[中文] | [English]

Valype 🐉

TypeScript Runtime Validator - Generate validation from type definitions

Warning

Valype is currently under active development. APIs may change in future releases. Please follow Semver to avoid breaking changes.

• 🎯 Type-safe validation with TypeScript type inference
• 🔌 Seamless unplugin integration (Vite/Rollup/esbuild/Astro/Farm/Nuxt/Rspack/Webpack)
• 🛡️ Unified type validation
• 🚧 TypeScript plugin (WIP)
• 🚧 IDE/editor extension support (WIP)

Valype = Validate + Type. Automatically generates runtime validators from TypeScript type definitions.

🚀 Getting Started

1. Install plugin:

# for npm users
npm add zod@latest
npm add -D unplugin-valype

# for yarn users
yarn add zod@latest
yarn add -D unplugin-valype

# for pnp users
pnpm add zod@latest
pnpm add -D unplugin-valype

# for bun users
bun add zod@latest
bun add -D unplugin-valype

zod's version should be 3.25.0 at least, because valype generates zod v4 schema

2. Configure plugin for your build tool following unplugin-valype docs

3. Define your types (use .valype.ts extension):

// user.valype.ts
export interface User {
  name: string
  age: number
}

4. Use the generated validator:

import { validateUser } from './user.valype'

const issues = validateUser(data) // Returns ZodIssue[] or undefined
if (issues) {
  // Handle validation errors
}

📖 Usage

unplugin-valype generates validators for types exported from *.valype.ts files. The validator type signature is:

export declare function validateSome(data: unknown): ZodIssue[] | undefined

• Returns undefined when validation passes
• Returns ZodIssue[] with error details when validation fails

Note

You typically don't need to use valype package directly, just use the generated validators.

📦 Packages

Package	Version	Description
valype		Core schema generation logic
unplugin-valype		Build tool plugin

💡 Motivation

While TypeScript ensures compile-time type safety, runtime data validation remains essential. Traditional solutions like Zod require duplicate type definitions and lose valuable tsdoc information. Valype solves this by:

• Single Source of Truth - Define types once, get both static and runtime validation
• Full Type Information - Preserves all tsdoc documentation and editor hints
• Seamless Integration - Works natively with TypeScript tooling

const userSchema = z.object({
  name: z.string(),
  age: z.number(),
})

type User = z.infer<typeof userSchema>
// And `User['name'] does not have tsdoc info

Using valype:

export interface User {
  /**
   * name of user
   */
  name: string
  age: number
}

// Validator is generated automatically!
const result = validateUser(data)

// Also `User['name'] has tsdoc info

Valype lets you define types once and get runtime validation automatically!

🥰 Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

🪪 License

MIT

🙏 Inspired By

Valype draws inspiration from these excellent projects:

• ts-to-zod
• Zod
• @sinclair/typebox

🌟 Star History