Basically typed-env, but with support for choices and maintained.

A typed environment variable parser with support for choices, custom parsers, and more.

Node.js ^14.18.0, v16 or newer is required. See issue #1.

npm i neon-env

import { createEnv } from 'neon-env';

const env = createEnv({
  PORT: { type: 'number', default: 80 }
});

env.PORT; // number

• Strongly typed
• Supports custom parsers
• Supports optional environment variables
• Supports limiting the possible values (see Choices)
• Supports passing custom environments (see Options)

import { createEnv } from 'neon-env';

const env = createEnv({
  NODE_ENV: {
    type: 'string',
    choices: ['development', 'production']
  }
});

env.NODE_ENV; // 'development' | 'production'

As of 0.2.0, you no longer need to add as const to the choices array to get the best type safety.

You can pass a parser function to return your own custom type

import { createEnv } from 'neon-env';

const env = createEnv({
  HOMEPAGE: { parser: url => new URL(url) }
});

env.HOMEPAGE; // URL

If you want to use a custom env, pass env in the options parameter, otherwise it will load from process.env

interface Options {
  env?: Record<string, string> | NodeJS.ProcessEnv;
}