• ✅ Load environment variables from the command line API_BASE=/v1/ core
• ✅ Load environment variables from .env files
• ✅ Expand environment variables API_URL=$API_BASE/users
• ✅ Define environment variables for a specific environment (e.g. .env.production)
• ✅ Load priorities of .env.* files (e.g. .env.production > .env)
• ✅ Hierarchical cascading configuration in monorepo projects (Nx, Turbo, etc.) apps/next-app/.env > apps/.env > .env

npm add @dotenv-run/core

// index.js
import { env } from "@dotenv-run/core";
env({
  root: "../..",
  verbose: true,
  prefix: "^API_",
  files: [".env"],
});
console.log(process.env.API_USERS);

given the following files:

.env
    API_USERS=$API_BASE/v1/users
    API_AUTH=$API_BASE/v1/auth
.env.dev
    API_BASE=https://localhost:3000
.env.prod
    API_BASE=https://dotenv-run.app

then:

NODE_ENV=dev node index.js
https://localhost:3000/v1/users

NODE_ENV=prod node index.js
https://dotenv-run.app/v1/users

MIT © Chihab Otmani