src/routes/r/[id]/+page.server.ts

import type { PageServerLoad } from './$types';
import { collections } from '$lib/server/database';
import { error } from '@sveltejs/kit';

export const load: PageServerLoad = async ({ params }) => {
	const conversation = await collections.sharedConversations.findOne({
		_id: params.id
	});

	if (!conversation) {
		throw error(404, 'Conversation not found');
	}

	return {
		messages: conversation.messages
	};
};