Auth0 + React + Encore App Example

This is an example of how to do user authentication using Auth0 in an Encore app. Check out the Use Auth0 with your app guide to learn more about this example.

For this example the login/logout flow is done through Encore and the frontend is React + React Router. Take a look at auth0-react-sdk for an example where the login/logout flow is abstracted away by the Auth0 React SDK.

Cloning the example

When you have installed Encore, you can create a new Encore application and clone this example by running this command:

encore app create my-app --example=auth0

Auth0 Credentials

Create an Auth0 account if you haven't already. Then, in the Auth0 dashboard, create a new Single Page Web Applications.

Next, go to the Application Settings section. There you will find the Domain, Client ID, and Client Secret that you need to communicate with Auth0. Copy these values, we will need them shortly.

A callback URL is where Auth0 redirects the user after they have been authenticated. Add http://localhost:3000/callback to the Allowed Callback URLs. You will need to add more URLs to this list when you have a production or staging environments.

The same goes for the logout URL (were the user will get redirected after logout). Add http://localhost:3000/ to the Allowed Logout URLs.

Config and secrets

In backend/auth/auth-config.cue, replace the values for the ClientID and Domain that you got from the Auth0 dashboard.

The ClientSecret is especially sensitive and should not be hardcoded in your code/config. Instead, you should store that as an Encore secret.

From your terminal (inside your Encore app directory), run:

$ encore secret set --prod Auth0ClientSecret

Now you should do the same for the development secret. The most secure way is to set up a different Auth0 application and use that for development. Depending on your security requirements you could also use the same secret for development and production.

Once you have a client secret for development, set it similarly to before:

$ encore secret set --dev Auth0ClientSecret

Developing locally

Run your Encore backend:

encore run

In a different terminal window, run the React frontend using Vite:

cd frontend
npm install
npm run dev

Open http://localhost:3000 in your browser to see the result.

Encore's Local Development Dashboard

While encore run is running, open http://localhost:9400/ to view Encore's local developer dashboard. Here you can see the request you just made and a view a trace of the response.

Generating a request client

Keep the contract between the backend and frontend in sync by regenerating the request client whenever you make a change to an Encore endpoint.

npm run gen # Deployed Encore staging environment
# or
npm run gen:local # Locally running Encore backend

Deployment

Encore

Deploy your backend to a staging environment in Encore's free development cloud:

git add -A .
git commit -m 'Commit message'
git push encore

Then head over to the Cloud Dashboard to monitor your deployment and find your production URL.

From there you can also see metrics, traces, connect your app to a GitHub repo to get automatic deploys on new commits, and connect your own AWS or GCP account to use for deployment.

React on Vercel

Create a repo and push the project to GitHub.
Create a new project on Vercel and point it to your GitHup repo.
Select frontend as the root directory for the Vercel project.

CORS configuration

If you are running into CORS issues when calling your Encore API from your frontend then you may need to specify which origins are allowed to access your API (via browsers). You do this by specifying the global_cors key in the encore.app file, which has the following structure:

global_cors: {
  // allow_origins_without_credentials specifies the allowed origins for requests
  // that don't include credentials. If nil it defaults to allowing all domains
  // (equivalent to ["*"]).
  "allow_origins_without_credentials": [
    "<ORIGIN-GOES-HERE>"
  ],
        
  // allow_origins_with_credentials specifies the allowed origins for requests
  // that include credentials. If a request is made from an Origin in this list
  // Encore responds with Access-Control-Allow-Origin: <Origin>.
  //
  // The URLs in this list may include wildcards (e.g. "https://*.example.com"
  // or "https://*-myapp.example.com").
  "allow_origins_with_credentials": [
    "<DOMAIN-GOES-HERE>"
  ]
}

More information on CORS configuration can be found here: https://encore.dev/docs/develop/cors