Outbound REST Calls in ServiceNow: RESTMessageV2 Complete Guide

Basic GET request

var rm = new sn_ws.RESTMessageV2();
rm.setHttpMethod('GET');
rm.setEndpoint('https://api.example.com/v1/users');
rm.setRequestHeader('Authorization', 'Bearer ' + token);
rm.setRequestHeader('Content-Type', 'application/json');

var response = rm.execute();
var statusCode = response.getStatusCode();
var body = response.getBody();

if (statusCode == 200) {
    var data = JSON.parse(body);
    gs.log('Users returned: ' + data.users.length);
} else {
    gs.error('API call failed: ' + statusCode + ' - ' + body);
}

POST request with JSON body

var rm = new sn_ws.RESTMessageV2();
rm.setHttpMethod('POST');
rm.setEndpoint('https://api.example.com/v1/incidents');
rm.setRequestHeader('Content-Type', 'application/json');
rm.setRequestHeader('Authorization', 'Bearer ' + token);

var payload = {
    title: current.getValue('short_description'),
    severity: current.getValue('urgency'),
    reference: current.getValue('number')
};
rm.setRequestBody(JSON.stringify(payload));

var response = rm.execute();
var statusCode = response.getStatusCode();

Using a named REST Message

For reusable configurations, create a REST Message record at System Web Services > Outbound > REST Message. Define base URL, authentication, and HTTP methods. Then call it by name:

var rm = new sn_ws.RESTMessageV2('My External API', 'Create Incident');
rm.setStringParameterNoEscape('short_description', current.getValue('short_description'));
var response = rm.execute();

Asynchronous execution

// Returns immediately, response handled via callback
rm.executeAsync(callbackFunctionName);

Error handling

try {
    var response = rm.execute();
    if (response.getStatusCode() >= 400) {
        gs.error('HTTP error: ' + response.getStatusCode());
    }
} catch (ex) {
    gs.error('REST call failed: ' + ex.getMessage());
}