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title: SDK Overview
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---

# SDK Overview

Noodl SDK, or `@noodl/noodl-sdk`, is a javascript package that is making is easy to extend Noodl with core nodes.

## Installation

Here are some guides on how to create a Noodl module, including installing the SDK.
[Continue here.](/javascript/extending/overview)

## Getting started

We have a lot of open source modules in this [GitHub repository](https://github.com/noodlapp/modules).
These are a great place to start when looking for references, and examples of how to build a module.

Not all of these modules are made with the SDK. Why?
The SDK is built on top of the internal Noodl API, designed to make it easier and future compatible with internal Noodl API changes in mind.
Currently the SDK does lack some of the functionality that the internal Noodl API provides, which is the primary reason not to use the SDK for these modules.
In the end the module code will be very similar, but can cause some confusion.

> At this time, the only module that is not built using the SDK in that GitHub repository is the `simple-tooltips` module.

For a module to be registered in the Noodl app, you don't need to have the SDK installed.
The way that the modules are registered is by calling the `Noodl.defineModule(module)` function which is globally defined by the Noodl runtime and not in the SDK.
