Validation

Lumen provides several different approaches to validate your application's incoming data. By default, Lumen's base controller class uses a 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

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:

The exists And unique Rules

If you would like to use the exists or unique validation rules, you should uncomment the method call in your bootstrap/app.php file.

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 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.