import { TTIReportCallback } from '../types/index';
/**
 * Calculates the [TTI](https://web.dev/tti/) value for the current page and
 * calls the `callback` function once the value is ready, along with the
 * relevant `paint` performance entry used to determine the value. The reported
 * value is a `DOMHighResTimeStamp`.
 */
export declare const onTTI: (onReport: TTIReportCallback) => void;