```php
<?php

require_once '../../core/api_bootstrap.php';
require_once '../../services/crud_service.php';

$data=Request::post();

Validator::required($data,['id','state_id','name']);

$db=new Database();
$conn=$db->connect();

$crud=new CrudService($conn);

$crud->update('cities',[
'state_id'=>$data['state_id'],
'name'=>Helper::sanitize($data['name']),
'status'=>$data['status'] ?? 1
],$data['id']);

Response::success([],"City updated");