So I have a scenario that demands I send events from a server to client. I had tried with Server Side Events but I had the issue that I had when I moved to Websockets. Because of this issue I move from Heroku to Render. The only solution was permanent connection which I never had on Heroku. The scenario is at every point in a mobile wallet transaction I inform the user/client what is going on. For example waiting for response, Enter your PIN.These messages deliver on local dev environment but nothing in production. These dynamic events are delivered to all connected clients whoes readyState OPEN.

interface CustomWebSocket extends WebSocket {
  clientId?: string;
}

const customWs = ws as CustomWebSocket;
    customWs.clientId = clientId;
    // Store the client
    clients.add(customWs);
//event webhook
  app.post('/api/v1/payment/momo-event-webhook', async (req: Request, res: Response) => {
    const event = req.body;

    // Relay the event to all connected clients
    const broadcast = (clients: Set<WebSocket>, message: any) => {
      clients.forEach((client) => {
        const id = (client as CustomWebSocket).clientId?.toString();
        const messageItem = JSON.stringify({ clientId: id, event: message });
        console.log(`Sending message to client: ${id}`);
        if (client.readyState === WebSocket.OPEN) {
          client.send(messageItem, (error) => {
            if (error) {
              console.error(`Error sending message to client: ${id}`, error);
            }
          });
        }
      });
    };

    broadcast(clients, event);

    res.status(200).json({ success: true, message: 'Event received' });
  });

This is the definition

export const supplyPaymentEvent = async (message: string) => {
  return await fetch(process.env.PAYMENT_EVENT_ENDPOINT as string, {
    method: 'POST',
    body: JSON.stringify({ state: message }),
    headers: { 'Content-Type': 'application/json' },
  });
};

Then is how I call it in various controllers

await supplyPaymentEvent('saving subscription');

Everybody asks why I created a route and a controller for this feature but I need to call it in places that could deliver it to the websocket. Perhaps a function approach will do but I don’t think that is my problem. I hope the issue is not from where I am trying to send the message