# @vite-env/core

> The env.ts layer for Vite. You define your variables once, validate them everywhere, and import them with types.

This plugin does for Vite what `@t3-oss/env` does for Next.js. It is built natively on Vite 8 and Rolldown. You define your environment variables once with a schema. You then get validated, typed imports everywhere.

## Why I Built This

I wrote about four problems with plain Vite environment variables: no validation, no type safety, string-only values, and easy server-client leaks. See [the four problems with plain Vite environment variables](/writings/why-i-built-a-new-vite-env-plugin). This plugin solves all four problems.

## Key Features

- Typed virtual modules: You import `env` with full IntelliSense.
- Server/client split: The plugin detects leaks at build time.
- Zod v4 native validation: The plugin also supports Standard Schema, including Valibot and ArkType.
- Auto `.d.ts` generation: You get type safety without manual declarations.
- Platform presets: The plugin supports Vercel, Railway, and Netlify.
- HMR `.env` watching: Changes reload without a restart.

## Technical Details

The plugin generates virtual modules at build time. It splits server and client variables into separate imports. If client code imports a server variable by accident, the build fails. This stops secret leaks before they happen.

## Getting started

1. Install `@vite-env/core` and add the plugin to your Vite config.
2. Create an `env.ts` file with your schema.
3. Import from `virtual:env/client` or `virtual:env/server`.
4. Type-check your environment variables at build time.

## Why it matters

Environment variable bugs are silent and dangerous. A missing key returns `undefined`. A leaked secret exposes your backend. This plugin makes environment variables type-safe and validated. It catches errors at build time instead of runtime.