export interface RateLimiterOptions {
    limit: number;
    window: number;
    storage?: 'memory' | 'redis';
    redisClient?: any;
}
/**
 * Advanced Rate Limiter for API protection.
 * Returns true if allowed, false if rate limited.
 */
export declare function checkRateLimit(key: string, options: RateLimiterOptions): Promise<{
    allowed: boolean;
    remaining: number;
    reset: number;
}>;