const ws = new WebSocket(url, protocols?);

// properties
ws.readyState        // 0..3
ws.bufferedAmount     // bytes queued, not yet sent
ws.protocol           // negotiated subprotocol
ws.binaryType         // "blob" | "arraybuffer"

// methods
ws.send(data);          // string | Blob | ArrayBuffer | TypedArray
ws.close(code?, reason?);

// events
ws.onopen / onmessage / onclose / onerror

import { WebSocketServer } from "ws";
const wss = new WebSocketServer({ port, server?, path? });

wss.on("connection", (ws, req) => { … });
wss.clients          // Set of connected sockets

ws.send(data, { binary });
ws.ping() / ws.pong();
ws.terminate();      // hard close, no handshake
ws.on("message" | "close" | "pong" | "error", fn);