Next.js 13.4 and NextAuth Type Error: 'AuthOptions' is not assignable to type 'never'

Issue

I'm currently working on a Next.js 13.4 project and trying to set up NextAuth using the app/ router. However, I'm encountering a type error that I can't seem to resolve.

Here's my route.ts file:

import NextAuth, { AuthOptions } from "next-auth";
import DiscordProvider from "next-auth/providers/discord";

export const authOptions: AuthOptions = {
  providers: [
    DiscordProvider({
      clientId: process.env.CLIENT_ID as string,
      clientSecret: process.env.CLIENT_SECRET as string,
    }),
  ],
  session: {
    strategy: "jwt",
  },
  secret: process.env.NEXTAUTH_SECRET,
}

const handler = NextAuth(authOptions);

export { handler as GET, handler as POST }

And here's the error message when running 'npm run build':

- info Linting and checking validity of types ...Failed to compile.

.next/types/app/api/auth/[...nextauth]/route.ts:8:13
Type error: Type 'OmitWithTag<typeof import("C:/Users/Luk/Documents/Workspace/zerotwo-dash/src/app/api/auth/[...nextauth]/route"), "GET" | "POST" | "HEAD" | "OPTIONS" | "PUT" | "DELETE" | "PATCH" | "config" | ... 6 more ... | "runtime", "">' does not satisfy the constraint '{ [x: string]: never; }'.
  Property 'authOptions' is incompatible with index signature.
    Type 'AuthOptions' is not assignable to type 'never'.

   6 |
   7 | // Check that the entry is a valid entry
>  8 | checkFields<Diff<{
     |             ^
   9 |   GET?: Function
  10 |   HEAD?: Function
  11 |   OPTIONS?: Function

I really have no idea whats happening here... when looking up the 'AuthOptions' on t he github page from nextauth i see nothing wrong with my code..

I would appreciate any insights or suggestions on how to resolve this issue. Thanks in advance!

Solution

Basically the issue is with exporting the authOptions with handlers in the route.ts file for nextJs 13.4+, just by removing the export from the authOptions you will be good to go. That was the reason seperating the authOptions worked :).

route.ts -->

import NextAuth, { AuthOptions } from "next-auth";
import DiscordProvider from "next-auth/providers/discord";

// Here we removed the export
const authOptions: AuthOptions = {
  providers: [
    DiscordProvider({
      clientId: process.env.CLIENT_ID as string,
      clientSecret: process.env.CLIENT_SECRET as string,
    }),
  ],
  session: {
    strategy: "jwt",
  },`enter code here`
  secret: process.env.NEXTAUTH_SECRET,
}

const handler = NextAuth(authOptions);

export { handler as GET, handler as POST }

In case we want the authOptions somewhere else we can do that like --->

import NextAuth, { AuthOptions } from "next-auth";
import DiscordProvider from "next-auth/providers/discord";

// Here we removed the export
const authOptions: AuthOptions = {
  providers: [
    DiscordProvider({
      clientId: process.env.CLIENT_ID as string,
      clientSecret: process.env.CLIENT_SECRET as string,
    }),
  ],
  session: {
    strategy: "jwt",
  },`enter code here`
  secret: process.env.NEXTAUTH_SECRET,
}

const handler = NextAuth(authOptions);

export { handler as GET, handler as POST, authOptions }

Answered By - tumun shaily