/**
 * Generates VAPID keys for Web Push
 * @returns Object containing public and private keys in base64url format
 */
export declare function generateVAPIDKeys(): {
    publicKey: string;
    privateKey: string;
};
/**
 * Generates VAPID headers for a Web Push request
 * @param audience - Origin of the push service
 * @param subject - URL or mailto: of the application server
 * @param publicKey - VAPID public key
 * @param privateKey - VAPID private key
 * @param contentEncoding - Content encoding type
 * @param expiration - Optional expiration timestamp
 * @returns Object with required authorization headers
 */
export declare function getVapidHeaders(audience: string, subject: string, publicKey: string, privateKey: string, contentEncoding: string, expiration?: number): {
    Authorization: string;
    'Crypto-Key'?: string;
};