Access request headers from events callbacks

[michaelhays]

We use the signIn() callback to record audit logs, and need to access the request headers to record relevant fields like the user's IP address.

Is this possible in NextAuth.js? I'm using version 5.0.0-beta.3.

[Wundero]

If you are using the app router, I believe you can get headers using the headers() function from next/headers. Besides that, there doesn't appear to be a way to access the headers from that callback.

Below is the reference in the code:

OAuth signIn callback found here.
If you are willing to delve into your node_modules and use something like patch-package, you could make the changes necessary yourself (the function that calls the callbacks does have access to headers), but this might be a bit tricky.

I think it could be a good addition to the library, since having access to headers (and cookies, for that matter) in the callbacks might make certain tasks easier.

[michaelhays]

Wow, headers() worked perfectly 🎉

I didn't even bother trying that before because I thought it would've been outside of that context, hah. Thanks so much!

[YHADJRABIA]

Found a simpler way with cookies() of next/headers

      const cookies = cookies()
      const locale = cookies?.get('NEXT_LOCALE')?.value

It gives me access to the locale with the signIn callback

[heijmerikx]

Yeah, great! Just what I was looking for as well. I didn't thought about this solution too. I tried wrapping the NextAuth config in a request, which did seem to work, but got a TypeError: r is not a function on deployment. This works like charm! A year later on Next.js v14 using auth.js beta.