First stable release of yiisoft/hydrator-validator was tagged.
The package provides a hydrator that also does validation, including raw data. It's useful when input data comes from a user, and you need to validate it and then put it into DTOs.
To use it, the object being validated must implement ValidatedInputInterface. You can use ValidatedInputTrait to
easily create such object. The validation rules for raw values of the object are defined with Validate PHP attribute.
Example of object:
use Yiisoft\Hydrator\Validator\Attribute\Validate;
use Yiisoft\Hydrator\Validator\ValidatedInputInterface;
use Yiisoft\Hydrator\Validator\ValidatedInputTrait;
use Yiisoft\Validator\Rule\Email;
use Yiisoft\Validator\Rule\Required;

final class InputDto implements ValidatedInputInterface
{
use ValidatedInputTrait;

#[Email]
private string $email;

#[Validate(new Required())]
private string $name;
}

Validation result could be obtained via its getValidationResult() method.
Validating hydrator usage example:
use Yiisoft\Hydrator\HydratorInterface;
use Yiisoft\Hydrator\Validator\ValidatingHydrator;

public function actionEdit(RequestInterface $request, ValidatingHydrator $hydrator): ResponseInterface
{
$data = $request->getParsedBody();
$inputDto = $hydrator->create(InputDto::class, $data);

if (!$inputDto->getValidationResult()->isValid()) {
// Validation didn't pass :(
}

// Everything is fine. You can use $inputDto now.
}