socket.io-client

• https://www.npmjs.com/package/socket.io-client

npm install socket.io-client

As explained in the "What Socket.IO is not" section, the Socket.IO client is not a WebSocket implementation and thus will not be able to establish a connection with a WebSocket server, even with transports: ["websocket"]

engine.io-client:socket creating transport "polling" +0ms

socket.io-parser decoded 4{"message":"No auth token"} as {"type":4,"nsp":"/","data":{"message":"No auth token"}} +732ms

No auth token
Signature verification failed

client.on("connect_error", (err) => {
  console.log(`connect_error due to ${err.message}`);
});

Related

• wscat
• DEBUG=* node your_app.js

See also

• wscat, -c
• socket, socket.io-client