type MetricName = 'LCP' | 'INP' | 'CLS' | 'FCP' | 'TTFB';
interface ReportedMetric {
    name: MetricName;
    value: number;
    rating: string;
    route: string;
}
interface VitalsReporter {
    report(metric: ReportedMetric): void;
}
interface WebVitalsBeaconProps {
    reporter: VitalsReporter;
}
declare function reportWebVitals(reporter: VitalsReporter): Promise<void>;
declare function WebVitalsBeacon({ reporter }: WebVitalsBeaconProps): null;

export { type ReportedMetric, type VitalsReporter, WebVitalsBeacon, type WebVitalsBeaconProps, reportWebVitals };