Installation

> [!NOTE]
>
> This is an ESM only package that requires a tsconfig with a module resolution that can read package.json#exports (NodeNext if transpiling with tsc, Bundler if using a bundler).

``bash


Core package, no framework specific features

bun add envin

CLI, used e.g. for live previews

bun add @envin/cli
`

For full documentation, see https://envin.turbostarter.dev

Usage

> [!NOTE]
>
> You may use any Standard Schema compliant validator of your choice.

This package supports the full power of most popular schema libraries, meaning you can use transforms and default values.

$3

`ts
// env.config.ts
import { defineEnv } from "envin";
import * as z from "zod";

export default defineEnv({
/*
* Shared environment variables, available on the client and server.
*/
shared: {
NODE_ENV: z.enum(["development", "production"]).default("development"),
},
/*
* Prefix for client environment variables.
*/
clientPrefix: "NEXT_PUBLIC_",
/*
* Environment variables available on the client (and server).
*
* 💡 You'll get type errors if these are not prefixed with NEXT_PUBLIC_.
*/
client: {
NEXT_PUBLIC_API_URL: z.url(),
},
/*
* Serverside Environment variables, not available on the client.
* Will throw if you access these variables on the client.
*/
server: {
DATABASE_URL: z.url(),
},
/*
* In some cases, we need to manually destructure environment variables to make sure all are included in bundle.
*
* 💡 You'll get type errors if not all variables are included here.
*/
envStrict: {
DATABASE_URL: process.env.DATABASE_URL,
NEXT_PUBLIC_API_URL: process.env.NEXT_PUBLIC_API_URL,
},
});
`

$3

`ts
// route.ts
import env from "~/env.config";

export const GET = (req: Request) => {
const DATABASE_URL = env.DATABASE_URL;
// use it...
};
`

Live Preview

One of the most powerful features of this package is the ability to preview your environment variables in a livemode.

`bash


Run the CLI with your env.config.ts file


npx @envin/cli@latest dev
`

!Live Preview

This will start a live preview server that will automatically update your environment variables when you change them allowing you to find and fix errors before deploying your app.

$3

`bash
npx @envin/cli@latest dev [options]
`

Options:
- -c, --config : explicit path to env.config.ts
- -e, --env : path(s) to .env file(s) or directories
- -p, --port : port to run the preview server (default: 3000)
- -v, --verbose: enable verbose logging

#### Env loading behavior

The CLI uses the following precedence within each directory:
- .env → .env.local → .env.development → .env.development.local
- .env → .env.local → .env.production → .env.production.local

If -e points to a single file, only that file is used. If -e points to a directory, only that directory is used. If multiple paths are provided, they must all be files or all be directories. Without -e`, the CLI uses the current working directory.

Contributing

See CONTRIBUTING.md.