diff --git a/src/blackboard/db.py b/src/blackboard/db.py
index e1b9ab3..774c5d5 100644
--- a/src/blackboard/db.py
+++ b/src/blackboard/db.py
@@ -415,4 +415,21 @@ _SCHEMA_STATEMENTS = [
     "CREATE INDEX IF NOT EXISTS idx_routing_task ON routing_decisions(task_id)",
     "CREATE INDEX IF NOT EXISTS idx_routing_mode ON routing_decisions(mode)",
     "CREATE INDEX IF NOT EXISTS idx_routing_time ON routing_decisions(created_at)",
+
+    # checkpoints（M3）
+    """CREATE TABLE IF NOT EXISTS checkpoints (
+        id TEXT PRIMARY KEY,
+        task_id TEXT NOT NULL REFERENCES tasks(id),
+        type TEXT NOT NULL CHECK (type IN ('verify', 'decision', 'action')),
+        title TEXT NOT NULL,
+        description TEXT,
+        status TEXT NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'approved', 'rejected')),
+        payload TEXT NOT NULL,
+        created_at TEXT NOT NULL DEFAULT (datetime('now')),
+        resolved_at TEXT,
+        resolved_by TEXT,
+        resolve_note TEXT
+    )""",
+    "CREATE INDEX IF NOT EXISTS idx_checkpoints_task ON checkpoints(task_id)",
+    "CREATE INDEX IF NOT EXISTS idx_checkpoints_status ON checkpoints(status)",
 ]