description: Zero-dependency schema validation library with strict-by-default objects, async refinements, coercion, flexible schema composition, and full TypeScript inference. package: validit category: validation keywords: [schema, validation, type-safe, parsing, runtime-validation, zod-like, coercion] related: [formit, fetchit, deposit] exports: [v, toJsonSchema, ValidationError, configure]

@vielzeug/validit

Zero-dependency schema validation library with strict-by-default objects, async refinements, coercion, flexible schema composition, and full TypeScript inference.

Package: @vielzeug/validit  ·  Category: Validation

Key exports: v, toJsonSchema, ValidationError, configure

When to use: Zero-dependency schema validation library with strict-by-default objects, async refinements, coercion, flexible schema composition, and full TypeScript inference.

Related: @vielzeug/formit · @vielzeug/fetchit · @vielzeug/deposit

@vielzeug/validit is part of Vielzeug and ships as a zero-dependency TypeScript package with ESM+CJS output.

Installation

pnpm add @vielzeug/validit
npm install @vielzeug/validit
yarn add @vielzeug/validit

Quick Start

import { flattenFirstErrors, v, type Infer } from '@vielzeug/validit';

const UserSchema = v.object({
  id: v.coerce.number().int().positive(),
  name: v.string().trim().min(1),
  email: v.string().trim().email(),
  role: v.union('admin', 'editor', 'viewer').default('viewer'),
  tags: v.array(v.string()).unique().default([]),
});

type User = Infer<typeof UserSchema>;

const result = UserSchema.safeParse({ id: '42', name: 'Ada', email: '[email protected]' });

if (result.success) {
  const user: User = result.data;
  console.log(user.id); // 42
} else {
  console.log(flattenFirstErrors(result.error));
}

Documentation

• Overview
• Usage Guide
• API Reference
• Examples

License

MIT © Helmuth Saatkamp — part of the Vielzeug monorepo.