What is the use of path for socket.io, how is that different from custom namespace

[Zeus-Iqd]

const socket = io('http://myserver/admin', {
path: '/mypath'
});
socket.io doc said with that code the socket connects to the admin namespace, with the custom path mypath. But what the use of path here? Can't namespace alone do the job?

Or under what circumstance do I need to set custom path?

[darrachequesne]

Hi! The path option refers to the request path. With path: '/mypath', you will see in your network panel HTTP requests like:

GET http://myserver/mypath/?EIO=4&...'

The path option defaults to /socket.io/:

GET http://myserver/socket.io/?EIO=4&...'

Reference: https://socket.io/docs/v4/client-options/#path

On the other hand, the namespace (the /admin in your example) is the part of your application you'd like to connect to. It provides a way to split your application logic into independent modules, while using the same WebSocket connection under the hood (multiplexing).

Reference: https://socket.io/docs/v4/namespaces/

With io('http://myserver/admin'), you reach to /admin namespace, with io('http://myserver') you reach the main namespace. The data will not be found in the request URL, but in the payload.

Reference: https://socket.io/docs/v4/socket-io-protocol/#format