Accessing markdown files with Vercel and Remix.run

Question

I'd like to know if it's possible to deploy a Remix.run project on Vercel that accesses markdown files. A project just like the blog tutorial;

// posts.js
const postsPath = path.join(__dirname, "..", "posts");

The warning says: "If you did not use the Remix App Server you'll probably need to add an extra ".." on the path. Also note that you can't deploy this demo anywhere that doesn't have a persistent file system.".

I tried with an extra "..". I thought Vecel could have a permanent file system with "ENABLE_FILE_SYSTEM_API": "1" but it's apparently not the case. Or is it?

Here is the Remix config:

module.exports = {
  appDirectory: 'app',
  assetsBuildDirectory: 'public/build',
  publicPath: '/build/',
  serverBuildDirectory: 'api/_build',
  ignoredRouteFiles: ['.*'],
  // mdx,
}