Regle

Regle is a type-safe, model-based, headless form validation library for Vue 3. It provides full TypeScript inference, reactive validation, and works with any UI framework or design system.

MCP Server

Regle provides an MCP server that can be used to get documentation and autocomplete for Regle. If it's available, use it to get up-to-date information on the API.

{
  "mcpServers": {
    "regle": {
      "command": "npx",
      "args": ["@regle/mcp-server"]
    }
  }
}

## Installation

```sh
# Core + built-in rules
pnpm add @regle/core @regle/rules

# Optional: schema support (Zod, Valibot, ArkType)
pnpm add @regle/schemas

Requires Vue 3.3+ and TypeScript 5.1+.

Quick Start

import { useRegle } from '@regle/core';
import { required, email, minLength } from '@regle/rules';

const { r$ } = useRegle(
  { name: '', email: '' },
  {
    name: { required, minLength: minLength(3) },
    email: { required, email },
  }
);

<template>
  <input v-model="r$.$value.name" placeholder="Name" />
  <ul v-if="r$.$errors.name.length">
    <li v-for="error of r$.$errors.name" :key="error">{{ error }}</li>
  </ul>

  <button @click="r$.$validate()">Submit</button>
</template>

Key Concepts

State: first argument -- raw object, reactive, ref, or single value
Rules: second argument -- mirrors the data structure, each field gets a rules object
r$: returned reactive object with values, errors, dirty state, and validation methods
All rules are optional by default; add required to enforce a field

Core

Topic	Description	Reference
useRegle	State definition, rules declaration, dynamic rules, `r$` object	core-use-regle
Validation Properties	`$invalid`, `$dirty`, `$error`, `$errors`, `$pending`, `$validate`, `$touch`, `$reset`	core-validation-properties
Displaying Errors	Showing errors, custom messages, `getErrors`, `flatErrors`	core-displaying-errors
Modifiers	`autoDirty`, `lazy`, `silent`, `rewardEarly`, `disabled`, `validationGroups`, per-field modifiers	core-modifiers

Related skills

regle-rules — built-in rules, custom rules (createRule), rule wrappers (withMessage, withParams, withAsync), and rule operators (and, or, applyIf, assignIf).
regle-advanced — collections, async, server errors, reset, scoped validation, variants, global config.
regle-schemas — Zod, Valibot, ArkType, and Standard Schema integration.
regle-typescript — type-safe output, typing rules schemas and component props.