import WebSocket from 'isomorphic-ws';
/** Should be one WS key per unique URL */
export declare const WS_KEY_MAP: {
    readonly spotPublicV1: "spotPublicV1";
    readonly spotPrivateV1: "spotPrivateV1";
    readonly futuresPublicV1: "futuresPublicV1";
    readonly futuresPrivateV1: "futuresPrivateV1";
};
/** This is used to differentiate between each of the available websocket streams */
export type WsKey = (typeof WS_KEY_MAP)[keyof typeof WS_KEY_MAP];
/**
 * Normalised internal format for a request (subscribe/unsubscribe/etc) on a topic, with optional parameters.
 *
 * - Topic: the topic this event is for
 * - Payload: the parameters to include, optional. E.g. auth requires key + sign. Some topics allow configurable parameters.
 */
export interface WsTopicRequest<TWSTopic extends string = string, TWSPayload = any> {
    topic: TWSTopic;
    payload?: TWSPayload;
}
/**
 * Conveniently allow users to request a topic either as string topics or objects (containing string topic + params)
 */
export type WsTopicRequestOrStringTopic<TWSTopic extends string, TWSPayload = any> = WsTopicRequest<TWSTopic, TWSPayload> | string;
export interface MessageEventLike {
    target: WebSocket;
    type: 'message';
    data: string;
}
export declare function isMessageEvent(msg: unknown): msg is MessageEventLike;
/**
 * #305: ws.terminate() is undefined in browsers.
 * This only works in node.js, not in browsers.
 * Does nothing if `ws` is undefined. Does nothing in browsers.
 */
export declare function safeTerminateWs(ws?: WebSocket | any, fallbackToClose?: boolean): boolean;