diff --git a/src/blackboard/operations.py b/src/blackboard/operations.py
index 7e29054..671359b 100644
--- a/src/blackboard/operations.py
+++ b/src/blackboard/operations.py
@@ -616,3 +616,69 @@ class Blackboard:
         finally:
             conn.close()
 
+    # ===================================================================
+    # Archive (v2.8)
+    # ===================================================================
+
+    def archive_task(self, task_id: str) -> bool:
+        """归档单个任务"""
+        conn = self._conn()
+        try:
+            conn.execute("BEGIN IMMEDIATE")
+            conn.execute(
+                "UPDATE tasks SET archived=1, archived_at=datetime('now'), "
+                "updated_at=datetime('now') WHERE id=?",
+                (task_id,),
+            )
+            conn.execute(
+                "INSERT INTO events (task_id, agent, event_type, detail) VALUES (?,?,?,?)",
+                (task_id, "daemon", "task_archived",
+                 json.dumps({"action": "archive"})),
+            )
+            conn.commit()
+            return True
+        finally:
+            conn.close()
+
+    def unarchive_task(self, task_id: str) -> bool:
+        """取消归档"""
+        conn = self._conn()
+        try:
+            conn.execute("BEGIN IMMEDIATE")
+            conn.execute(
+                "UPDATE tasks SET archived=0, archived_at=NULL, "
+                "updated_at=datetime('now') WHERE id=?",
+                (task_id,),
+            )
+            conn.execute(
+                "INSERT INTO events (task_id, agent, event_type, detail) VALUES (?,?,?,?)",
+                (task_id, "daemon", "task_unarchived",
+                 json.dumps({"action": "unarchive"})),
+            )
+            conn.commit()
+            return True
+        finally:
+            conn.close()
+
+    def archive_done_tasks(self) -> int:
+        """一键归档所有 done 状态的任务"""
+        conn = self._conn()
+        try:
+            conn.execute("BEGIN IMMEDIATE")
+            cursor = conn.execute(
+                "UPDATE tasks SET archived=1, archived_at=datetime('now'), "
+                "updated_at=datetime('now') "
+                "WHERE status='done' AND archived=0"
+            )
+            count = cursor.rowcount
+            if count > 0:
+                conn.execute(
+                    "INSERT INTO events (task_id, agent, event_type, detail) VALUES (?,?,?,?)",
+                    (None, "daemon", "task_archived",
+                     json.dumps({"action": "archive_done_batch", "count": count})),
+                )
+            conn.commit()
+            return count
+        finally:
+            conn.close()
+