diff --git a/gps_sync/src/gps_sync/cli.py b/gps_sync/src/gps_sync/cli.py
new file mode 100644
index 0000000..e0bac85
--- /dev/null
+++ b/gps_sync/src/gps_sync/cli.py
@@ -0,0 +1,58 @@
+import argparse
+import json
+from pathlib import Path
+from typing import Any
+
+import pandas as pd  # required per dependencies
+
+from gps_sync.core import sync_with_gps
+
+
+def _load_json(path: Path) -> list[dict[str, Any]]:
+    with path.open('r', encoding='utf-8') as f:
+        data = json.load(f)
+    if not isinstance(data, list):
+        raise ValueError(f"Expected list of dict for JSON file: {path}")
+    return data
+
+
+def _write_json(data: list[dict[str, Any]], path: Path) -> None:
+    with path.open('w', encoding='utf-8') as f:
+        json.dump(data, f, ensure_ascii=False, indent=2)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Synchronisiert WLAN-Messdaten mit GPS-Positionsdaten anhand von Zeitstempeln."
+    )
+    parser.add_argument('--gps', required=True, help='Pfad zur GPS-JSON-Datei')
+    parser.add_argument('--wifi', required=True, help='Pfad zur WLAN-JSON-Datei')
+    parser.add_argument('--out', required=True, help='Pfad zur Ausgabe-JSON-Datei mit synchronisierten Daten')
+
+    args = parser.parse_args()
+
+    gps_path = Path(args.gps)
+    wifi_path = Path(args.wifi)
+    out_path = Path(args.out)
+
+    assert gps_path.exists(), f"GPS-Datei nicht gefunden: {gps_path}"
+    assert wifi_path.exists(), f"WLAN-Datei nicht gefunden: {wifi_path}"
+
+    gps_data = _load_json(gps_path)
+    wifi_data = _load_json(wifi_path)
+
+    synced_data = sync_with_gps(gps_data, wifi_data)
+
+    if not isinstance(synced_data, list):
+        raise TypeError("sync_with_gps muss eine Liste von Dictionaries zurückgeben.")
+
+    # Validate fields based on data model SyncedDataEntry
+    for entry in synced_data:
+        if not all(k in entry for k in ("timestamp", "latitude", "longitude", "signal_strength")):
+            raise ValueError("Ungültiger Dateneintrag im synchronisierten Ergebnis.")
+
+    _write_json(synced_data, out_path)
+
+
+if __name__ == '__main__':
+    main()