postcast-tool/app/api/billing/plans/route.js

import { NextResponse } from 'next/server';

const ENGINE_URL    = process.env.ENGINE_URL    || 'http://localhost:3030';
const ENGINE_SECRET = process.env.ENGINE_SECRET || '';

export async function GET() {
  try {
    const res = await fetch(`${ENGINE_URL}/api/billing/plans`, {
      headers: { 'x-internal-secret': ENGINE_SECRET },
      cache: 'no-store',
    });
    const data = await res.json();
    return NextResponse.json(data);
  } catch (err) {
    return NextResponse.json({ error: err.message }, { status: 500 });
  }
}