diff --git a/infra/agent.py b/infra/agent.py
index 3611a2f..7d1c132 100644
--- a/infra/agent.py
+++ b/infra/agent.py
@@ -18,6 +18,7 @@ import os
 import tempfile
 from datetime import datetime, timezone
 from pathlib import Path
+from zoneinfo import ZoneInfo
 
 import httpx
 from dotenv import load_dotenv
@@ -201,13 +202,25 @@ async def check_disk_rules() -> dict[str, str]:
 
 async def check_health_rules() -> dict[str, str]:
     issues: dict[str, str] = {}
+    # KST 0~7시는 Document Server tier_backfill 가동 시간대 (정책 0~6시 + 잔여 처리 1h buffer).
+    # 26B 가 batch 점유로 /v1/models 응답이 5~10초 lock 되는 게 정상이므로 mlx 알람만 격하.
+    # 정책: ~/Documents/code/hyungi_Document_Server/app/workers/tier_backfill.py NIGHT_START/END_HOUR
+    kst_hour = datetime.now(tz=ZoneInfo("Asia/Seoul")).hour
+    is_backfill_window = 0 <= kst_hour < 7
+
     for svc in HEALTH_SERVICES:
         result = await service_health(svc)
         if not result.ok:
+            if svc == "mlx" and is_backfill_window:
+                log.info("[mute] mlx down — KST %d시 backfill window", kst_hour)
+                continue
             detail = result.error or result.status
             k = _health_key(svc, "down")
             issues[k] = f"서비스 다운: {svc} — {detail}"
         elif result.status == "degraded":
+            if svc == "mlx" and is_backfill_window:
+                log.info("[mute] mlx degraded — KST %d시 backfill window", kst_hour)
+                continue
             k = _health_key(svc, "degraded")
             issues[k] = f"서비스 저하: {svc}"
     return issues