socket.io-client how to set request header when making connection

March 20, 2023 by Tarik

You can use extraHeaders option, if you are using socket.io-client >= 1.4.

For example:

var socket = io("http://localhost", {
  extraHeaders: {
    Authorization: "Bearer authorization_token_here"
  }
});

engine.io-client, which is a backend of socket.io-client, introduced extraHeaders support on 2015-11-28.