import type { LanguageDetectorOptions } from '../runtime/i18n/instance';
/**
 * Detect language from request using the same detection logic as i18next
 * This ensures consistency between server-side and client-side detection
 */
export declare function detectLanguageFromRequest(req: {
    url: string;
    headers: {
        get: (name: string) => string | null;
    } | Headers;
}, languages: string[], detectionOptions?: LanguageDetectorOptions): string | null;