/** Shared HTTP utilities for crawling and discovery. */
/**
 * Check if a URL returns a successful response.
 *
 * HEAD first, because it is cheap, then a one-byte ranged GET when HEAD fails.
 * Some hosts serve a document happily on GET and answer HEAD with a 404 -
 * api.fmdb.pro does exactly that for its OpenAPI document - and reporting those
 * as missing sends a maintainer chasing a source that was never gone.
 */
export declare function urlExists(url: string): Promise<{
    ok: boolean;
    contentType?: string;
}>;
/** Fetch text content from a URL, returning null on failure. Rejects responses over 10MB. */
export declare function fetchText(url: string, timeoutMs?: number): Promise<string | null>;