websocket connect issues in my railway deployed app

[halcyon token]

I've a Nest.js app that is working fine on local and Docker, but when I deploy it to Railway, it gives me an error.
I've tried every suggestion from AI to resolve it, but it's not working

I've tried using the internal address, and right now I've set public URL of the backend to connect to it, but still I'm seeing this error

WebSocket connection to 'wss://{backend-url}.up.railway.app/socket.io/?EIO=4&transport=websocket'

the error redirects me to this part:

class X extends K { createSocket(t, e, s) { return $ ? new W(t,e,s) : e ? new W(t,e) : new W(t) } doWrite(t, e) { this.ws.send(e) } }

Can you help me solve it?

[slim otter]

Hi @halcyon token , it may be related to CORS. Can you try to add something like

@WebSocketGateway({
  cors: {
    origin: '{backend-url}.up.railway.app'
  },
})

[halcyon token]

I have origin in env file

FRONTEND_URL="https://{frontend}.up.railway.app"

do i need to backend here as well?

`const websocketOrigins = getAllowedOrigins();
const resolvedOrigins =
websocketOrigins.length > 0 ? websocketOrigins : ['http://localhost:3000'];

@WebSocketGateway({
cors: {
origin: resolvedOrigins,
credentials: true,
},
namespace: '/',
transports: ['websocket', 'polling'],
})
@UseGuards(WsJwtGuard)
export class EventsGateway
implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect
{`

I've added backend url here as well but still same error

[slim otter]

Can you try origin: "*" just to see if the issue is coming from there ?
What do you see in your browser network tab with Socket filter ?