/**
 * Sets cache prevention headers to prevent CDN/proxy caching.
 * @param headers - The Headers object to set the cache prevention headers on.
 */
export declare function setCachePreventionHeaders(headers: Headers): void;
export declare function redirectWithFallback(redirectUri: string, headers?: Headers): Response;
export declare function errorResponseWithFallback(errorBody: {
    error: {
        message: string;
        description: string;
    };
}): Response;
type EvaluateRecentAuthParameters = {
    authTime: unknown;
    maxAgeSeconds: number;
    nowSeconds: number;
};
/**
 * Evaluate whether an authentication is recent enough.
 *
 * Fails closed: a missing or non-finite `authTime` is reported as stale. A
 * future `authTime` (clock skew) is treated as recent rather than stale, and
 * the `maxAge` boundary is inclusive.
 */
export declare function evaluateRecentAuth({ authTime, maxAgeSeconds, nowSeconds }: EvaluateRecentAuthParameters): {
    readonly authenticatedAt: null;
    readonly isStale: true;
} | {
    readonly authenticatedAt: Date;
    readonly isStale: boolean;
};
/**
 * Returns a function that can only be called once.
 * Subsequent calls will return the result of the first call.
 * This is useful for lazy initialization.
 * @param fn - The function to be called once.
 * @returns A function that can only be called once.
 */
export declare function lazy<TArgs extends unknown[], TResult>(fn: (...args: TArgs) => TResult): (...args: TArgs) => TResult;
export {};