/// <reference types="node" />
import { EventEmitter } from 'events';
/**
 * @see https://github.com/nats-io/node-nats
 */
export declare class Client extends EventEmitter {
    /**
     * Create a properly formatted inbox subject.
     */
    createInbox(): string;
    /**
     * Close the connection to the server.
     */
    close(): void;
    /**
     * Flush outbound queue to server and call optional callback when server has processed
     * all data.
     */
    flush(callback?: Function): void;
    /**
     * Publish a message to the given subject, with optional reply and callback.
     */
    publish(callback: Function): void;
    publish(subject: string, callback: Function): void;
    publish(subject: string, msg: string | Buffer, callback: Function): void;
    publish(subject: string, msg?: string | Buffer, reply?: string, callback?: Function): void;
    /**
     * Subscribe to a given subject, with optional options and callback. opts can be
     * ommitted, even with a callback. The Subscriber Id is returned.
     */
    subscribe(subject: string, callback: Function): number;
    subscribe(subject: string, opts: any, callback: Function): number;
    /**
     * Unsubscribe to a given Subscriber Id, with optional max parameter.
     */
    unsubscribe(sid: number, max?: number): void;
    /**
     * Set a timeout on a subscription.
     */
    timeout(sid: number, timeout: number, expected: number, callback: (sid: number) => void): void;
    /**
     * Publish a message with an implicit inbox listener as the reply. Message is optional.
     * This should be treated as a subscription. You can optionally indicate how many
     * messages you only want to receive using opt_options = {max:N}. Otherwise you
     * will need to unsubscribe to stop the message stream.
     * The Subscriber Id is returned.
     */
    request(subject: string, callback: Function): number;
    request(subject: string, msg: string | Buffer, callback: Function): number;
    request(subject: string, msg?: string, options?: any, callback?: Function): number;
    /**
     * Publish a message with an implicit inbox listener as the reply. Message is optional.
     * This should be treated as a subscription. Request one, will terminate the subscription
     * after the first response is received or the timeout is reached.
     * The callback can be called with either a message payload or a NatsError to indicate
     * a timeout has been reached.
     * The Subscriber Id is returned.
     */
    requestOne(subject: string, msg: string | Buffer, options?: any, timeout?: number, callback?: Function): number;
    /**
     * Report number of outstanding subscriptions on this connection.
     */
    numSubscriptions(): number;
}