import { MessageEvent, ErrorEvent } from 'ws';
export declare class OkxSocketClient {
    private socket;
    private endpoint;
    private onOpen;
    private onMessage;
    private onClose;
    private onError;
    private lastMessageTime;
    private heatbeatInterval;
    private heartbeatTimer;
    constructor(endpoint: string, onOpen: () => void, onMessage: (event: MessageEvent) => Promise<void>, onClose: () => void, onError: (event: ErrorEvent) => void);
    connect(): Promise<void>;
    send(message: any): Promise<void>;
    close(): Promise<void>;
    startHeartbeat: () => void;
}