import { type TierResult } from "./fetch-utils.js";
export declare function isYouTubeHost(url: string): boolean;
/** Pull the 11-char video id from any common YouTube URL form. */
export declare function extractVideoId(url: string): string | null;
/**
 * Best-effort YouTube transcript fetch. Returns null (caller falls through to
 * the normal cascade) if the feature is disabled, the URL has no video id, no
 * captions are available, or the unofficial endpoints fail/shape-change.
 */
export declare function youtubeFetch(url: string, maxChars?: number): Promise<TierResult | null>;