import type { MessageAck } from "./client.js";
/**
 * Format a `MessageAck` as a single user-facing string.
 *
 * - `ok` ack → `reply` content (or empty string if absent).
 * - Failed ack → `"Error[ (status)]: <error or 'unknown'>"`.
 */
export declare function formatAckReply(ack: MessageAck): string;