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Periphery

Observability

Use --write-metrics to export a metrics snapshot alongside the normal scan results. Collecting a snapshot on each CI scan lets you continuously monitor unused code in large codebases and see how it changes over time.

Terminal window
periphery scan --write-metrics scan.prom

The default is Prometheus text format 1.0.0. For OpenMetrics text format 1.0.0, add --metrics-format openmetrics. Both work with every results format and can be configured using write_metrics and metrics_format in .periphery.yml.

Metric Meaning
periphery_scan_source_lines Scanned LOC, excluding comments and blank lines.
periphery_scan_results Number of reported results.
periphery_scan_removable_lines Removable LOC, counting overlapping ranges once and excluding partial line edits.
periphery_scan_unused_ratio Removable LOC divided by scanned LOC: 0.075 means 7.5%. Zero when scanned LOC is zero.
periphery_scan_baseline_entries Unique identifiers in the input baseline, emitted only when --baseline is used. Includes stale entries; it is not the count of findings suppressed.

All metrics are gauges. Findings and removable LOC reflect baseline and report filtering; scanned LOC covers the entire scan.