diff --git a/cloud/tests/test_worker.py b/cloud/tests/test_worker.py
index c9c7f80..4293781 100644
--- a/cloud/tests/test_worker.py
+++ b/cloud/tests/test_worker.py
@@ -481,6 +481,31 @@ class WorkerTestCase(unittest.TestCase):
         self.assertEqual(result["status"], "interrupted")
         self.assertEqual(_status(self.db_path, "A"), "interrupted")
 
+    def test_final_audit_detail_carries_error(self):
+        # 2026-10-29 任务 A 教训：终态审计只记 task_id 时，
+        # interrupted/failed 的原因事后无法区分，且自动续跑
+        # 会把 error_text 覆盖掉。非完成终态的审计 detail
+        # 必须带上 error，完成态仍只记 task_id。
+        _insert_task(self.db_path, "A")
+
+        def failing(cmd):
+            return SimpleNamespace(returncode=1, stdout="",
+                                   stderr="dispatch boom xyz")
+
+        worker = self._worker(runner=failing)
+        result = worker.run_one()
+        self.assertEqual(result["status"], "failed")
+        from cloud.auth import AuthStore
+        store = AuthStore(self.db_path)
+        try:
+            entries = [e for e in store.list_audit("p1")
+                       if e["action"] == "worker_failed"]
+        finally:
+            store.conn.close()
+        self.assertTrue(entries)
+        self.assertTrue(entries[0]["detail"].startswith("A:"))
+        self.assertIn("boom", entries[0]["detail"])
+
     # -- 缺 key 门 --------------------------------------------------------
     def test_missing_key_fails_clearly_and_does_not_run(self):
         _insert_task(self.db_path, "A")
diff --git a/cloud/worker.py b/cloud/worker.py
index a995183..3a6c29c 100644
--- a/cloud/worker.py
+++ b/cloud/worker.py
@@ -5167,12 +5167,22 @@ class Worker:
         if final_written:
             # 审计名须与终态一致：interrupted 任务记 worker_failed
             # 会把“可续跑的中断”误读成失败，误导后续排查。
+            # 终态审计细节（2026-10-29 任务 A 教训）：interrupted /
+            # failed 时只记 task_id，事后完全无法区分是取消、
+            # 配额、host 返回 interrupted 还是其它失败——且自动
+            # 续跑会把 error_text 覆盖掉，第一轮的原因就此丢失。
+            # 因此非完成终态的审计 detail 带上 error（截 500 字、
+            # 去换行，不含 prompt/key），完成态仍只记 task_id。
+            _final_detail = task_id
+            if final in ("interrupted", "failed") and error:
+                _final_detail = "%s: %s" % (
+                    task_id, str(error)[:500].replace("\n", " "))
             self._audit(task["project_id"],
                         "worker_quota_stop" if quota_stop else
                         ("worker_completed" if final == "completed"
                          else "worker_interrupted"
                          if final == "interrupted"
-                         else "worker_failed"), task_id)
+                         else "worker_failed"), _final_detail)
             log_event(self.logger,
                       "worker_quota_stop" if quota_stop else
                       ("worker_completed" if final == "completed"