Salesforce Marketing Cloud

Server-Side JavaScript
Reference Guide

Everything you need to write, debug, and master SSJS in SFMC — global functions, Platform APIs, Core library, WSProxy, HTTP, engine limitations, and real-world recipes.

Get Started Function Index

Reference

Global Functions

Top-level functions available in every SSJS context: Write, Stringify, TreatAsContent, content blocks, and more.

Platform Functions

The Platform.Function.* API surface — Data Extension CRUD, strings, dates, crypto, HTTP, AMPscript bridge, and SOAP helpers.

Platform Objects

Platform.Load, Platform.Variable, Platform.Response, Platform.Request, and Platform.ClientBrowser.

5 objects · 22 methods

SOAP-style object wrappers after Platform.Load("core","1.1.5") — DataExtension, Subscriber, Email, TriggeredSend, and 20+ more.

The fastest way to call the SFMC SOAP API from SSJS. new WSProxy() with retrieve, create, update, delete, batch, and impersonation.

All HTTP options compared: HTTP.Get/Post, Platform.Function.HTTPGet, and Script.Util.HttpRequest for full REST verb support.

3 approaches · 9 functions

Guides

Getting Started

What SSJS is, where it runs, how to embed script blocks, execution contexts, and the difference between Platform and Core.

Variables, types, operators, control flow, loops, functions, objects, JSON, error handling — the ES3/5 subset that works in SFMC.

Engine Limitations

24 ES6+ features that fail at runtime, broken Array methods, polyfills you need, and known platform bugs like the switch default issue.

4 topics · 20 polyfills

ECMAScript Builtins

Safe Array, String, and Math methods that work in the SFMC SSJS engine — tested and documented with examples.

31 safe methods

Debugging techniques, performance patterns, security considerations, style guide, and defensive coding for SFMC SSJS.

Copy-paste patterns for Cloud Page apps, AMPscript bridging, REST API calls, DE CRUD, subscribers, anti-CSRF, and encryption.

Quick Start

A minimal SSJS CloudPage:

<script runat="server">
Platform.Load("core", "1.1.5");

try {
    var subscriberKey = Platform.Request.GetQueryStringParameter("sk");

    if (subscriberKey) {
        var email = Platform.Function.Lookup(
            "Subscribers",
            "EmailAddress",
            "SubscriberKey",
            subscriberKey
        );
        Write("<p>Hello, " + email + "</p>");
    }
} catch (e) {
    Write("<p>Error: " + Stringify(e) + "</p>");
}
</script>

Key points:

SSJS runs on the server inside <script runat="server"> blocks
Platform.Load("core", "1.1.5") must be called before using Core library objects
The engine is roughly ES3/5 — no arrow functions, let/const, template literals, or async/await
Use Write() to output HTML, Stringify() to serialize objects, Platform.Function.ParseJSON() instead of JSON.parse()

→ Read the full Getting Started guide