This one looks critical to me. Can any maintainer say what kind of documentation you want?

Possibilities I see are:

• a new dedicated page
• a new section inside the middleware

For the record adding it to the middleware list is to do like this:

framework:
    messenger:
        buses:
            command_bus:
                middleware:
                    - messenger.middleware.validation

class CreateUser
{
    /**
     * @Assert\Uuid()
     * @Assert\NotBlank()
     */
    private $uuid;

    /**
     * @Assert\Lenght(min=3)
     * @Assert\NotBlank()
     */
    private $username;

    public function __construct(string $uuid, string $username)
    {
        $this->uuid = $uuid;
        $this->username = $username;
    }

    public function getUuid(): string
    {
        return $this->uuid;
    }

    public function getUsername(): string
    {
         return $this->username;
    }
}

The middleware will throw a ValidationFailedException that you may handle onKernelException and return formatted errors (in the case of an API for instance).

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?

no

@Nek- @ogizanagi I’ve opened a related PR
Feel free to discuss it :)