@kasoa/env

Type-safe environment variable validation using Standard Schema.

Installation

``bash
pnpm add @kasoa/env valibot
`

Usage

`ts
import { defineEnv } from "@kasoa/env";
import * as v from "valibot";

const env = defineEnv(
v.object({
DATABASE_URL: v.pipe(v.string(), v.url()),
PORT: v.pipe(v.string(), v.transform(Number)),
NODE_ENV: v.optional(
v.picklist(["development", "production"]),
"development",
),
}),
);

// env is fully typed:
// { DATABASE_URL: string; PORT: number; NODE_ENV: "development" | "production" }
`

Features

- Works with any Standard Schema compatible library (Valibot, Zod, ArkType, etc.)
- Treats empty strings as missing values
- Throws with formatted error messages listing all invalid variables
- Full TypeScript inference

API

$3

Validates environment variables against the provided schema.

- schema - A Standard Schema compatible schema
- env - Optional env object (defaults to process.env)

Returns the validated and typed environment object.

Throws an Error if validation fails:

`
Environment validation failed:

DATABASE_URL: Invalid URL
PORT: Required
`

$3

Type helper to infer the output type of a schema:

`ts
import type { InferEnv } from "@kasoa/env";

const schema = v.object({ PORT: v.string() });
type Env = InferEnv;
// { PORT: string }
``