/**
 * Transport — abstract I/O layer for JSON-RPC message exchange.
 *
 * Decouples the agent protocol handler from the physical transport
 * (stdin/stdout, WebSocket, Unix Domain Socket, etc.).
 *
 * Each transport reads incoming JSON-RPC messages and emits them
 * to a registered handler; outgoing messages are sent via send().
 */
import type { Transport } from "../transport/io-transport.js";
export type { Transport } from "../transport/io-transport.js";
/**
 * Line-delimited JSON over stdin/stdout.
 * Each line on stdin is a JSON message; each send() writes one JSON line to stdout.
 * All diagnostic logging goes to stderr.
 */
export declare class StdioTransport implements Transport {
    private messageHandler;
    private closeHandler;
    private verbose;
    constructor(opts?: {
        verbose?: boolean;
    });
    onMessage(handler: (msg: unknown) => void): void;
    onClose(handler: () => void): void;
    send(msg: unknown): void;
    start(): void;
    close(): void;
    private log;
}
