diff --git a/REAMME.md b/REAMME.md
index 4a103ed..696f67b 100755
--- a/REAMME.md
+++ b/REAMME.md
@@ -34,6 +34,18 @@ WORKBOOK_ID=your-workbook-id ./update.sh
 - 合并结果末尾增加生成的 `LinkName` 列。
 - 看板对仅包含 `Date`、且 `Commission` 与 `GMV` 均为空的日期行进行过滤；该过滤由 `index.html` 完成。
 
+### 同步运行日志
+
+`data/sync-log.json` 保存最后一次成功同步的摘要，字段包括：
+
+- `last_success_at`：UTC ISO-8601 时间，使用 `Z` 表示 UTC。
+- `last_success_at_shanghai`：`Asia/Shanghai` 时区的 ISO 时间。
+- `worksheet_count`：本次读取的工作表数量。
+- `record_count`：合并结果中的数据记录数量，不含标题行。
+- `artifact_bytes`：本次生成的 `data/merged.html` 字节数。
+
+只有 Google Sheets 读取、合并和 HTML 生成全部成功后才会生成并发布新的运行日志。同步失败或 Git 推送失败不会用失败时间覆盖已发布的最后成功时间。AgentStage 每次成功运行都会提交 `data/merged.html` 或 `data/sync-log.json` 中发生变化的文件；即使数据内容没有变化，运行日志的成功时间也会变化，因此仍可通过 Git 提交和日志确认运行记录。
+
 ## 看板功能
 
 看板页面采用上下布局，包含以下内容：
diff --git a/index.html b/index.html
index ce239b4..4cfcfa9 100755
--- a/index.html
+++ b/index.html
@@ -132,7 +132,6 @@
     </section>
 
     <section class="metrics" id="metrics" aria-label="数据概览" hidden>
-      <div class="metric"><span class="metric-label">数据更新时间</span><strong class="metric-value" id="updated-at">—</strong></div>
       <div class="metric"><span class="metric-label">记录数</span><strong class="metric-value" id="record-count">—</strong></div>
       <div class="metric"><span class="metric-label">LinkName 数</span><strong class="metric-value" id="link-count">—</strong></div>
       <div class="metric"><span class="metric-label">Total Commission</span><strong class="metric-value" id="total-commission">—</strong></div>
@@ -167,6 +166,7 @@
       'use strict';
 
       var DATA_URL = 'data/merged.html';
+      var SYNC_LOG_URL = 'data/sync-log.json';
       var RATES_URL = 'https://open.er-api.com/v6/latest/USD';
       var REQUIRED_FIELDS = ['Date', 'Commission', 'Order', 'GMV', 'Currency', 'LinkName'];
       var charts = [];
@@ -190,7 +190,6 @@
         rangeButtons: Array.from(document.querySelectorAll('[data-range]')),
         rateStatus: document.getElementById('rate-status'),
         metrics: document.getElementById('metrics'),
-        updatedAt: document.getElementById('updated-at'),
         recordCount: document.getElementById('record-count'),
         linkCount: document.getElementById('link-count'),
         totalCommission: document.getElementById('total-commission'),
@@ -205,7 +204,16 @@
         linkCommission: document.getElementById('link-commission-chart'),
         linkGmv: document.getElementById('link-gmv-chart')
       };
-      var state = { rawRecords: [], sourceCurrencies: [], selectedCurrency: '', latestDate: null, dateOnlyRows: 0, invalidCurrencyRows: 0 };
+      var state = {
+        rawRecords: [],
+        sourceCurrencies: [],
+        selectedCurrency: '',
+        latestDate: null,
+        dateOnlyRows: 0,
+        invalidCurrencyRows: 0,
+        syncLog: null,
+        syncLogUnavailable: false
+      };
 
       function setStatus(message, status) {
         elements.status.textContent = message;
@@ -277,6 +285,8 @@
 
