What have you done? What did you try?

export default withAuth(
  function middleware(request: NextRequestWithAuth) {
    if (
      request.nextUrl.pathname.startsWith("/admin") &&
      request.nextauth.token?.role !== "admin"
    ) {
      return NextResponse.redirect(new URL("/denied", request.url));
    } else if (
      request.nextUrl.pathname.startsWith("/admin") &&
      request.nextauth.token?.role === "admin"
    ) {
      return NextResponse.next();
    } else {
      return NextResponse.redirect(new URL("/denied", request.url));
    }
  },
  {
    callbacks: {
      authorized: ({ token }) => !!token,
    },
  }
);

export const config = {
  matcher: "/admin/:path*",
};

export const authOptions = {
  providers: [
    CredentialsProvider({
      name: "credentials",
      credentials: {},

      async authorize(credentials: any): Promise<any> {
        const { email, password } = credentials;

        try {
          await connectToDB();
          const user = await User.findOne({ email });

          if (!user) {
            return null;
          }

          const passwordsMatch = await bcrypt.compare(password, user.password);

          if (!passwordsMatch) {
            return null;
          }

          return user;
        } catch (error) {
          console.log("Error: ", error);
        }
      },
    }),
  ],
  session: {
    strategy: "jwt",
  },
  secret: process.env.NEXTAUTH_SECRET,
  pages: {
    signIn: "/",
  },
  callbacks: {
    jwt({ token, user }: any) {
      if (user) {
        return { ...token, id: user.id, role: user.role }; // Add role property
      }
      return token;
    },
    session: ({ session, token }: any) => {
      return {
        ...session,
        user: {
          ...session.user,
          id: token.id,
          role: token.role,
        },
      };
    },
  },
};

i tried doing it with a server action it works but it will run every time the app is running which is not practical

I want to find out the best way to do this without messing up the app perf

I understand

I mean, reading your code, it's doing what you want it to do anyway

However to simple make it perorm well,

Here’s one approach using a server-side setup function. You can create a function to check if an admin user exists and create one if not, and call this function when the server starts.

Steps:
Create a setup function:
This function will check if an admin user exists in the database. If not, it will create one.

Call the setup function on server startup:
Depending on your setup, you might call this function in a custom server script or within a Next.js API route.

I was looking to do that but was not too sure if it was the right thing to do

Should i call this function in the middleware

As long as it solved the problem, sure

Thanks