diff --git a/spike_classifier/src/spike_classifier/cli.py b/spike_classifier/src/spike_classifier/cli.py
new file mode 100644
index 0000000..45449ba
--- /dev/null
+++ b/spike_classifier/src/spike_classifier/cli.py
@@ -0,0 +1,47 @@
+import argparse
+import json
+import os
+from pathlib import Path
+from spike_classifier.core import classify_spikes
+
+
+def main() -> None:
+    """Command-line interface for classifying CPU spike events."""
+    parser = argparse.ArgumentParser(
+        description="Classify CPU spike events based on reorder metrics and CPU transitions."
+    )
+    parser.add_argument(
+        "--input",
+        required=True,
+        help="Path to input JSON file containing spike events."
+    )
+    parser.add_argument(
+        "--output",
+        required=True,
+        help="Path to output JSON file for classified spikes."
+    )
+    args = parser.parse_args()
+
+    input_path = Path(args.input)
+    output_path = Path(args.output)
+
+    if not input_path.exists() or not input_path.is_file():
+        parser.error(f"Input file not found: {input_path}")
+
+    try:
+        with input_path.open('r', encoding='utf-8') as infile:
+            json_data = json.load(infile)
+    except json.JSONDecodeError as e:
+        parser.error(f"Invalid JSON in input file: {e}")
+
+    classified = classify_spikes(json_data)
+
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    with output_path.open('w', encoding='utf-8') as outfile:
+        json.dump(classified, outfile, indent=2, ensure_ascii=False)
+
+    print(f"Classified {len(classified)} spikes written to {output_path}")
+
+
+if __name__ == "__main__":
+    main()