/**
 * Generate signature for API requests
 *
 * @param payload - Request payload
 * @param apiKey - API key
 * @returns Generated signature
 */
export declare function generateSignature(payload: Record<string, any>, apiKey: string): string;
/**
 * Verify webhook signature
 *
 * @param payload - Webhook payload
 * @param signature - Signature from webhook headers
 * @param apiKey - API key
 * @returns Whether the signature is valid
 */
export declare function verifyWebhookSignature(payload: string, signature: string, apiKey: string): boolean;