mint/api-v13/app/Models/Relation.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Relation extends Model
{
    use HasFactory;

    protected $casts = [
        'id' => 'string',
    ];

    protected $fillable = ['id', 'name', 'case', 'to'];
}