/**
 * SSEListener - Real-time event stream listener for the MCP server.
 *
 * Connects to the backend's SSE endpoint (`GET /v1/events/stream`)
 * and dispatches transfer and broadcast events as they arrive.
 * Auto-reconnects with exponential backoff on disconnect.
 * Falls back to polling after 3 consecutive connection failures.
 */
export interface SSEListenerOptions {
    apiBase: string;
    apiKey: string;
    agentId?: string;
    /** Called when a transfer event fires (created, downloaded, deleted). */
    onTransferEvent: (type: string, data: unknown) => void;
    /** Called when a broadcast event fires. */
    onBroadcast?: (data: unknown) => void;
    /** Called when a real-time message event fires (Phase A v0.1 — message.created). */
    onMessageEvent?: (type: string, data: unknown) => void;
    /** Called when SSE gives up after consecutive failures. */
    onFallbackToPolling?: () => void;
    /** Max consecutive failures before fallback. Default: 3 */
    maxConsecutiveFailures?: number;
    /** Initial backoff delay in ms. Default: 3000 */
    initialBackoffMs?: number;
    /** Max backoff delay in ms. Default: 60000 */
    maxBackoffMs?: number;
}
export declare class SSEListener {
    private apiBase;
    private apiKey;
    private agentId?;
    private onTransferEvent;
    private onBroadcast?;
    private onMessageEvent?;
    private onFallbackToPolling?;
    private maxConsecutiveFailures;
    private initialBackoffMs;
    private maxBackoffMs;
    private consecutiveFailures;
    private running;
    private abortController;
    private reconnectTimer;
    constructor(opts: SSEListenerOptions);
    /**
     * Build the SSE endpoint URL.
     */
    private buildUrl;
    /**
     * Calculate backoff delay for the current failure count.
     */
    private getBackoffMs;
    /**
     * Connect to the SSE endpoint and start reading events.
     */
    private connect;
    /**
     * Parse a raw SSE event block into type + data and dispatch.
     */
    private processRawEvent;
    /**
     * Schedule a reconnection attempt after backoff delay.
     */
    private scheduleReconnect;
    /**
     * Start listening to the SSE stream.
     */
    start(): void;
    /**
     * Stop listening and clean up.
     */
    stop(): void;
}