Request Validation

AdonisJS uses VineJS for request validation, providing a type-safe and expressive way to validate incoming HTTP request data.

Basic validation

Validate request data using the request.validateUsing() method:

import router from '@adonisjs/core/services/router'
import vine from '@vinejs/vine'

// Define a validator
const createUserValidator = vine.compile(
  vine.object({
    email: vine.string().email(),
    name: vine.string().minLength(3),
    password: vine.string().minLength(8)
  })
)

// Use in route handler
router.post('/users', async ({ request }) => {
  const data = await request.validateUsing(createUserValidator)
  
  // data is now typed as { email: string, name: string, password: string }
  const user = await User.create(data)
  return { user }
})

RequestValidator class

The RequestValidator class from modules/http/request_validator.ts:34 integrates VineJS with AdonisJS requests:

import { RequestValidator } from '@adonisjs/core/http'

/**
 * The RequestValidator provides:
 * - Automatic validation of request body, files, URL parameters, headers, and cookies
 * - Custom error reporters per request
 * - Custom message providers per request
 */

Validation data

By default, request.validateUsing() validates:

Request body
Uploaded files
URL parameters (available as params)
Request headers (available as headers)
Cookies (available as cookies)

Validating request body

const updateUserValidator = vine.compile(
  vine.object({
    email: vine.string().email().optional(),
    name: vine.string().minLength(3).optional(),
    bio: vine.string().maxLength(500).optional()
  })
)

router.patch('/users/:id', async ({ request }) => {
  const data = await request.validateUsing(updateUserValidator)
  // Only includes fields from request body
})

Validating URL parameters

const showUserValidator = vine.compile(
  vine.object({
    params: vine.object({
      id: vine.number()
    })
  })
)

router.get('/users/:id', async ({ request }) => {
  const { params } = await request.validateUsing(showUserValidator)
  // params.id is now a number
})

Validating headers

const apiRequestValidator = vine.compile(
  vine.object({
    headers: vine.object({
      'api-key': vine.string(),
      'accept': vine.string()
    })
  })
)

router.post('/api/data', async ({ request }) => {
  const { headers } = await request.validateUsing(apiRequestValidator)
  // headers are validated
})

Validating cookies

const cookieValidator = vine.compile(
  vine.object({
    cookies: vine.object({
      session_id: vine.string()
    })
  })
)

router.get('/dashboard', async ({ request }) => {
  const { cookies } = await request.validateUsing(cookieValidator)
  // cookies.session_id is validated
})

Custom validation data

Provide custom data to validate:

router.post('/users', async ({ request }) => {
  const customData = {
    email: 'user@example.com',
    name: 'John Doe'
  }
  
  const data = await request.validateUsing(createUserValidator, {
    data: customData
  })
})

Error handling

Validation errors throw a ValidationError:

import { errors as vineErrors } from '@vinejs/vine'

router.post('/users', async ({ request, response }) => {
  try {
    const data = await request.validateUsing(createUserValidator)
    const user = await User.create(data)
    return { user }
  } catch (error) {
    if (error instanceof vineErrors.E_VALIDATION_ERROR) {
      return response.badRequest({
        errors: error.messages
      })
    }
    throw error
  }
})

Try validation

Use tryValidateUsing() for validation without throwing errors:

router.post('/users', async ({ request, response }) => {
  const [error, data] = await request.tryValidateUsing(createUserValidator)
  
  if (error) {
    return response.badRequest({
      errors: error.messages
    })
  }
  
  const user = await User.create(data)
  return { user }
})

From modules/http/request_validator.ts:134:

/**
 * Returns a tuple of [ValidationError, null] on failure
 * or [null, ValidatedData] on success
 */
async tryValidateUsing<Schema, MetaData>(
  validator: VineValidator<Schema, MetaData>,
  options?: RequestValidationOptions<MetaData>
): Promise<[ValidationError, null] | [null, Infer<Schema>]>

Custom error reporters

Customize how validation errors are reported:

import { SimpleErrorReporter } from '@vinejs/vine'
import { RequestValidator } from '@adonisjs/core/http'

// Set global error reporter
RequestValidator.errorReporter = ({ request }) => {
  // Return custom error reporter based on request
  if (request.accepts(['json'])) {
    return new SimpleErrorReporter()
  }
  return new SimpleErrorReporter()
}

Per-request error reporter

import { SimpleErrorReporter } from '@vinejs/vine'

router.post('/users', async ({ request }) => {
  const data = await request.validateUsing(createUserValidator, {
    errorReporter: () => new SimpleErrorReporter()
  })
})

Custom messages

Provide custom validation messages:

import { SimpleMessagesProvider } from '@vinejs/vine'
import { RequestValidator } from '@adonisjs/core/http'

// Set global messages provider
RequestValidator.messagesProvider = () => {
  return new SimpleMessagesProvider({
    required: 'The {{ field }} field is required',
    'email.email': 'Please provide a valid email address',
    'password.minLength': 'Password must be at least {{ min }} characters'
  })
}

Per-request messages

import { SimpleMessagesProvider } from '@vinejs/vine'

const customMessages = new SimpleMessagesProvider({
  required: 'This field cannot be empty',
  'email.email': 'Invalid email format'
})

router.post('/users', async ({ request }) => {
  const data = await request.validateUsing(createUserValidator, {
    messagesProvider: customMessages
  })
})

