diff --git a/prediction/models/result.py b/prediction/models/result.py
index bb7a69c..ae439e7 100644
--- a/prediction/models/result.py
+++ b/prediction/models/result.py
@@ -70,8 +70,24 @@ class AnalysisResult:
             """numpy int → Python int 변환."""
             return int(v) if v is not None else 0
 
-        # features dict 내부 numpy 값도 변환
-        safe_features = {k: float(v) for k, v in self.features.items()} if self.features else {}
+        # features dict 내부 numpy 값도 변환 (재귀적 처리)
+        # int/float/bool/str/None/list/dict 모두 허용 (JSON 호환 타입만 유지)
+        def _sanitize(v):
+            if v is None or isinstance(v, (str, bool)):
+                return v
+            if isinstance(v, (int, float)):
+                return float(v) if isinstance(v, float) else int(v)
+            if isinstance(v, dict):
+                return {str(k): _sanitize(val) for k, val in v.items()}
+            if isinstance(v, (list, tuple)):
+                return [_sanitize(x) for x in v]
+            # numpy 스칼라 등은 float 변환 시도, 실패 시 str
+            try:
+                return float(v)
+            except (TypeError, ValueError):
+                return str(v)
+
+        safe_features = _sanitize(self.features) if self.features else {}
 
         return (
             str(self.mmsi),