Use nlapiRequestURL to make a request to a Service - netsuite

Question

How do you use nlapiRequestURL to make a request to a service? My attempt below is failing with the error: UNEXPECTED_ERROR (output from NetSuites script execution log).
My service is set to run without login and works correctly when I directly access it through a browser using its url. Its just the request through nlapiRequestURL thats failing.
Any idea what could be going wrong?
// This code executes in Account.Model.js (register function)
// I am using my own netsuite user credential here
var cred = {
email: "MY_NETSUITE_EMAIL"
, account: "EXXXXX" // My account id
, role: "3" // Administrator
, password: "MY_NETSUITE_PASSWORD"
};
var headers = {"User-Agent-x": "SuiteScript-Call",
"Authorization": "NLAuth nlauth_account=" + cred.account + ", nlauth_email=" + cred.email +
", nlauth_signature= " + cred.password + ", nlauth_role=" + cred.role,
"Content-Type": "application/json"};
var payload = {
type: 'is_email_valid'
, email: 'spt015#foo.com'
};
// A raw request to the service works fine:
// http://mywebsite.com/services/foo.ss?type=is_email_valid&email=spt015#foo.com
// Error occurs on next line
var response = nlapiRequestURL(url, payload, headers);

Answer 1

You are attempting to call a non-Netsuite url with Netsuite authentication headers. You do not need that unless for some reason of your own you have implemented NS-style authorization on your service.
nlapiRequestURL does not automatically format a payload into a query string. If your service takes a posted JSON body then you need to call JSON.stringify(payload) e.g
var response = nlapiRequestURL(url, JSON.stringify(payload), headers);
If your service needs a query string like in your example then you need to construct a query string and append it to your service url. e.g.
var qs = '';
for(var k in payload) qs += k +'='+ uriEncodeComponent(payload[k]) +'&';
var response = nlapRequestURL(url +'?'+ qs.slice(0,-1), null, headers);

Answer 2

I would suggest changing your nlapiRequestURL to a GET instead of POST, and add the parameters to the url instead. Your function call will look like this instead.
nlapiRequestURL(url, null, headers, "GET")