validex

Type-safe validation rules built on Zod — tree-shakeable, so you only ship what you use. The main package is @validex/core with optional adapters @validex/nuxt and @validex/fastify.

Install
Quick Start
Why validex?
Rules — all 25 rules at a glance
Bundle Size
Configuration — global defaults, three-tier merge, preloading
Cross-Field Validation — sameAs, requiredWhen
Chainable Methods — checks and transforms on any Zod string
Check Functions — standalone pure functions
Error Handling — structured errors, getParams, validate()
i18n — translations, CLI, 141 error codes
Custom Rules — createRule, customFn, custom regex
Framework Adapters — Nuxt, Fastify
Documentation

Install

pnpm add @validex/core zod   # core is required
pnpm add @validex/nuxt       # optional — Nuxt adapter
pnpm add @validex/fastify    # optional — Fastify adapter

Quick Start

Single rule

import { Email } from '@validex/core'

const schema = Email()
schema.parse('hello@example.com') // OK
schema.parse('not-an-email')      // throws ZodError

Rule with options

import { Password } from '@validex/core'

const schema = Password({
  length: { min: 10 },
  uppercase: { min: 2 },
  blockCommon: 'basic',
})

schema.parse('ABcdefgh1!') // OK — 10+ chars, 2 uppercase, 1 digit, 1 special

Composed schema with `validate()`

import { z } from 'zod'
import { Email, Password, validate } from '@validex/core'

const schema = z.object({
  email: Email(),
  password: Password(),
})

const result = await validate(schema, {
  email: 'user@example.com',
  password: 'Str0ng!Pass',
})

if (result.success) {
  console.log(result.data) // typed as { email: string; password: string }
} else {
  console.log(result.errors)      // { email: ['...'], password: ['...'] }
  console.log(result.firstErrors) // { email: '...', password: '...' }
}

Why validex?

I built validex because I was fed up writing the same validation rules over and over again in every project.

Different teams, different defaults, forgetting what I had configured last time, and ending up with inconsistent behavior across the codebase. Sound familiar?

Validex was created to solve that pain once and for all:

One config system — setup() lets you define your defaults globally, per-rule, or per-call. Three-tier merge (built-in defaults → global config → per-call options) so you never repeat yourself again.
One consistent error surface — validate() always returns the same clean shape — flat errors, nested errors, first-per-field, raw issues. One function, one result, every time.
Every error is validex-owned — no raw Zod messages leak to your users. Every error carries a namespace, code, and label for precise routing.
25 production-ready rules covering the fields you actually use: identity, auth, networking, finance, and text.
Tree-shakeable & lightweight — 5–6 kB Brotli per rule (shared core included). All 25 rules together = 13 kB. Heavy data loads on demand.
i18n-ready out of the box — key mode, t() function support, label/message transforms, and a CLI that generates ready-to-translate locale files.
First-class framework adapters — Nuxt and Fastify integrations that feel native.

Stop copy-pasting rules. Get consistent, maintainable validation with sensible defaults — and only ship what you actually use.

Rules

Rule	Description
Email	Email address with domain filtering, plus-alias blocking, and disposable detection
Password	Strength rules: length, casing, digits, specials, consecutive limits, common-password ban
PasswordConfirmation	Confirms two password fields match
PersonName	Human name with unicode support, word count, and boundary rules
BusinessName	Company/organization name with boundary and consecutive limits
Phone	International phone via libphonenumber-js
Website	URL restricted to http/https with optional www and domain filtering
Url	General URL with protocol, TLD, and domain validation
Username	Alphanumeric with configurable separators and reserved-word ban
Slug	URL-safe slug (lowercase, hyphens, length limits)
PostalCode	Country-aware postal/ZIP code
LicenseKey	Software license key format (segments, separators, charset)
Uuid	UUID v1-v7 validation
Jwt	JSON Web Token structure with optional expiry checks
DateTime	Date/time string with format and range constraints
Token	Generic token validation (hex, base64, nanoid, etc.)
Text	Free text with length, word count, content detection, and regex override
Country	ISO 3166 country code (alpha-2, alpha-3)
Currency	ISO 4217 currency code
Color	Hex, RGB, HSL, and named CSS color formats
CreditCard	Card number with Luhn check and issuer detection
Iban	International Bank Account Number with country patterns
VatNumber	EU VAT identification number
MacAddress	MAC address (colon, hyphen, and dot notations)
IpAddress	IPv4 and IPv6 with optional CIDR notation

