diff --git a/pokemon_radar_api.py b/pokemon_radar_api.py
index 2b3a9b1..bbd55a0 100644
--- a/pokemon_radar_api.py
+++ b/pokemon_radar_api.py
@@ -102,6 +102,7 @@ class ScanResponse(BaseModel):
     ttl: int
     count_raw: int
     count_filtered: int
+    generated_at: Optional[str] = None  # fetcher 寫入 Redis 的時間（ISO8601 +08:00）
     items: List[Item]
     debug: Dict[str, Any]
 
@@ -211,6 +212,7 @@ def scan(req: ScanRequest) -> Any:
         "ttl": ttl,
         "count_raw": len(items_raw),
         "count_filtered": len(items_filtered),
+        "generated_at": data.get("generated_at"),
         "items": items_filtered,
         "debug": debug_info
     }