Integrate Custom App Experiences with the Salesforce UI

Give users uninterrupted access across custom apps and Salesforce. With the new Single-Access UI Bridge API, use an existing Salesforce access token to load a new session in a Salesforce UI, such as a Visualforce site or mobile app. For example, when users are logged in to a headless app, redirect them to your Experience Cloud site to view Support cases without making them log in again.

Where: This change applies to Lightning Experience and Salesforce Classic in all editions.

How: Using a POST request, send an access token to the new /services/oauth2/singleaccess endpoint on your My Domain or Experience Cloud site. Salesforce returns a JSON response with a frontdoor.jsp URL. Use the URL to redirect the user and load a new, authenticated session in a custom interface.

https://help.salesforce.com/s/articleView?id=release-notes.rn_security_frontdoor_url.htm&release=250&type=5