No

You can still connect to another socket in frontend.

To create a websocket server, you'll have to use something else like javascript hosted on a VPS or some other serverless service

You can, but not as a supported Next.js feature. I'm doing so in my current project.

The client part of the websocket works as ususal with next.js, if a bit tedious to implement so it doesn't interfere with react states.

The server-side part is trickier. You will have to run a dedicated socket server outside of next.js. If you're with vercel, you'll have to host the socket server separately on a vps or something of the like.

I'm self-hosting, so I included everything in the same project, but the persistent socket server is compiled and run separately alongside the next.js app.

TLDR: it can be done, but a bit more involved than regular next.js use cases.

(edit) Basically, just what the previous poster said, but a bit more in detail.

thank you for your help. Where can I get a simple project including it?