Bundle Size

Every rule shares a ~5 kB core (Brotli). Each additional rule adds 0.1-0.8 kB. Measured with esbuild --splitting + Brotli, excluding zod peer dependency.

Rule	Initial (Brotli)	On-demand data	Trigger
Email	5.7 kB	—	—
Password	5.6 kB	+0.5 kB / +3.8 kB / +35.5 kB	`blockCommon: 'basic'` / `'moderate'` / `'strict'`
PasswordConfirmation	5.7 kB	—	—
PersonName	5.7 kB	—	—
BusinessName	5.7 kB	—	—
Phone	5.7 kB	libphonenumber-js	bundled dependency
Website	5.7 kB	—	—
Url	5.6 kB	—	—
Username	5.9 kB	+0.8 kB	`blockReserved: true`
Slug	5.5 kB	—	—
PostalCode	5.4 kB	postcode-validator	bundled dependency
LicenseKey	5.5 kB	—	—
Uuid	5.3 kB	—	—
Jwt	5.6 kB	—	—
DateTime	5.6 kB	—	—
Token	5.5 kB	—	—
Text	5.5 kB	—	—
Country	5.4 kB	+2.4 kB	First use
Currency	5.4 kB	+0.3 kB	First use
Color	5.5 kB	—	—
CreditCard	5.6 kB	+0.3 kB	First use
Iban	5.5 kB	+0.7 kB	First use
VatNumber	5.5 kB	+0.3 kB	First use
MacAddress	5.3 kB	—	—
IpAddress	5.6 kB	—	—

Combination	Initial (Brotli)
Email + Password	6.0 kB
Form (Email + Password + PersonName + Phone)	6.9 kB
All 25 rules	13.0 kB

"On-demand data" loads asynchronously on first use or when the listed option is enabled. Not included in the initial bundle.

Configuration

Global defaults with `setup()`

import { setup, Email, Password } from '@validex/core'

setup({
  rules: {
    email: { blockDisposable: true },
    password: { length: { min: 10 }, special: { min: 2 } },
  },
  i18n: {
    enabled: true,
    t: (key, params) => translate(key, params),
  },
})

// Rules now use your defaults — no need to pass options every time
const emailSchema = Email()
const passwordSchema = Password()

Three-tier merge

built-in defaults  <  setup() config  <  per-call options

Per-call options override setup() config, which overrides built-in defaults. Passing undefined for a per-call option removes the global setting for that field.

import { setup, Email } from '@validex/core'

setup({ rules: { email: { blockDisposable: true } } })

Email()                              // blockDisposable: true (from setup)
Email({ blockPlusAlias: true })      // blockDisposable: true + blockPlusAlias: true
Email({ blockDisposable: undefined }) // blockDisposable removed for this call

`resetConfig()`

import { resetConfig } from '@validex/core'

resetConfig() // resets to built-in defaults

`preloadData()`

Preload async data files at startup so first validation has no delay:

import { preloadData } from '@validex/core'

await preloadData({
  disposable: true,
  passwords: 'moderate',
  reserved: true,
  phone: 'mobile',
  countryCodes: true,
  currencyCodes: true,
  ibanPatterns: true,
  vatPatterns: true,
  creditCardPrefixes: true,
  postalCodes: true,
})

Cross-Field Validation

`sameAs`

Creates a superRefine callback that verifies two fields hold the same value:

import { z } from 'zod'
import { Password, sameAs } from '@validex/core'

const schema = z.object({
  password: Password(),
  confirmPassword: z.string(),
}).superRefine(sameAs('confirmPassword', 'password', {
  message: 'Passwords do not match',
}))

