Starting with Laravel 8, you may define an accessor and mutator using a single, non-prefixed method which returns an Illuminate\Database\Eloquent\Casts\Attribute.

Before

public function getFirstNameAttribute($value)
{
    return ucfirst($value);
}
 
public function setFirstNameAttribute($value)
{
    $this->attributes['first_name'] = strtolower($value);
}

After

protected function firstName(): Attribute
{
    return new Attribute(
        get: fn ($value) => ucfirst($value),
        set: fn ($value) => strtolower($value),
    );
}