Vanilla.js embedded login quickstart

This guide walks you through integrating Frontegg’s login box into your JavaScript app, with built-in support for Sign In, Sign Up, SSO, and automatic redirects—all in just a few lines of code.

Check out the sample package on GitHub

Getting your Frontegg subdomain and `clientId`

Frontegg creates a unique subdomain and client id for every environment created on the account. In order to retrieve the clientId subdomain that will act as the baseUrl in the integration, navigate to your workspace Keys & domains menu, and copy the Frontegg domain and clientId.

Step 1: Adding Frontegg to your app

Frontegg can be added to your app via npm / script on your application head.

npm install @frontegg/js

Step 2: Configure

Frontegg works with Context options and needs to be initialized with this context. In order to initialize Frontegg use the following code snippet

See contextOptions for more information.

import {initialize} from "@frontegg/js"

const style = document.createElement('style');
style.setAttribute('type', 'text/css');
style.innerHTML = '';
document.getElementsByTagName('head')[0].appendChild(style);


const app = initialize({
  contextOptions: {
    baseUrl: "https://[YOUR_SUBDOMAIN].frontegg.com", //set your Frontegg environment domain and client ID here
    appId: '[YOUR-APP-ID]'
  },
  authOptions: {
    keepSessionAlive: true // Keeps the session alive by refreshing the JWT in the background
  },
  hostedLoginBox: false
})

See keepSessionAlive and hostedLoginBox for more information.

Add the representative HTML button that will redirect the UI to the login page. Clicking on the button should take you to the login dialog.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        button {
            border-radius: 4px;
            background: dodgerblue;
            color: white;
            border: 0;
            padding: 8px 16px;
        }
    </style>
</head>
<body>

<div id="app-root" style="display: none">
    <h1>This is Frontegg Integration in Vanilla Javascript </h1>
    <div id="user-container">
    </div>
    <br/>
    <a fe-state="isAuthenticated" href="/account/logout"><button>Logout</button></a>
    <a fe-mode="embedded" fe-state="!isAuthenticated" href="/account/login"><button>Login</button></a>
</div>
<script src="/bundle.js"></script>
</body>
</html>

Step 3: Get the user context

The user context is available from the Frontegg app. Upon initialization, you can subscribe to state notifications which will include whether the user is authenticated or not and what is the JWT of the user.

In order to subscribe to user state notifications add the following code snippet:

import {initialize} from "@frontegg/js"

const style = document.createElement('style');
style.setAttribute('type', 'text/css');
style.innerHTML = '';
document.getElementsByTagName('head')[0].appendChild(style);


const app = initialize({
  contextOptions: {
    baseUrl: "https://[YOUR_SUBDOMAIN].frontegg.com", //set your Frontegg environment domain and client ID here
  },
  hostedLoginBox: false
})

app.store.subscribe(() => {
  const state = app.store.getState();
  if (state.auth.user) {
    document.getElementById('user-container').innerText = state.auth.user.email;
  } else {
    document.getElementById('user-container').innerText = 'Not Authenticated'
  }

  document.getElementById('app-root').style.display = state.auth.isLoading ? 'hidden' : 'block'


  let styleHtml = ''
  if (state.auth.isAuthenticated) {
    styleHtml += '[fe-state="isAuthenticated"] { }';
    styleHtml += '[fe-state="!isAuthenticated"] { display: none; }';
  } else {
    styleHtml += '[fe-state="isAuthenticated"] { display: none; }';
    styleHtml += '[fe-state="!isAuthenticated"] { }';
  }
  style.innerHTML = styleHtml;
})

Great, Frontegg is now integrated with your app!