PasswordConfirmation auto-wires this — it registers a sameAs: 'password' constraint automatically:

import { z } from 'zod'
import { Password, PasswordConfirmation, validate } from '@validex/core'

const schema = z.object({
  password: Password(),
  confirmPassword: PasswordConfirmation(),
})

const result = await validate(schema, {
  password: 'Str0ng!Pass',
  confirmPassword: 'different',
})
// result.firstErrors.confirmPassword → "Password Confirmation must match Password"

`requiredWhen`

Creates a superRefine callback that marks a field as required when a condition is met:

import { z } from 'zod'
import { requiredWhen } from '@validex/core'

const schema = z.object({
  accountType: z.string(),
  companyName: z.string().optional(),
}).superRefine(requiredWhen(
  'companyName',
  (data) => data['accountType'] === 'business',
  { message: 'Company name is required for business accounts' },
))

`validate()` resolves cross-field

schema.safeParse() only runs field-level validation. validate() adds cross-field checks (sameAs, requiredWhen) after Zod parsing:

// safeParse — field-level only, no cross-field
const zodResult = schema.safeParse(data)

// validate — runs field-level + cross-field
const result = await validate(schema, data)

Chainable Methods

Import @validex/core and all Zod schemas get these methods (intended for use on string schemas):

Checks (return same type, add refinement)

Method	Options	Description
`.hasUppercase(opts?)`	`min?, max?`	Requires uppercase letters
`.hasLowercase(opts?)`	`min?, max?`	Requires lowercase letters
`.hasDigits(opts?)`	`min?, max?`	Requires digits
`.hasSpecial(opts?)`	`min?, max?`	Requires special characters
`.noEmails(opts?)`	—	Blocks email addresses
`.noUrls(opts?)`	—	Blocks URLs
`.noHtml(opts?)`	—	Blocks HTML tags
`.noPhoneNumbers(opts?)`	—	Blocks phone numbers
`.noSpaces(opts?)`	—	Blocks whitespace
`.onlyAlpha(opts?)`	—	Letters only
`.onlyNumeric(opts?)`	—	Digits only
`.onlyAlphanumeric(opts?)`	—	Letters + digits
`.onlyAlphaSpaceHyphen(opts?)`	—	Letters, spaces, hyphens
`.onlyAlphanumericSpaceHyphen(opts?)`	—	Letters, digits, spaces, hyphens
`.maxWords(opts)`	`max`	Maximum word count
`.minWords(opts)`	`min`	Minimum word count
`.maxConsecutive(opts)`	`max`	Max consecutive identical chars

Transforms (return ZodPipe)

Method	Description
`.toTitleCase()`	Converts to Title Case
`.toSlug()`	Converts to URL-safe slug
`.stripHtml()`	Removes HTML tags
`.collapseWhitespace()`	Collapses multiple spaces to single
`.emptyToUndefined()`	Converts `""` to `undefined`

import { z } from 'zod'
import '@validex/core'

const schema = z.string().hasUppercase({ min: 2 }).noSpaces().toSlug()

Check Functions

Pure functions, no Zod dependency. Import from @validex/core/checks.

Composition

Function	Signature	Description
`hasUppercase`	`(value: string, min: number, max?: number) => boolean`	Uppercase letter count within `[min, max]`
`hasLowercase`	`(value: string, min: number, max?: number) => boolean`	Lowercase letter count within `[min, max]`
`hasDigits`	`(value: string, min: number, max?: number) => boolean`	Digit count within `[min, max]`
`hasSpecial`	`(value: string, min: number, max?: number) => boolean`	Special character count within `[min, max]`

Detection

Function	Signature	Description
`containsEmail`	`(value: string) => boolean`	Detects email-like patterns
`containsUrl`	`(value: string) => boolean`	Detects URL-like patterns
`containsHtml`	`(value: string) => boolean`	Detects HTML tags
`containsPhoneNumber`	`(value: string) => Promise<boolean>`	Detects phone numbers (async, uses libphonenumber-js)

