You can send outbound REST requests from any place in the Now Platform where scripting is allowed.

For example, you can return data from a REST endpoint using a business rule when an event is triggered. Create a script from scratch or let the REST message preview feature create the script based on content and parameters you provide in the method record.

For detailed API information about the server-side RESTMessageV2 and RESTResponseV2 APIs, see the API documentation on developer.servicenow.com. For additional tips and best practices, see the Outbound REST Web Services RESTMessageV2 and SOAPMessageV2 execute() vs executeAsync() Best Practices [KB0694711] article in the Now Support Knowledge Base.