Pre-authenticated URLs

Use the pre-authenticated URLs feature to open a website from a native app in an authenticated state.

Pre-authenticated URLs is a feature that enables single sign-on (SSO) from a mobile application to a website. It allows users who are authenticated on a mobile application to open a website in an authenticated state.

An example use case for a pre-authenticated URL is opening a web application in a WebView.

Pre-requisites

To use pre-authenticated URLs, you must have the following:

• An Authgear application of type Native app.

• A second Authgear application that has pre-authentication URLs enabled.

How to Implement Pre-authentication URLs in your application

Step 1: Enable SSO in Native App client

First, ensure your mobile application uses an Authgear application with the Native App.

Your application must also enable SSO to allow pre-authenticated URLs to work. You can enable SSO by isSSOEnabled: true in the configure() method of Authgear SDK.

authgear
  .configure({
    clientID: '<CLIENT_ID>',
    endpoint: '<AUTHGEAR_PROJECT_URL>',
    isSSOEnabled: true,
  })

Step 2: Add Allowed Origin to Web App Client

Next, add an allowed origin to the web application client in Authgear. Navigate to Applications in the Authgear Portal, select the web application client, and scroll to the Allowed Origins section. Then, add the origin you wish to use for Pre-authentication URLs. Note that the origin should be of the format "protocol (scheme) + domain + port". For example, if the mobile application wants to open https://www.mywebapp.com/home?key=value, the origin must be https://www.mywebapp.com.

Step 3: Generate Pre-Authenticated URL

The Pre-Authenticated URL is a link that the Authgear SDK can generate for a mobile client that has the Pre-Authenticated URLs feature enabled. Your mobile application can open the Pre-Authenticated URL in a web view for users to start browsing the origin in an authenticated state.

To generate the Pre-Authenticated URL, call the makePreAuthenticatedURL() method of the Authgear SDK as shown below:

const url = await authgear.makePreAuthenticatedURL({
    webApplicationClientID: "YOUR_WEB_APP_CLIENT_ID", // Replace with you web app client id
    webApplicationURI: "YOUR_WEB_APP_URI", // Replace with you web app uri
  });

The makePreAuthenticatedURL() method accepts an object as a parameter. Inside the object, you should provide your web application's client ID and redirect URI.

The URL in YOUR_WEB_APP_URI should be a page on the web application that calls the authenticate() method of Authgear SDK with isSSOEnabled: true (or a page that initiates an authorization request) .

Step 4: Open Pre-Authenticated URL in a WebView

After the makePreAuthenticatedURL() return the URL, your mobile application should open the URL in a WebView. From there, users should be able to continue their current authenticated session (from the mobile app) on the web application.

The following code sample shows how to open the pre-authenticated URL using the Linking.openURL() method of React Native.

Linking.openURL(url).catch(err =>
      console.error("Couldn't load page", err),
    );

The user will see a "Continue Screen" and will not need to enter their credentials again to log in.