I'm creating a RESTful API using PHP to distribute all my requests to the right place (one of them is Odoo).

So I was using the API reference and I'm trying to register a user using the API.

The request is made using:
$id = $model->execute_kw($db, $uid, $pass, 'res.users', 'create', [['name' => $data->fullName, 'login' => $data->username, 'new_password' => $data->password]]);

The response is: 
{"faultCode":4,"faultString":"(u'The requested operation cannot be completed due to security restrictions. Please contact your system administrator.\\n\\n(Document type: Users, Operation: write)', None)"}

The $model param is instantiated correctly, because I can use the 'search_read' action with success.

I'm fairly new to Odoo so go soft on me :).