import type { SpecUsageEvent, SpecUsageMetrics, SpecObservabilityReport, Period, BuildReportOptions } from '../../types/index.js';
export declare function filterByPeriod(events: readonly SpecUsageEvent[], period: Period): SpecUsageEvent[];
/**
 * Aggregate a flat event list into per-spec metrics.
 */
export declare function aggregateBySpec(events: readonly SpecUsageEvent[]): SpecUsageMetrics[];
export declare function buildObservabilityReport(opts: BuildReportOptions): SpecObservabilityReport;
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