need help! session.guilds is not persisting.

[Tizooo]

What im trying to do & the issue:
Hey! im currently trying to make a Dashboard for my Discord Bot. For authentication purposes i need to verify that the user has has access to specific guilds. For that i use session.guilds to save the guilds in there which the user should have access to. The problem i have is that if i try to get the session.guilds again the value i put in there is gone.

Code reference:

Here i define my authOptions

// app/api/auth/[...nextauth]/route.js
import NextAuth from 'next-auth';
import DiscordProvider from 'next-auth/providers/discord';

export const authOptions = {
  providers: [
    DiscordProvider({
      clientId: process.env.DISCORD_CLIENT_ID,
      clientSecret: process.env.DISCORD_CLIENT_SECRET,
      authorization: {
        params: {
          scope: 'identify guilds', // Scopes you want to request
        },
      },
    }),
  ],
  secret: process.env.NEXTAUTH_SECRET,
  callbacks: {
    async jwt({ token, account }) {
      // Save access token
      if (account) {
        token.accessToken = account.access_token;
        token.guilds = user?.guilds || [];
      }
      return token;
    },
    async session({ session, token }) {
      // Attach access token to session
      session.accessToken = token.accessToken;
      session.guilds = token.guilds || [];
      return session;
    },
  },
};

const handler = NextAuth(authOptions);

export { handler as GET, handler as POST };

Here i get the guilds a user should have access to and add them to the session using session.guilds = mutualGuilds;.

// app/api/getGuilds/route.js
import { NextResponse } from 'next/server';
import { getServerSession } from "next-auth";
import { authOptions } from '../auth/[...nextauth]/route';

export async function GET(req) {
  console.log('Fetching guilds...');
    const accessToken = req.headers.get('Authorization');

    if (!accessToken) {
      console.error('Authorization token not provided.');
      return NextResponse.json({ error: 'Authorization token is required' }, { status: 401 });
    }

  try {
    // Get user guilds
    const userResponse = await fetch('https://discord.com/api/users/@me/guilds', {
      headers: {
        Authorization: accessToken,
      },
    });

    if (!userResponse.ok) {
      console.error('Failed to fetch user guilds:', userResponse.statusText);
      return NextResponse.json({ error: 'Failed to fetch user guilds' }, { status: userResponse.status });
    }
    
    const userGuilds = await userResponse.json();

    // Filter user guilds where user has administrator permissions
    const adminGuilds = userGuilds.filter((guild) => {
      return (guild.permissions & 0x8) === 0x8; // Check if the administrator permission is set
    });

    // Get bot guilds
    const botResponse = await fetch('https://discord.com/api/v9/users/@me/guilds', {
      headers: {
        Authorization: `Bot ${process.env.DISCORD_BOT_TOKEN}`,
      },
    });

    if (!botResponse.ok) {
      console.error('Failed to fetch bot guilds:', botResponse.statusText);
      return NextResponse.json({ error: 'Failed to fetch bot guilds' }, { status: botResponse.status });
    }

    const botGuilds = await botResponse.json();

    // Find guilds where both the user is an admin and the bot is in the guild
    const mutualGuilds = adminGuilds.filter(userGuild =>
      botGuilds.some(botGuild => botGuild.id === userGuild.id)
    );


    const session = await getServerSession(authOptions);
    session.guilds = mutualGuilds;
    console.log(session);


    return NextResponse.json(mutualGuilds);
} catch (error) {
  console.error('An error occurred while fetching guilds:', error);

  return NextResponse.json({ error: 'Failed to retrieve guilds.' }, { status: 500 });
  }
}

The console.log outputs the following (some values changed for privacy):

{
  user: {
    name: 'tizooo',
    email: '[email protected]',
    image: 'https://cdn.discordapp.com/avatars/310844659421707264/d1b7741252a98473c80a5ce0272274bf.png'
  },
  accessToken: 'G2YyFisL8pamFF6MmBf9IISrXS6snq',
  guilds: [
    {
      id: '1244951898239275061',
      name: 'Leveling',
      icon: 'eb9e133aea8aa28b1aac89de655b158f',
      banner: null,
      owner: true,
      permissions: 2147483647,
      permissions_new: '2251799813685247',
      features: [Array]
    }
  ]
}

and then i try to read the value so i can verify that the user has access to this guild. but here the console.log output shows [] so it somehow did not take over the values ive set...

// app/dashboard/[id]/page.js

import { getServerSession } from "next-auth";
import { authOptions } from '../../api/auth/[...nextauth]/route';
import { redirect } from 'next/navigation';

export default async function GuildPage({ params }) { // the authorized id is id: 1244951898239275061
    const { id } = params; // returns 1244951898239275061

    const session = await getServerSession(authOptions);
    console.log('User Guilds:', JSON.stringify(session.guilds, null, 2));

    const isAuthorized = session.guilds.some(guild => guild.id === id);


    if (!isAuthorized) {
      redirect('/dashboard');
    }
  
    return (
      <div>
        <h1>Guild ID: {id}</h1>
      </div>
    );
  }