Install

npm install nats.ws
npm install websocket

Demo Implementation

• For node, you need to shim the websocket library. Otherwise, you will get ReferenceError: WebSocket is not defined.

• Execute: node wss-subscribe-publish.mjs

  // RUN: node wss-subscribe-publish.mjs
  
  // Shim is only required if you run this script using node command.
  //  Shim is neither need if this script is called from Nextjs api framework.
  // Shim the websocket. Otherwise, it will complain ReferenceError: WebSocket is not defined.
  import w3c from "websocket";
  globalThis.WebSocket = w3c.w3cwebsocket;
  
  import { connect } from "nats.ws";
  
  async function main() {
      try {
          const nc = await connect({ servers: ["wss://rollingweddingpictures.com"] });
          console.log(`Connected to ${nc.getServer()}`);
  
          const subjectId = "chat.room";
  
          // Example: Subscribe(listen) to a subject
          const sub = nc.subscribe(subjectId);
          (async () => {
              console.log(`Subscribe to ${subjectId}`)
              for await (const m of sub) {
                  console.log(`Received message: ${m.string()}`);
              }
          })();
  
          // Example: Publish(Post) to a subject
          const dateTime = new Date().toLocaleTimeString();
          const message = `${dateTime}: ${subjectId}: Client WSS says: Hello NATS!`;
          nc.publish(subjectId, message);
          console.log(`Published to ${subjectId}`);
  
          // Clean up: Close everything.
          await nc.drain();
  
      } catch (_err) {
          console.log(`error connecting to ${JSON.stringify(_err)}`);
      }
  }
  
  await main();