diff --git a/routes/reslevis.py b/routes/reslevis.py
index bc7e2cb..07deaed 100644
--- a/routes/reslevis.py
+++ b/routes/reslevis.py
@@ -37,9 +37,10 @@ async def sync_core_get(request: Request) -> None:
     if request.method != "GET":
         return
 
-    repo = CORE_GET_REPO_BY_PATH.get(request.url.path)
-    if repo is None:
+    sync = CORE_GET_SYNC.get(request.url.path)
+    if sync is None:
         return
+    repo, normalizer = sync
 
     try:
         async with httpx.AsyncClient(timeout=CORE_TIMEOUT) as client:
@@ -51,6 +52,8 @@ async def sync_core_get(request: Request) -> None:
         if 200 <= resp.status_code < 300:
             data = resp.json()
             if isinstance(data, list):
+                if normalizer:
+                    data = [normalizer(r) for r in data if isinstance(r, dict)]
                 repo._write_all(data)  # aggiorna i file locali
     except (httpx.RequestError, ValueError):
         # CORE giù o risposta non valida -> uso il file locale
@@ -70,12 +73,77 @@ alarm_repo = AlarmJsonRepository()
 track_repo = TrackJsonRepository()
 tracker_zone_repo = TrackerZoneJsonRepository()
 
-CORE_GET_REPO_BY_PATH = {
-    "/reslevis/getGateways": gateway_repo,
-    "/reslevis/getZones": zone_repo,
-    "/reslevis/getTrackers": tracker_repo,
-    "/reslevis/getTrackerZones": tracker_zone_repo,
-    "/reslevis/getTracks": track_repo,
+def _none_if_empty(v):
+    return None if v in ("", None, 0, "0") else v
+
+def _str_or_none(v):
+    if v in ("", None):
+        return None
+    if isinstance(v, (int, float, bool)):
+        return str(v)
+    return v
+
+def _uuid_list(values):
+    if values in ("", None):
+        return []
+    if isinstance(values, str):
+        values = [v for v in values.split(",") if v]
+    if isinstance(values, (list, tuple, set)):
+        cleaned = []
+        for v in values:
+            if isinstance(v, dict):
+                v = v.get("id") or v.get("uuid")
+            if v in ("", None, 0, "0"):
+                continue
+            cleaned.append(v)
+        return cleaned
+    return [values] if values not in ("", None, 0, "0") else []
+
+def _normalize_gateway(row: dict) -> dict:
+    row = dict(row)
+    row["floor"] = _none_if_empty(row.get("floor"))
+    row["building"] = _none_if_empty(row.get("building"))
+    return row
+
+def _normalize_tracker(row: dict) -> dict:
+    row = dict(row)
+    row["floor"] = _none_if_empty(row.get("floor"))
+    row["building"] = _none_if_empty(row.get("building"))
+    row["battery"] = _str_or_none(row.get("battery"))
+    row["temperature"] = _str_or_none(row.get("temperature"))
+    row["acceleration"] = _str_or_none(row.get("acceleration"))
+    row["heartRate"] = _str_or_none(row.get("heartRate"))
+    return row
+
+def _normalize_track(row: dict) -> dict:
+    row = dict(row)
+    row["gateway"] = _none_if_empty(row.get("gateway"))
+    row["tracker"] = _none_if_empty(row.get("tracker"))
+    row["subject"] = _none_if_empty(row.get("subject"))
+    row["floor"] = _none_if_empty(row.get("floor"))
+    row["building"] = _none_if_empty(row.get("building"))
+    row["timestamp"] = _str_or_none(row.get("timestamp"))
+    row["type"] = _str_or_none(row.get("type"))
+    row["status"] = _str_or_none(row.get("status"))
+    row["gatewayMac"] = _str_or_none(row.get("gatewayMac"))
+    row["trackerMac"] = _str_or_none(row.get("trackerMac"))
+    row["subjectName"] = _str_or_none(row.get("subjectName"))
+    # signal resta float o None
+    row["signal"] = None if row.get("signal") in ("", None) else row.get("signal")
+    return row
+
+def _normalize_zone(row: dict) -> dict:
+    row = dict(row)
+    row["floor"] = _none_if_empty(row.get("floor"))
+    row["building"] = _none_if_empty(row.get("building"))
+    row["groups"] = _uuid_list(row.get("groups"))
+    return row
+
+CORE_GET_SYNC = {
+    "/reslevis/getGateways": (gateway_repo, _normalize_gateway),
+    "/reslevis/getZones": (zone_repo, _normalize_zone),
+    "/reslevis/getTrackers": (tracker_repo, _normalize_tracker),
+    "/reslevis/getTracks": (track_repo, _normalize_track),
 }
 
 
@@ -327,4 +395,4 @@ def updateSubject(item: SubjectItem):
 @router.delete("/removeSubject/{subject_id}", tags=["Reslevis"], dependencies=[Depends(get_current_user)])
 def removeSubject(subject_id: str):
     subject_repo.remove(subject_id)
-    return {"message": "OK"}
\ No newline at end of file
+    return {"message": "OK"}