import type { UUIDTypes } from 'uuid';
/**
 * Generates an idempotency key.
 *
 * @param value - Value to generate the key from. If provided, the key will be generated using UUID v5 with the given value and namespace.
 * @param namespace - The namespace to use for UUID v5 generation. Defaults to `uuid.v5.URL`.
 * @returns The generated idempotency key. If `value` is provided, a UUID v5 key is generated; otherwise, a UUID v4 key is generated.
 */
export declare function generateIdempotencyKey(value?: string, namespace?: UUIDTypes): string;