Validator mode

ArkEnv supports two validator modes that control how environment variables are parsed and validated.
You select the mode via the validator option in the arkenv configuration.

Cheatsheet - when to use which?

In a new project, prefer the default arktype mode. standard exists for migrations and ArkType-free setups.

validator: "arktype" (default)

ArkEnv runs validation through ArkType and expects it to be installed.

What you get

• Native support for ArkType's string-based DSL ("string.url", "number > 0", etc.)
• Built-in, intuitive coercion from strings
• Full Standard Schema support (Zod, Valibot, etc.)

import arkenv from 'arkenv';
import { type } from 'arkenv/arktype';
import { z } from 'zod';

const env = arkenv({
  PORT: "number.port",
  NODE_ENV: type("'development' | 'production'"),
  DATABASE_URL: z.string().url(),
});

Requirements

You must install arktype alongside arkenv.

validator: "standard"

In Standard mode, ArkEnv works directly with any validator that implements the Standard Schema interface, without ArkType.

When this makes sense

• You already use Zod or Valibot everywhere
• You want a zero-ArkType runtime
• You care more about minimal dependencies than DSL ergonomics

Tradeoffs

• No native ArkType DSL strings ("number.port", "string.host")
• No ArkType coercion - use your validator's native coercion instead

import arkenv from 'arkenv';
import { z } from 'zod';

const env = arkenv(
  {
    PORT: z.coerce.number().int().min(0).max(65535),
    DATABASE_URL: z.string().url(),
  },
  { validator: "standard" }
);

Requirements

A validator that implements Standard Schema (e.g. zod@^3.24.0, valibot@^1.0.0).