diff --git a/app/api/v1/coupon.py b/app/api/v1/coupon.py
index 4de69eb..9051f92 100644
--- a/app/api/v1/coupon.py
+++ b/app/api/v1/coupon.py
@@ -183,7 +183,15 @@ def coupon_prompt_should_show(
     device_id: str, db: DbSession
 ) -> CouponPromptShouldShowOut:
     """今天这台设备已 engage(领或拒)过 → should_show=false。客户端据此决定弹不弹
-    (前台 SP 缓存做快速路径,这里是权威)。"""
+    (纯后台判据,客户端不再做前台 SP 缓存判断)。"""
     return CouponPromptShouldShowOut(
         should_show=not coupon_repo.has_engaged_today(db, device_id)
     )
+
+
+@router.post("/prompt/reset", summary="重置今日领券引导窗 engagement(开发测频控用)")
+def coupon_prompt_reset(payload: CouponPromptDismissIn, db: DbSession) -> dict[str, bool]:
+    """删这台设备今天的 engagement → has_engaged_today 变 false,今天又能弹。
+    开发设置「重置今日领券弹窗状态」按钮调。MVP 不鉴权,按 device_id。"""
+    coupon_repo.reset_today_engagement(db, payload.device_id)
+    return {"ok": True}
diff --git a/app/repositories/coupon_state.py b/app/repositories/coupon_state.py
index d36be0a..e255e9f 100644
--- a/app/repositories/coupon_state.py
+++ b/app/repositories/coupon_state.py
@@ -9,7 +9,7 @@ import logging
 from datetime import date, datetime
 from zoneinfo import ZoneInfo
 
-from sqlalchemy import select
+from sqlalchemy import delete, select
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import Session
 
@@ -65,6 +65,19 @@ def mark_engagement(
         db.rollback()
 
 
+def reset_today_engagement(db: Session, device_id: str) -> int:
+    """删这台设备今天的 engagement(开发设置「重置今日领券弹窗状态」调,测频控用)。
+    删后 has_engaged_today → false,今天又能弹。返回删除行数。"""
+    result = db.execute(
+        delete(CouponPromptEngagement).where(
+            CouponPromptEngagement.device_id == device_id,
+            CouponPromptEngagement.engage_date == today_cn(),
+        )
+    )
+    db.commit()
+    return result.rowcount or 0
+
+
 # ===== 领券记录(coupon_claim_record)=====
 
 def record_claims(