-      status: 200,
-      body: [{ id: GENERAL.id, body: GENERAL.body, user: { login: 'r' } }],
-    },
     [`POST /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: { status: 201, body: { id: 900 } },
     [`POST /api/v1/repos/${REPO}/issues/comments/${GENERAL.id}/reactions`]: { status: 201, body: {} },
     [`POST /api/v1/repos/${REPO}/pulls/${INDEX}/reviews`]: { status: 200, body: { id: 901 } },
diff --git a/test/pr-watch.test.js b/test/pr-watch.test.js
index dfa9af3..e4edb72 100644
--- a/test/pr-watch.test.js
+++ b/test/pr-watch.test.js
@@ -44,12 +44,16 @@ function routes({ state = 'open', merged = false, draft = false, general = [], h
         head: head ?? { ref: BRANCH, label: BRANCH },
       },
     },
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
+    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: {
       status: 200,
-      body: general.map((c, i) => ({ id: 100 + i, body: c.body, user: { login: 'reviewer' } })),
+      body: general.map((c, i) => ({
+        id: 100 + i,
+        type: 'comment',
+        body: c.body,
+        user: { login: 'reviewer' },
+      })),
     },
     [`GET /api/v1/repos/${REPO}/pulls/${INDEX}/reviews`]: { status: 200, body: [] },
-    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: { status: 200, body: [] },
   });
   general.forEach((c, i) => {
     base[`GET /api/v1/repos/${REPO}/issues/comments/${100 + i}/reactions`] = {