Validation metadata

Pass metadata to validators for dynamic validation:

const createUserValidator = vine.withMetaData<{ disallowUserNames: string[] }>().compile(
  vine.object({
    username: vine.string().notIn((field) => {
      return field.meta.disallowUserNames
    })
  })
)

router.post('/users', async ({ request }) => {
  const data = await request.validateUsing(createUserValidator, {
    meta: {
      disallowUserNames: ['admin', 'root', 'system']
    }
  })
})

Creating validators

Inline validators

router.post('/posts', async ({ request }) => {
  const data = await request.validateUsing(
    vine.compile(
      vine.object({
        title: vine.string().minLength(5),
        content: vine.string(),
        published: vine.boolean()
      })
    )
  )
})

Reusable validators

Create validators in separate files:

// app/validators/user.ts
import vine from '@vinejs/vine'

export const createUserValidator = vine.compile(
  vine.object({
    email: vine.string().email(),
    name: vine.string().minLength(3),
    password: vine.string().minLength(8)
  })
)

export const updateUserValidator = vine.compile(
  vine.object({
    email: vine.string().email().optional(),
    name: vine.string().minLength(3).optional(),
    bio: vine.string().maxLength(500).optional()
  })
)

Use in controllers:

import { createUserValidator, updateUserValidator } from '#validators/user'

export default class UsersController {
  async store({ request }: HttpContext) {
    const data = await request.validateUsing(createUserValidator)
    const user = await User.create(data)
    return { user }
  }
  
  async update({ request, params }: HttpContext) {
    const data = await request.validateUsing(updateUserValidator)
    const user = await User.findOrFail(params.id)
    await user.merge(data).save()
    return { user }
  }
}

Common validation rules

String validation

vine.object({
  email: vine.string().email(),
  url: vine.string().url(),
  username: vine.string().minLength(3).maxLength(20),
  bio: vine.string().maxLength(500).optional(),
  role: vine.enum(['admin', 'user', 'moderator'])
})

Number validation

vine.object({
  age: vine.number().min(18).max(100),
  price: vine.number().positive(),
  quantity: vine.number().min(1),
  rating: vine.number().min(1).max(5).optional()
})

Boolean validation

vine.object({
  isPublished: vine.boolean(),
  acceptTerms: vine.boolean().isTrue() // Must be true
})

Array validation

vine.object({
  tags: vine.array(vine.string()).minLength(1).maxLength(5),
  ids: vine.array(vine.number()),
  roles: vine.array(vine.enum(['admin', 'user']))
})

Object validation

vine.object({
  profile: vine.object({
    firstName: vine.string(),
    lastName: vine.string(),
    age: vine.number().optional()
  })
})

File validation

vine.object({
  avatar: vine.file({
    size: '2mb',
    extnames: ['jpg', 'png', 'jpeg']
  }),
  documents: vine.array(
    vine.file({
      size: '5mb',
      extnames: ['pdf', 'doc', 'docx']
    })
  ).optional()
})

Best practices

Always validate user input

Never trust user input. Always validate data before processing:

const data = await request.validateUsing(validator)
// Now data is validated and type-safe

Create reusable validators

Store validators in a dedicated directory for reuse:

app/
└── validators/
    ├── user.ts
    ├── post.ts
    └── comment.ts

Use TypeScript for type safety

VineJS validators provide full TypeScript support:

const data = await request.validateUsing(createUserValidator)
// data is typed as { email: string, name: string, password: string }

Handle validation errors gracefully

Provide clear error messages to users:

const [error, data] = await request.tryValidateUsing(validator)

if (error) {
  return response.badRequest({
    message: 'Validation failed',
    errors: error.messages
  })
}

VineJS Documentation

Learn more about VineJS validation rules and features

Get Started

Architecture

HTTP

Ace CLI

Core Modules

Advanced

Basic validation

RequestValidator class

Validation data

Validating request body

Validating URL parameters

Validating headers

Validating cookies

Custom validation data

Error handling

Try validation

Custom error reporters

Per-request error reporter

Custom messages

Per-request messages

Validation metadata

Creating validators

Inline validators

Reusable validators

Common validation rules

String validation

Number validation

Boolean validation

Array validation

Object validation

File validation

Best practices

Further reading

VineJS Documentation

Build docs developers (and LLMs) love

Get Started

Architecture

HTTP

Ace CLI

Core Modules

Advanced

Documentation Index

​Basic validation

​RequestValidator class

​Validation data

​Validating request body

​Validating URL parameters

​Validating headers

​Validating cookies

​Custom validation data

​Error handling

​Try validation

​Custom error reporters

​Per-request error reporter

​Custom messages

​Per-request messages

​Validation metadata

​Creating validators

​Inline validators

​Reusable validators

​Common validation rules

​String validation

​Number validation

​Boolean validation

​Array validation

​Object validation

​File validation

​Best practices

​Further reading

VineJS Documentation

Build docs developers (and LLMs) love

Basic validation

RequestValidator class

Validation data

Validating request body

Validating URL parameters

Validating headers

Validating cookies

Custom validation data

Error handling

Try validation

Custom error reporters

Per-request error reporter

Custom messages

Per-request messages

Validation metadata

Creating validators

Inline validators

Reusable validators

Common validation rules

String validation

Number validation

Boolean validation

Array validation

Object validation

File validation

Best practices

Further reading