Restriction

Function	Signature	Description
`onlyAlpha`	`(value: string) => boolean`	Every character is a unicode letter
`onlyNumeric`	`(value: string) => boolean`	Every character is a digit
`onlyAlphanumeric`	`(value: string) => boolean`	Every character is a letter or digit
`onlyAlphaSpaceHyphen`	`(value: string) => boolean`	Letters, spaces, hyphens only
`onlyAlphanumericSpaceHyphen`	`(value: string) => boolean`	Letters, digits, spaces, hyphens only

Limits

Function	Signature	Description
`maxWords`	`(value: string, max: number) => boolean`	At most `max` words
`minWords`	`(value: string, min: number) => boolean`	At least `min` words
`maxConsecutive`	`(value: string, max: number) => boolean`	No character repeats more than `max` times
`noSpaces`	`(value: string) => boolean`	No whitespace characters

Transforms

Function	Signature	Description
`emptyToUndefined`	`(value: unknown) => unknown`	`""` and `null` to `undefined`
`toTitleCase`	`(value: string) => string`	Title Case with hyphen/apostrophe handling
`toSlug`	`(value: string) => string`	URL-safe slug
`stripHtml`	`(value: string) => string`	Removes HTML tags
`collapseWhitespace`	`(value: string) => string`	Collapses whitespace, trims

import { hasUppercase, containsEmail, toSlug } from '@validex/core/checks'

hasUppercase('Hello', 1)    // true
containsEmail('hi@test.com') // true
toSlug('Hello World!')       // 'hello-world'

Error Handling

Error structure

Every validex error carries structured metadata via Zod's custom error params:

ctx.addIssue({
  code: 'custom',
  params: {
    code: 'disposableBlocked',
    namespace: 'email',
    label: 'Email',
    domain: 'tempmail.com',
  },
})

`getParams(issue)`

Extract structured metadata from any Zod issue:

import { Email, getParams } from '@validex/core'

const schema = Email()
const result = schema.safeParse('user@tempmail.com')

if (!result.success) {
  const params = getParams(result.error.issues[0])
  // { code: 'disposableBlocked', namespace: 'email', label: 'Email',
  //   key: 'validation.messages.email.disposableBlocked', path: [], ... }
}

Error code pattern

Keys follow: validation.messages.{namespace}.{code}

validation.messages.email.disposableBlocked
validation.messages.password.commonBlocked
validation.messages.username.reservedBlocked

`validate()` result

interface ValidationResult<T> {
  readonly success: boolean
  readonly data?: T                                    // typed parsed data (when success)
  readonly errors: Record<string, readonly string[]>   // dot-path to all messages
  readonly firstErrors: Record<string, string>         // dot-path to first message
  readonly nestedErrors: NestedErrors                  // nested object matching schema shape
  readonly issues: ReadonlyArray<unknown>              // raw Zod issues (escape hatch)
}

i18n

Setup

import { setup } from '@validex/core'

setup({
  i18n: {
    enabled: true,
    prefix: 'validation',    // default
    separator: '.',          // default
    t: (key, params) => i18next.t(key, params),
  },
})

Key pattern

validation.messages.{namespace}.{code}

When i18n.enabled is true and t() is provided, validex calls t() automatically for every error message and field label.

