---
title: "WebSocket Connection"
url: https://docs.catalyst.zoho.com/en/sdk/nodejs/v2/cloud-scale/data-streams/websocket-connection/
description: "This page describes how to connect to a Data Streams channel over WebSocket and subscribe to real-time data in your Node.js application with sample code snippets."
last_updated: 2026-10-05T15:13:57Z
service: Cloud Scale
type: general
related_links:
  - name: "Data Streams"
    url: /en/cloud-scale/help/data-streams/introduction
---

# WebSocket Connection

[Catalyst Data Streams](https://docs.catalyst.zoho.com/en/cloud-scale/help/data-streams/introduction/) enables clients to receive real-time data by establishing a WebSocket connection to a channel. The client listens for published messages and processes them as they are received.

To subscribe to a channel, you must first generate a token pair, then create a WebSocket client with the token credentials, and finally set event handlers to handle incoming messages.

The `datastreams` reference used in the code below is the [component instance](https://docs.catalyst.zoho.com/en/sdk/nodejs/v2/cloud-scale/data-streams/get-component-instance) created earlier.

### Establish WebSocket Connection

You must initially generate a token pair using the `getTokenPair()` method as shown below. Then, create a WebSocket client by passing the token credentials to the `DataStreamsWebSocket` constructor.

> **Note:**
* **CRICKET_CHANNEL_ID** - Replace with your actual Channel ID which you can get from Dashboard → General Details section.
* **userId** - A unique identifier used to generate WebSocket credentials for that subscriber.
* **subscribe("0")** - This subscribes the client to live data.

```javascript
//Generate token pair
const response = await datastreams.getTokenPair(CRICKET_CHANNEL_ID, {
  userId: "userId"
});

//Create WebSocket client
const socket = new DataStreamsWebSocket({
  url: response.url,
  zuid: response["wss-id"],
  key: response.key,
  enableLogging: true
});

//Handling WebSocket events
socket.on("open", () => {
  console.log("WebSocket connection opened");
  socket.subscribe("0"); //Subscribe to live data
});

socket.on("message", (data) => {
  console.log("WebSocket message received:", data);
  socket.sendAck(); //Acknowledge to receive next message
});

socket.on("error", (error) => {
  console.error("WebSocket error:", error);
});

socket.on("close", () => {
  console.log("WebSocket connection closed");
});
```