Load .env file

[SimoMay]

Hi,

I see you using c12 and dotenv (installed but never used in code as far as I can see) but I can't get the .env file to load in config, the only way that work is to add an extends with a ts file

What ways I can load .env file into Nitro?

[harshagarwalnyu]

Nitro loads .env automatically in development via dotenv. In production, .env files are intentionally not loaded — environment variables are expected to come from your deployment environment (the host's env vars, not a file).

The recommended pattern:

1. Define your variables in nitro.config.ts (or nuxt.config.ts for Nuxt):

// nitro.config.ts
export default defineNitroConfig({
  runtimeConfig: {
    mySecret: '',          // private, server-only
    public: {
      apiBase: '/api',     // accessible client-side too (Nuxt)
    },
  },
});

2. Set them in your .env file for local development:

NITRO_MY_SECRET=super-secret-value

3. Access them in handlers:

const config = useRuntimeConfig();
console.log(config.mySecret); // the value from env

The key is the naming convention: NITRO_ prefix maps to Nitro's private runtimeConfig, and NUXT_PUBLIC_ maps to public config in Nuxt. Nitro uses c12 for config resolution which handles the .env loading in dev via dotenv under the hood, but only when NODE_ENV !== 'production'.

If you specifically need to load a .env file in production (e.g., for local Docker deployments), you can call dotenv.config() at the top of your server entry, but the conventional approach is to set env vars in your deployment platform.