hado/core/app/Models/Delivery.php

<?php

namespace App\Models;

use App\Enums\DeliveryResult;
use App\Models\Concerns\StoresUtc;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class Delivery extends Model
{
    use StoresUtc;

    protected $guarded = [];

    protected $attributes = ['meta' => '{}'];

    protected function casts(): array
    {
        return [
            'result' => DeliveryResult::class,
            'window_start' => 'immutable_datetime',
            'sent_at' => 'immutable_datetime',
            'meta' => 'array',
        ];
    }

    public function event(): BelongsTo
    {
        return $this->belongsTo(Event::class);
    }

    public function channel(): BelongsTo
    {
        return $this->belongsTo(Channel::class);
    }
}