solarai/app/Http/Middleware/ConvertStringBooleans.php

<?php
namespace App\Http\Middleware;

use Illuminate\Foundation\Http\Middleware\TransformsRequest;

class ConvertStringBooleans extends TransformsRequest
{
    protected function transform($key, $value)
    {
        if($value === 'true' || $value === 'TRUE') return true;
        if($value === 'false' || $value === 'FALSE') return false;
        return $value;
    }
}