/**
 * Durable outbound queue (crash recovery): JSON file under agent internal dir.
 */
import type { OutboundMessage } from '../transport-types.js';
export interface PendingOutbound {
    id: string;
    enqueuedAt: number;
    message: OutboundMessage;
}
export declare class OutboundPersistStore {
    private readonly filePath;
    private pending;
    constructor(agentDir: string);
    private load;
    private flush;
    enqueue(message: OutboundMessage): string;
    ack(id: string): void;
    peek(): readonly PendingOutbound[];
}