Label transforms

setup({
  label: {
    fallback: 'derived',  // 'derived' | 'generic' | 'none'
    transform: ({ path, fieldName, defaultLabel }) => {
      return myLabelLookup(fieldName) ?? defaultLabel
    },
  },
})

CLI

npx validex fr de --output ./locales
npx validex ja --empty --output ./locales

Full guide with all 141 error codes: Translation Guide

Custom Rules

`createRule()`

import { createRule } from '@validex/core'
import { z } from 'zod'

interface HexColorOptions {
  label?: string
  emptyToUndefined?: boolean
  normalize?: boolean
  customFn?: (value: string) => true | string | Promise<true | string>
  allowAlpha?: boolean
}

const HexColor = createRule<HexColorOptions>({
  name: 'hexColor',
  defaults: { allowAlpha: false },
  build: (opts) => {
    const pattern = opts.allowAlpha
      ? /^#[\da-f]{6,8}$/i
      : /^#[\da-f]{6}$/i
    return z.string().regex(pattern)
  },
  messages: {
    invalid: '{{label}} is not a valid hex color',
  },
})

const schema = HexColor({ allowAlpha: true })
schema.parse('#ff00aacc') // OK

`customFn`

Every rule accepts a customFn that runs after built-in checks. Return true to pass or a string to fail:

import { Email } from '@validex/core'

const schema = Email({
  customFn: (value) => value.endsWith('.org') || 'Must be a .org domain',
})

schema.parse('info@example.org')  // OK
schema.parse('info@example.com')  // throws — "Must be a .org domain"

Custom regex

Rules that extend FormatRuleOptions (like Text) accept a regex property:

import { Text } from '@validex/core'

const schema = Text({
  regex: /^[^<>]+$/,
})

Full reference: API Reference

Framework Adapters

Nuxt

pnpm add @validex/nuxt

// nuxt.config.ts
export default defineNuxtConfig({
  modules: ['@validex/nuxt'],
  validex: {
    rules: { email: { blockDisposable: true } },
  },
})

// In a component — useValidation is auto-imported
const { validate, errors, firstErrors, isValid } = useValidation(schema)

Full guide: @validex/nuxt README

Fastify

pnpm add @validex/fastify

import Fastify from 'fastify'
import { validexPlugin } from '@validex/fastify'

const app = Fastify()
await app.register(validexPlugin, {
  rules: { email: { blockDisposable: true } },
})

Full guide: @validex/fastify README

Documentation

Resource	Description
API Reference	Every rule, option, default, error code
Translation Guide	i18n setup, CLI, all 141 error codes
Contributing	Dev setup, conventions, PR workflow

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 118 Commits
.changeset		.changeset
.github		.github
.vscode		.vscode
docs		docs
packages		packages
scripts		scripts
.gitattributes		.gitattributes
.gitignore		.gitignore
.node-version		.node-version
.npmrc		.npmrc
CLAUDE.md		CLAUDE.md
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
SECURITY.md		SECURITY.md
eslint.config.ts		eslint.config.ts
knip.json		knip.json
package.json		package.json
pnpm-lock.yaml		pnpm-lock.yaml
pnpm-workspace.yaml		pnpm-workspace.yaml
tsconfig.base.json		tsconfig.base.json
tsconfig.json		tsconfig.json
vitest.config.base.ts		vitest.config.base.ts

Folders and files

Latest commit

History

Repository files navigation

validex

Install

Quick Start

Single rule

Rule with options

Composed schema with validate()

Why validex?

Rules

Bundle Size

Configuration

Global defaults with setup()

Three-tier merge

resetConfig()

preloadData()

Cross-Field Validation

sameAs

requiredWhen

validate() resolves cross-field

Chainable Methods

Checks (return same type, add refinement)

Transforms (return ZodPipe)

Check Functions

Composition

Detection

Restriction

Limits

Transforms

Error Handling

Error structure

getParams(issue)

Error code pattern

validate() result

i18n

Setup

Key pattern

Label transforms

CLI

Custom Rules

createRule()

customFn

Custom regex

Framework Adapters

Nuxt

Fastify

Documentation

License

About

Topics

Resources

License

Code of conduct

Contributing

Security policy

Uh oh!

Stars

Watchers

Forks

Releases 3

Contributors

Uh oh!

Languages

Composed schema with `validate()`

Global defaults with `setup()`

`resetConfig()`

`preloadData()`

`sameAs`

`requiredWhen`

`validate()` resolves cross-field

`getParams(issue)`

`validate()` result

`createRule()`

`customFn`