rallly/packages/utils/src/absolute-url.ts

const port = process.env.PORT || 3000;

const getVercelUrl = () => {
  return process.env.NEXT_PUBLIC_VERCEL_URL
    ? `https://${process.env.NEXT_PUBLIC_VERCEL_URL}`
    : null;
};

export function absoluteUrl(path = "") {
  const baseUrl =
    process.env.NEXT_PUBLIC_BASE_URL ??
    getVercelUrl() ??
    `http://localhost:${port}`;
  return `${baseUrl}${path}`;
}