Support custom summarize timestamp column

README.md

@@ -52,8 +52,13 @@ Other demo entrypoints:
 - `python -m telemetry_window_demo.cli run-ai-demo`
 - `python -m telemetry_window_demo.cli run-rule-dedup-demo`
 - `python -m telemetry_window_demo.cli run-config-change-demo`
-
-That command reads `data/raw/sample_events.jsonl` and regenerates:
+
+Useful inspection commands:
+
+- `python -m telemetry_window_demo.cli summarize --input data/raw/sample_events.jsonl`
+- `python -m telemetry_window_demo.cli summarize --input events.csv --timestamp-col event_time`
+
+That command reads `data/raw/sample_events.jsonl` and regenerates:
 
 - `data/processed/features.csv`
 - `data/processed/alerts.csv`

src/telemetry_window_demo/cli.py

@@ -67,8 +67,13 @@ def build_parser() -> argparse.ArgumentParser:
         "summarize",
         help="Summarize an input event file.",
     )
-    summarize_parser.add_argument("--input", required=True, help="Path to .jsonl or .csv.")
-    summarize_parser.set_defaults(func=summarize_command)
+    summarize_parser.add_argument("--input", required=True, help="Path to .jsonl or .csv.")
+    summarize_parser.add_argument(
+        "--timestamp-col",
+        default=DEFAULT_TIMESTAMP_COLUMN,
+        help="Timestamp column name in the input event file.",
+    )
+    summarize_parser.set_defaults(func=summarize_command)
 
     plot_parser = subparsers.add_parser("plot", help="Render plots from CSV outputs.")
     plot_parser.add_argument("--features", required=True, help="Path to features.csv.")
@@ -174,10 +179,17 @@ def run_command(args: argparse.Namespace) -> None:
         print(f"     - {plot_path.name}")
 
 
-def summarize_command(args: argparse.Namespace) -> None:
-    events = normalize_events(load_events(args.input))
-    min_time = format_timestamp(events["timestamp"].min())
-    max_time = format_timestamp(events["timestamp"].max())
+def summarize_command(args: argparse.Namespace) -> None:
+    timestamp_col = _timestamp_column_config_value(
+        args.timestamp_col,
+        "timestamp-col",
+    )
+    events = normalize_events(
+        load_events(args.input, timestamp_col=timestamp_col),
+        timestamp_col=timestamp_col,
+    )
+    min_time = format_timestamp(events[timestamp_col].min())
+    max_time = format_timestamp(events[timestamp_col].max())
     top_event_types = events["event_type"].value_counts().head(5).to_dict()
     overall_error_rate = float(events["is_error"].mean()) if not events.empty else 0.0
 

tests/test_cli_errors.py

@@ -72,6 +72,36 @@ def test_main_reports_directory_input_without_traceback(tmp_path, capsys) -> Non
     assert "Traceback" not in stderr
 
 
+def test_main_reports_bad_summarize_timestamp_column_without_traceback(
+    tmp_path,
+    capsys,
+) -> None:
+    input_path = tmp_path / "events.csv"
+    input_path.write_text(
+        "event_type,source,target,status\n"
+        "2026-03-10T10:00:00Z,user_a,auth,ok\n",
+        encoding="utf-8",
+    )
+
+    with pytest.raises(SystemExit) as excinfo:
+        main(
+            [
+                "summarize",
+                "--input",
+                str(input_path),
+                "--timestamp-col",
+                "event_type",
+            ]
+        )
+
+    assert excinfo.value.code == 1
+    stderr = capsys.readouterr().err
+    assert stderr.startswith("error: ")
+    assert "timestamp-col" in stderr
+    assert "event_type" in stderr
+    assert "Traceback" not in stderr
+
+
 def test_main_reports_bad_plot_feature_table_without_traceback(tmp_path, capsys) -> None:
     features_path = tmp_path / "features.csv"
     features_path.write_text(

tests/test_cli_summarize.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+from telemetry_window_demo.cli import main
+
+
+def test_summarize_honors_configured_timestamp_column(tmp_path, capsys) -> None:
+    input_path = tmp_path / "events.csv"
+    input_path.write_text(
+        "event_time,event_type,source,target,status,severity\n"
+        "2026-03-10T10:00:10Z,login_success,user_a,auth,ok,low\n"
+        "2026-03-10T10:00:00Z,login_fail,user_b,auth,fail,high\n",
+        encoding="utf-8",
+    )
+
+    main(
+        [
+            "summarize",
+            "--input",
+            str(input_path),
+            "--timestamp-col",
+            "event_time",
+        ]
+    )
+
+    stdout = capsys.readouterr().out
+    assert "events: 2" in stdout
+    assert "time_range: 2026-03-10T10:00:00Z -> 2026-03-10T10:00:10Z" in stdout
+    assert "unique_sources: 2" in stdout
+    assert "overall_error_rate: 0.50" in stdout