Session null after calling signIn from a server action with redirect false

[dev2xl]

Description

I'm attempting to retrieve the user session immediately after calling signIn with redirect: false inside a Next.js server action. The goal is to dynamically calculate the redirect URL based on the user's role. However, when I call auth() right after signIn, it returns null.

Expected Behavior

After calling signIn with redirect: false, I should be able to retrieve the user session immediately using auth() to determine the user's role and calculate the redirect URL.

Actual Behavior

When calling auth() immediately after signIn, it returns null, making it impossible to calculate the redirect URL based on user data.

Steps to Reproduce

1. Call signIn with redirect: false in a Next.js server action.
2. Call auth() right after signIn to retrieve the session.
3. Observe that auth() returns null.

Current Workaround

• Use a temporary route for signIn.
• Employ middleware to redirect based on the user's role.

Problems with this workaround:

• The URL in the browser's address bar does not update correctly.
• The approach feels hacky and less maintainable.

Question

What is the best way to dynamically calculate the redirect URL based on user data after signIn without encountering the above issues?

Environment

• Framework: Next.js
• AuthJS: 5 beta 25
• Node Version: 18