diff --git a/retry_mechanism/src/retry_mechanism/cli.py b/retry_mechanism/src/retry_mechanism/cli.py
new file mode 100644
index 0000000..039596c
--- /dev/null
+++ b/retry_mechanism/src/retry_mechanism/cli.py
@@ -0,0 +1,54 @@
+import argparse
+import json
+from pathlib import Path
+from typing import Any
+
+from retry_mechanism.core import retry_if_negative_dt
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Retry Mechanism CLI: prüft Δt und führt ggf. einen einmaligen Retry aus."
+    )
+    parser.add_argument(
+        "--input",
+        required=True,
+        type=str,
+        help="Pfad zur Eingabedatei mit Timing-Messwerten im JSON-Format.",
+    )
+    args = parser.parse_args()
+
+    input_path = Path(args.input)
+    if not input_path.exists() or not input_path.is_file():
+        raise FileNotFoundError(f"Eingabedatei nicht gefunden: {input_path}")
+
+    with input_path.open("r", encoding="utf-8") as f:
+        try:
+            data: Any = json.load(f)
+        except json.JSONDecodeError as e:
+            raise ValueError(f"Ungültiges JSON-Format in {input_path}: {e}") from e
+
+    if not isinstance(data, dict) or "dt" not in data:
+        raise ValueError("Eingabedatei muss ein JSON-Objekt mit Feld 'dt' enthalten.")
+
+    dt_value = data["dt"]
+    if not isinstance(dt_value, (float, int)):
+        raise TypeError("'dt' muss eine Zahl sein (float oder int).")
+
+    corrected_dt = float(retry_if_negative_dt(float(dt_value)))
+
+    retry_taken = dt_value < 0.0
+    retry_fixed = corrected_dt >= 0.0
+
+    result = {
+        "retry_taken": retry_taken,
+        "retry_fixed": retry_fixed,
+        "dt": corrected_dt,
+    }
+
+    json.dump(result, fp=None)  # no-op to check syntax
+    print(json.dumps(result, ensure_ascii=False))
+
+
+if __name__ == "__main__":
+    main()
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