Make an outbound REST call with RESTMessageV2

The critical mistake developers make with RESTMessageV2 is parsing the response body without checking the HTTP status first. ServiceNow will happily return a 404 error page as HTML, and JSON.parse() will explode. Always validate getStatusCode() before touching getBody(). The platform doesn't throw exceptions for HTTP errors — it just returns them as successful responses with error status codes.

When to use this

• Server-side integrations in Business Rules, Script Includes, or Scheduled Jobs
• When you need full control over HTTP headers and error handling
• API calls that require authentication tokens or custom headers
• One-off or dynamic endpoints that don't warrant creating a REST Message record

When NOT to use this

• Client-side scripts — use GlideAjax with a Script Include wrapper instead
• Repeated calls to the same endpoint — create a REST Message record and use RESTMessageV2(messageName, httpMethod)
• Inside loops over large datasets — you'll create timeout and performance issues
• When the external system is unreliable — use async patterns with retry logic instead

Key behaviors and gotchas

• Always URL-encode dynamic path parameters with encodeURIComponent() to prevent injection
• HTTP status codes 400-599 don't throw exceptions — check getStatusCode() explicitly
• Default timeout is 30 seconds — use setHttpTimeout() for longer operations
• Empty response bodies return empty string, not null — check before parsing JSON
• Network exceptions (DNS failures, connection refused) throw JavaScript exceptions
• MID Server calls require different error handling — response object behavior varies