Join pivot has one array

I guys, i have 2 relations tables, and when listing all my messages, is shown the pivot columns relation, but i need to show the data has one array, is there a method in eloquent cant make this happen?

I searched and i no that is possible manipulate with collection methods but i wonder if there is another way.

My Model query is:

   public function messages()
    {

        return $this->belongsToMany(Message::class,'message_users')->withPivot('is_read','sent_at');
    }

This is how it is:

{
    "data": [
        {
            "id": 4,
            "title": "test",
            "body": "<p>test</p>",
            "pivot": {
                "user_id": 1,
                "message_id": 4,
                "is_read": 0,
                "sent_at": "2019-06-05 12:59:11"
            }
        }
    ]
}

This is how i want:

{
    "data": [
        {
            "id": 4,
            "title": "test",
            "body": "<p>test</p>",
            "user_id": 1,
            "message_id": 4,
            "is_read": 0,
            "sent_at": "2019-06-05 12:59:11"
        }
    ]
}

via Chebli Mohamed