/**
 * Verify webhook signature
 * @param payload - Raw request body (string, Buffer, or parsed JSON object)
 * @param signature - Signature from X-Sinlyxe-Signature header
 * @param secret - Your webhook secret
 * @returns True if signature is valid
 */
export function verifyWebhook(payload: string | Buffer | Record<string, unknown>, signature: string, secret: string): boolean;

/**
 * Create webhook signature (for testing purposes)
 * @param payload - Payload to sign
 * @param secret - Webhook secret
 * @returns Signature in format "sha256=<hex>"
 */
export function createWebhookSignature(payload: string | Record<string, unknown>, secret: string): string;