.env variables are undefined (not accessible) in api routes after project deployed to vercel

[mtin79]

hi there,
i hope there might be someone who knows next.js deployment architecture well enough to be able to help me with an issue that i can't find a solution for.

i manage deployment variables in .env file like this:

VARIABLE_NAME=....
OTHER_NAME=....
NEXT_PUBLIC_NAME=...

i need to access VARIABLE_NAME 's value in api routes (functions).
everything works when i run "npm run dev" or "npm run build + npm run start".
but as soon as i deploy the project to vercel via "vercel" or "vercel prod" the value of the VARIABLE_NAME is undefined or empty or not there. strangely enough is that the NEXT_PUBLIC_NAME 's value can be used inside the api routes functions.

if i create a new project with next and do the same thing the .env mechanism works also when i deploy to vercel.

any help is much appreciated!

[rowin1125]

I have the same issue atm. Did you solve the issue already?

[jensmeindertsma]

I think this goes beyond my knowledge from this point. I'd suggest talking to Vercel's support team.

[rowin1125]

Rebuilding from scratch and redoploying piece by piece to debug, thanks for your support anyway :D

[lallenfrancisl]

How this could be solved is by defining it in nextjs.config.js, not sure why I was also searching for it.

module.exports = {
  future: {
    webpack5: true,
  },
  async redirects() {
    return [
      {
        source: '/',
        destination: '/login',
        permanent: true,
      },
    ];
  },
  env: {
    NEXT_PUBLIC_API_URI: process.env.NEXT_PUBLIC_API_URI,
    NEXT_PUBLIC_CLIENT_ID: process.env.NEXT_PUBLIC_CLIENT_ID,
    NEXT_PUBLIC_CLIENT_SECRET: process.NEXT_PUBLIC_CLIENT_SECRET,
  },
};

The NEXT_PUBLIC_ is also not needed when doing this

[teemo-dunamu]

to solve, check .env files in your deployed server project root. if not, you should copy .env files.

[MefitHp]

I got here after 2 days of debugging a Keystone/Next js app an this env what the issue. Thank you so much for your help @lallenfrancisl