       function updateNotice() {
         var messages = [];
+        if (state.syncLog) messages.push('最后成功运行：' + state.syncLog.displayTime);
+        if (state.syncLogUnavailable) messages.push('运行日志暂不可用。');
         if (state.dateOnlyRows) messages.push('已过滤 ' + formatNumber(state.dateOnlyRows) + ' 条只有 Date、Commission 和 GMV 均为空的日期行。');
         if (state.invalidCurrencyRows) messages.push('已排除 ' + formatNumber(state.invalidCurrencyRows) + ' 条币种为空、Unknown 或格式无效且包含金额的记录，请检查原始数据。');
         if (state.sourceCurrencies.length > 1) messages.push('检测到多个已知源币种（' + state.sourceCurrencies.join('、') + '），已统一换算为 USD，不能切换到 IDR。');
@@ -284,6 +294,15 @@
         elements.warning.hidden = messages.length === 0;
       }
 
+      function parseSyncLog(payload) {
+        if (!payload || typeof payload.last_success_at !== 'string' || !payload.last_success_at.trim() || Number.isNaN(Date.parse(payload.last_success_at))) {
+          throw new Error('运行日志缺少有效的 last_success_at。');
+        }
+        var shanghaiTime = typeof payload.last_success_at_shanghai === 'string' ? payload.last_success_at_shanghai.trim() : '';
+        var displayTime = shanghaiTime && !Number.isNaN(Date.parse(shanghaiTime)) ? shanghaiTime : payload.last_success_at;
+        return { displayTime: displayTime };
+      }
+
       function setRateStatus(message) { elements.rateStatus.textContent = message; }
 
       function updateCurrencyOptions() {
@@ -415,8 +434,7 @@
           return total + (record.gmv === null ? 0 : record.gmv);
         }, 0);
         elements.title.textContent = 'TTSHOP 销售看板 · ' + state.selectedCurrency;
-        elements.subtitle.textContent = 'Commission 与 GMV 趋势（当前加载时间：' + dateFormatter.format(new Date()) + '）';
-        elements.updatedAt.textContent = dateFormatter.format(new Date());
+        elements.subtitle.textContent = 'Commission 与 GMV 趋势（数据来自最近一次成功同步）';
         elements.recordCount.textContent = formatNumber(records.length);
         elements.linkCount.textContent = formatNumber(links.size);
         elements.totalCommission.textContent = state.selectedCurrency + ' ' + formatNumber(totalCommission);
@@ -551,11 +569,20 @@
       }
 
       function loadData() {
-        fetch(DATA_URL, { cache: 'no-store' }).then(function (response) {
+        var dataPromise = fetch(DATA_URL, { cache: 'no-store' }).then(function (response) {
           if (!response.ok) throw new Error('无法读取 data/merged.html（HTTP ' + response.status + '）。');
           return response.text();
-        }).then(function (htmlText) {
-          var result = readTable(htmlText);
+        });
+        var syncLogPromise = fetch(SYNC_LOG_URL, { cache: 'no-store' }).then(function (response) {
+          if (!response.ok) throw new Error('无法读取 data/sync-log.json（HTTP ' + response.status + '）。');
+          return response.json();
+        }).then(parseSyncLog).catch(function () {
+          state.syncLogUnavailable = true;
+          return null;
+        });
+        Promise.all([dataPromise, syncLogPromise]).then(function (results) {
+          var result = readTable(results[0]);
+          state.syncLog = results[1];
           state.rawRecords = result.records;
           state.dateOnlyRows = result.dateOnlyRows;
           state.invalidCurrencyRows = result.invalidCurrencyRows;
diff --git a/sync.py b/sync.py
index a498bf2..700086b 100755
--- a/sync.py
+++ b/sync.py
@@ -10,9 +10,11 @@ import subprocess
 import sys
 import tempfile
 import zipfile
+from datetime import datetime, timezone
 from io import BytesIO
 from pathlib import Path
 from urllib.parse import urlencode
+from zoneinfo import ZoneInfo
 import xml.etree.ElementTree as ET
 
 import requests
@@ -21,6 +23,7 @@ import requests
 ROOT = Path(__file__).resolve().parent
 WORKBOOK_ID = os.getenv("WORKBOOK_ID", "1DPbdVsX3SG_kgDXs2j34mDAgplRSfcAWKKG9yqalFmw")
 PUBLISH_PATH = Path("data/merged.html")
+SYNC_LOG_PATH = Path("data/sync-log.json")
 GVIZ_PREFIX = "google.visualization.Query.setResponse("
 
