Why Script Includes and GlideAjax Changed How I Build in ServiceNow

[BillMartin]

When I started building apps on ServiceNow, I did what most of us do.

I opened up a Business Rule…
typed out a GlideRecord…
and maybe threw in a g_form.setValue() if I was feeling fancy.

It worked.

Until it didn’t.

As my app grew, so did the mess.

I had duplicate logic scattered across Client Scripts, UI Policies, and Background Scripts.
Every new feature felt like a risky surgery on a spaghetti bowl of GlideRecord calls.
I couldn’t test anything in isolation.
I couldn’t trace why things were breaking.
And I couldn’t sleep knowing every change might break something else.

Then I discovered Script Includes.

Not just as a place to dump shared code, but as the first step toward real software architecture on the platform.

The Turning Point

I remember the exact day it clicked.

I needed to run a complex query on the client side.
I googled, experimented, failed… and then found GlideAjax + Script Include.

Suddenly, I wasn’t limited to client-side guesswork anymore.

I wrote a Script Include to encapsulate the logic, exposed only the method I needed, and called it from the client using GlideAjax.

It felt magical:

• Clean separation of concerns

• Reusable logic

• Secure server-side execution

• Simple JSON-like responses

That’s when I realized…

ServiceNow isn’t just a platform. It’s a place where real software design lives—if you treat it like one.

Object-Oriented Programming in a ServiceNow Platform World

As I started building more Script Includes, I stopped thinking in functions… and started thinking in objects.

I created:

• IncidentService classes to encapsulate logic

• GlideRecordHelper to handle CRUD operations generically

• BaseLogger to standardize logging across modules

• ResponseObject to wrap every result with success/failure

I grouped related logic into repositories.
I wrapped everything in try/catch blocks with clean error handling.
And I finally understood why patterns like Dependency Injection matter—even in JavaScript.

The code got cleaner.
The bugs became easier to track.
And for the first time in months, the app felt like something I could proudly scale.

Lessons I Wish I Knew Earlier

• Script Includes are not just utilities—they’re your classes. Treat them like it.

• GlideAjax is your gateway to architecture on the client side. Use it with intention.

• If you write the same logic twice, it belongs in a service or repository.

• Logging is not optional—add it, and you’ll thank yourself later.

• Architecture isn’t overkill. It’s your parachute when complexity grows.

Want to See It in Action?

If you're curious how all of this ties together—Script Includes, GlideAjax, OOP, and clean architecture—I’ve captured everything in a real working example on YouTube.

Watch the full tutorial series here 

Final Thought

If you're just getting started with Script Includes, don’t worry about perfection.
Just start separating logic, naming your methods well, and calling them from GlideAjax.

Before you know it, you’ll look back at your old scripts and smile—not because they were bad, but because they led you here.

To real architecture.
To clean code.
To confidence.

And that, in my opinion, is the real power of ServiceNow.

Let’s keep building.