@vlandoss/envv0.5.0

contract-first environment configuration

Your env, declared
once and validated
before user code runs.

Describe every variable in a single Standard Schema contract — Zod, Valibot, ArkType. Resolve it against per-environment config files and your environment variables at boot. Missing or malformed values fail the process before user code ever reads them.

Read the docs

runtime-agnostic ·NodeBunDenoBrowsersWorkersEdge

import { schema, type Config } from "@vlandoss/env";
import * as z from "zod";

export const Env = schema({
  server: {
    HOST: z.string(),
    PORT: z.coerce.number().int().positive()
  },
  db: {
    URL: z.string()
  },
});

export type EnvConfig = Config<typeof Env>;

import { defineEnv } from "@vlandoss/env";
import { loadConfig } from "@vlandoss/env/fs";
import { Env } from "./schema.ts";

const config = loadConfig(Env);

export const env = defineEnv({
  schema: Env,
  config,
});

●contract validated · 2 branches · 3 leaves

●wiring resolved · process.env merged · typed env emitted

env.server.PORT→number

The problem with reading env vars directly.

process.env is a string-map of unknowns. The first time you find out a value is missing is when something else crashes downstream.

before

.env files duplicated per environment, secrets and defaults tangled.

→

after

A versioned config file per environment. Secrets stay in your env vars.

before

process.env.PORT is a string. process.env.MISSING is undefined. Silent.

→

after

env.server.PORT is number. Missing values throw at boot, with the dot-path.

before

Locked to one validator. Locked to one runtime. Locked to one bundler.

→

after

Standard Schema in. Any runtime out. Opt-in adapters for Node, Vite, React.

Five entrypoints. Import only what you run.

The core stays portable. Filesystem, bundlers, and browser hydration live in opt-in adapters with their own peer dependencies.

Any

core

@vlandoss/env

Declare a schema. Resolve a typed env at boot.

import from"@vlandoss/env"

Node / Bun / Deno

@vlandoss/env/fs

Discover & load per-environment config files from disk.

import from"@vlandoss/env/fs"

Build time

plugin

@vlandoss/env/vite

Vite plugin: alias #config, inject envName into the bundle.

import from"@vlandoss/env/vite"

SSR / SSG

react

@vlandoss/env/react

<EnvScript /> ships the server-resolved env to the browser.

import from"@vlandoss/env/react"

Any

zod

@vlandoss/env/zod

Opinionated Zod primitives: port, host, bool, secret…

import from"@vlandoss/env/zod"

works with any Standard Schema validator

ZodValibotArkTypeStandard Schema

No mapping ceremony. Just dot-path → SCREAMING_SNAKE.

camelCase keys are converted automatically. Override the rare exception with a one-line entry in vars.

schema path	env var
`server.PORT`	→`SERVER_PORT`
`db.URL`	→`DB_URL`
`sessionCookie.PREFIX`	→`SESSION_COOKIE_PREFIX`
`db.kit.LOGGING`	→`DB_KIT_LOGGING`
`PORT`	→`PORT`

override

defineEnv({
  schema: Env,
  vars: {
    db: { URL: "DATABASE_URL" },
    public: {
      $: null,                   // flat branch
      APP_NAME: "PUBLIC_APP_NAME"
    },
  },
});

One schema for every environment,
validated at boot.

Read the docs View on GitHub

MIT licensed·made atVariable Land·v0.5.0·2026

Your env, declared once and validated before user code runs.

The problem with reading env vars directly.

Five entrypoints. Import only what you run.

No mapping ceremony. Just dot-path → SCREAMING_SNAKE.

One schema for every environment,validated at boot.

Your env, declared
once and validated
before user code runs.

One schema for every environment,
validated at boot.