diff --git a/trace_agg/src/trace_agg/cli.py b/trace_agg/src/trace_agg/cli.py
new file mode 100644
index 0000000..67dacd4
--- /dev/null
+++ b/trace_agg/src/trace_agg/cli.py
@@ -0,0 +1,48 @@
+import argparse
+import json
+from pathlib import Path
+from trace_agg.core import aggregate_traces
+
+
+def load_trace_data(input_path: Path):
+    if not input_path.exists():
+        raise FileNotFoundError(f"Input file not found: {input_path}")
+    with input_path.open('r', encoding='utf-8') as f:
+        data = json.load(f)
+    if not isinstance(data, list):
+        raise ValueError("Expected a list of TraceData objects in JSON input.")
+    required_fields = {"entry_time", "first_read_time", "baseline_recalc_time"}
+    for item in data:
+        if not required_fields.issubset(item.keys()):
+            raise ValueError(f"Missing fields in trace element: {item}")
+    return data
+
+
+def write_output(output_path: Path, delta_chain):
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    with output_path.open('w', encoding='utf-8') as f:
+        json.dump(delta_chain, f, indent=2)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Aggregate BPF trace data and compute delta chains."
+    )
+    parser.add_argument(
+        "--input", required=True, help="Path to input JSON file with TraceData events."
+    )
+    parser.add_argument(
+        "--output", default="output/delta_chain.json", help="Output path for delta chain JSON."
+    )
+
+    args = parser.parse_args()
+    input_path = Path(args.input)
+    output_path = Path(args.output)
+
+    trace_data = load_trace_data(input_path)
+    delta_chain = aggregate_traces(trace_data)
+    write_output(output_path, delta_chain)
+
+
+if __name__ == "__main__":
+    main()