> For the complete documentation index, see [llms.txt](https://docs.relysia.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.relysia.com/realtime-transaction-notification/setup-and-configuration.md).

# Setup and Configuration

We require two packages to create a simple client application to receive notifications:\
1\. [socket.io-client](https://www.npmjs.com/package/socket.io-client) (For connectivity)\
2\. HTTP [client-library](https://www.npmjs.com/package/axios) (For HTTP sending requests)

A typical simple application to get notification enabled is as depicted below.\
It's a two-step process.

1. Authentication (/v1/auth) user
2. Listen the specific event to receive relevant message\data\
   -Listen for event the "**notification**" to receive transactional notifications\
   -Listen for event the "**balance**" to receive balance changes\
   -Listen for event the "**history**" to receive history changes

```
const axios = require('axios').default;
const { io } = require('socket.io-client')
            
const relysiaEndpoint = 'api.relysia.com';

(async () => {
    // Login into account
    const loginObject = await axios.post(`https://${relysiaEndpoint}/v1/auth`, {email: "user@abc.com", password: "password"});
    console.log('Login completed', loginObject.data);
    // Connect websocket for this account
    const socket = io(`wss://${relysiaEndpoint}`, {
        extraHeaders: {
            authToken: loginObject.data.data.token,
        },    
        transports: ['websocket', 'polling']
    });

    socket.on('error', function(error) {
        console.log("Connection Error: " + error.toString());
    });

     // Listen for message and log them as notification arrive
    socket.on('notification', function (message) {
        console.log('event received', message);
    })

    // listen for balance and log them on balance arrive
    socket.on('balance', function (balance) {
        console.log('event received', balance);
    })

    // listen for history and log them on history arrive
    socket.on('history', function (history) {
        console.log('event received', history);
    })
    
    

    socket.on('connect', function(connection) {
        console.log('WebSocket Client Connected');
        socket.on('close', function() {
            console.log('echo-protocol Connection Closed');
        });
    });
})()
```