---
title: "Introduction"
url: https://docs.catalyst.zoho.com/en/tutorials/third-party-auth/nodejs/introduction/
description: "Integrate Auth0 SPA authentication service with basic web applications hosted on Catalyst using OpenID Connect and 0Auth2.0 authentication protocols."
last_updated: 2026-08-17T12:16:04Z
service: All Services
type: tutorial
related_links:
  - name: "Project Directory Structure"
    url: /en/cli/v1/project-directory-structure/introduction/
  - name: "Upload Object to Bucket"
    url: /en/cloud-scale/help/stratus/objects/upload-object/
  - name: "Stratus SDK"
    url: /en/sdk/nodejs/v2/cloud-scale/stratus/overview/
  - name: "Stratus API"
    url: /en/api/code-reference/cloud-scale/stratus/get-all-buckets/#GetAllBuckets
---

# Authenticate Catalyst Apps with Auth0

### Introduction

In this tutorial, we will be integrating **Auth0's Single Page Application** (SPA) authentication service with applications created or hosted on Catalyst. This integration employs industry standard **OpenID Connect** and **OAuth 2.0** authentication protocols making it possible to add end-users to Catalyst applications using third-party authentication services.

[Auth0](https://auth0.com/), much like Catalyst Authentication, is a cloud-based identity and access management platform that offers developers to add end-users to their application through Social Logins, multi-factor authentication, and more.

The client of your application will be rendered in the following manner:
![catalyst_tutorials_third_party_app_deployed](https://catalyst-docs-development.zohostratus.in/images/tutorials/third-party-auth/catalyst_tutorials_third_party_app_deployed.webp)

The logic of this application is coded by employing the following Catalyst services and its respective components:

* [**Catalyst Serverless**](https://docs.catalyst.zoho.com/en/serverless/):
    - [AdvancedIO Function](https://docs.catalyst.zoho.com/en/serverless/help/functions/advanced-io/): Will contain the logic validate Auth0 access tokens and fetch user details.

* [**Catalyst CloudScale**](https://docs.catalyst.zoho.com/en/cloud-scale/):
    - [Authentication](https://docs.catalyst.zoho.com/en/cloud-scale/help/authentication/introduction/): We will implement [Third-party Authentication type](https://docs.catalyst.zoho.com/en/cloud-scale/help/authentication/third-party-authentication/introduction/) to allow third-party (**Auth0**) service to fulfill the authentication requirement of the Catalyst Application.
    - [Web Client Hosting](https://docs.catalyst.zoho.com/en/cloud-scale/help/web-client-hosting/introduction/): We will host the client of the application using this component.

You will be using the [Catalyst web console](https://console.catalyst.zoho.com/) and the [Catalyst Command Line Interface](https://docs.catalyst.zoho.com/en/cli/v1/cli-command-reference/) (**CLI**) to build this application.

> **Note:** You will be given the code for the files to be included in the function and client components in this tutorial. You will just need to copy the provided code and paste it into the appropriate files as directed.

### Application Workflow

The workflow of how an end-user is authenticated using Auth0 and added as a user to your Catalyst application is detailed below:

1. The end-user will be provided the option to log in to the application.
2. After the user attempts to log in, they will be directed to the login elements generated by the Auth0 service. Here, the end-user will be provided the option to **Signup** or **Sign** using *Google social login*, or by providing their user information such as their name, email address.
3. After the end-user is authenticated by the Auth0 service, the details will be forwarded to the client with an authorization code.
4. The authentication logic in the backend function will be triggered and an API call will be made to the Auth0 service using the authorization code.
5. After this API call, the required user details will be passed to Catalyst, and a Catalyst custom token will be generated.

> **Info:** The code to generate custom server token is also available in this [help section](https://docs.catalyst.zoho.com/en/sdk/nodejs/v2/cloud-scale/authentication/third-party-server-token/) and in the Catalyst console.

6. Now, the user details will be made available in the client and in the *User Management* section of the *Catalyst Authentication* component. The end-users' details along with the token information will also be stored in the browser cookie through the Web SDK, to ensure the session is maintained.
7. The user will now access your application through its endpoints. The Catalyst Security Engine ensures that all the components associated with the application are accessed securely by end-users.

> **Note:** The token will only remain valid for **one hour**. After that, the steps from **5** to **7** will be repeated in the background.

After the end-user is authenticated and the login session continues to persist, they can securely access all the end points of your application until the token's expiration time.