Lumen provides several different approaches to validate your application's incoming data. By default, Lumen's base controller class uses a ProvidesConvenienceMethods trait which provides a convenient method to validate incoming HTTP request with a variety of powerful validation rules.

In general, validation in Lumen works exactly like validation in Laravel, so you should consult the full Laravel validation documentation; however, there are a few important differences.

Differences From Laravel

Form Requests

Form requests are not supported by Lumen. If you would like to use form requests, you should use the full Laravel framework.

The $this->validate Method

The $this->validate helper which is available in Lumen will always return a JSON response with the relevant error messages. This is in contrast to the Laravel version of the method which will return a redirect response if the request is not an AJAX request. Since Lumen is stateless and does not support sessions, flashing errors to the session is not a possibility. If you would like to use redirects and flashed error data, you should use the full Laravel framework.

Unlike Laravel, Lumen provides access to the validate method from within Route closures:

use Illuminate\Http\Request;

$app->post('/user', function (Request $request) {
    $this->validate($request, [
        'name' => 'required',
        'email' => 'required|email|unique:users'

    // Store User...

Of course, you are free to manually create validator instances using the Validator::make facade method just as you would in Laravel.

The $errors View Variable

Lumen does not support sessions out of the box, so the $errors view variable that is available in every view in Laravel is not available in Lumen. Should validation fail, the $this->validate helper will throw Illuminate\Validation\ValidationException with embedded JSON response that includes all relevant error messages. If you are not building a stateless API that solely sends JSON responses, you should use the full Laravel framework.