 
@@ -171,18 +174,28 @@ def run_git(args: list[str], env: dict[str, str]) -> subprocess.CompletedProcess
     )
 
 
-def publish(content: bytes) -> None:
-    target = ROOT / PUBLISH_PATH
-    if target.exists() and target.read_bytes() == content:
-        print("data/merged.html is unchanged")
+def publish(content: bytes, sync_log: dict[str, object]) -> None:
+    log_content = (json.dumps(sync_log, ensure_ascii=False, indent=2) + "\n").encode("utf-8")
+    targets = {
+        PUBLISH_PATH: content,
+        SYNC_LOG_PATH: log_content,
+    }
+    changed = False
+    for relative_path, target_content in targets.items():
+        target = ROOT / relative_path
+        if not target.exists() or target.read_bytes() != target_content:
+            changed = True
+        target.parent.mkdir(parents=True, exist_ok=True)
+        target.write_bytes(target_content)
+    if not changed:
+        print("data/merged.html and data/sync-log.json are unchanged")
         return
-    target.parent.mkdir(parents=True, exist_ok=True)
-    target.write_bytes(content)
 
     env = os.environ.copy()
     env["GIT_TERMINAL_PROMPT"] = "0"
     askpass_path: str | None = None
     credential = env.get("GIT_CREDENTIAL_SECRET", "")
+    paths = [str(PUBLISH_PATH), str(SYNC_LOG_PATH)]
     if credential:
         with tempfile.NamedTemporaryFile("w", prefix="ttshop-askpass-", delete=False) as file:
             file.write(
@@ -197,22 +210,23 @@ def publish(content: bytes) -> None:
         env["GIT_ASKPASS"] = askpass_path
 
     try:
-        run_git(["add", "--", str(PUBLISH_PATH)], env)
+        run_git(["add", "--", *paths], env)
         staged = subprocess.run(
-            ["git", "diff", "--cached", "--quiet", "--", str(PUBLISH_PATH)],
+            ["git", "diff", "--cached", "--quiet", "--", *paths],
             cwd=ROOT, env=env, check=False,
         )
         if staged.returncode not in (0, 1):
             raise RuntimeError("could not inspect staged output")
         if staged.returncode == 0:
-            print("data/merged.html is unchanged")
+            print("data/merged.html and data/sync-log.json are unchanged")
             return
         run_git([
             "-c", "user.name=TTSHOP Sync", "-c", "user.email=ttshop-sync@localhost",
-            "commit", "--no-gpg-sign", "-m", "Update merged Google Sheet",
+            "commit", "--only", "--no-gpg-sign", "-m", "Update merged Google Sheet and sync log",
+            "--", *paths,
         ], env)
         run_git(["push", "origin", "HEAD:main"], env)
-        print("published data/merged.html")
+        print("published data/merged.html and data/sync-log.json")
     finally:
         if askpass_path:
             Path(askpass_path).unlink(missing_ok=True)
@@ -222,13 +236,23 @@ def sync() -> None:
     export_url = f"https://docs.google.com/spreadsheets/d/{WORKBOOK_ID}/export?format=xlsx"
     response = requests.get(export_url, timeout=30)
     response.raise_for_status()
+    worksheet_names = sheet_names(response.content)
     sheets = []
-    for name in sheet_names(response.content):
+    for name in worksheet_names:
         headers, rows = normalize_sheet(name, read_gviz(name))
         if headers:
             sheets.append((name, headers, rows))
     headers, rows = merge_sheets(sheets)
-    publish(render_html(headers, rows))
+    content = render_html(headers, rows)
+    success_at = datetime.now(timezone.utc)
+    sync_log = {
+        "last_success_at": success_at.isoformat().replace("+00:00", "Z"),
+        "last_success_at_shanghai": success_at.astimezone(ZoneInfo("Asia/Shanghai")).isoformat(),
+        "worksheet_count": len(worksheet_names),
+        "record_count": len(rows),
+        "artifact_bytes": len(content),
+    }
+    publish(content, sync_log)
 
 
 def notify_failure(error: Exception) -> None: