What Is the Custom Tool Script Type?

NetSuite’s 2025.2 release introduces a new SuiteScript classification: the Custom Tool Script Type. This script type is designed to encapsulate reusable logic — especially for AI-powered interactions — that can be invoked across multiple contexts like workflows, Suitelets, RESTlets, and scheduled scripts.

Unlike traditional script types (User Event, Client, Map/Reduce), Custom Tool Scripts are modular, context-agnostic, and ideal for embedding intelligent automation into NetSuite’s ecosystem.

Why It Matters

Before this update, developers had to duplicate logic across multiple scripts or build brittle integrations to external services. The Custom Tool Script Type solves this by allowing you to:

Centralize AI logic (e.g., prompt generation, response parsing)

Reuse across multiple NetSuite components

Deploy and version via SuiteCloud Development Framework (SDF)

Maintain clean separation between business logic and interface layers

Example Use Case: AI-Powered Customer Response Generator

Imagine a tool that generates personalized email replies based on support case descriptions. With the Custom Tool Script Type, you can build this once and invoke it from:

A Suitelet that previews the response

A Workflow that sends the email

A RESTlet that triggers it from an external CRM

Sample Tool Script Structure

/**

 * @NApiVersion 2.1

 * @NScriptType CustomTool

 */

define([‘N/aiConnector’], function(aiConnector) {

 function execute(context) {

  var prompt = {

   model: ‘openai-gpt4’,

   input: context.parameters.caseDescription

  };

  var response = aiConnector.sendPrompt(prompt);

  return { reply: response.output };

 }

 return { execute: execute };

});