Software Development Kit (SDK)

A Software Development Kit (SDK) is a set of tools, libraries, and documentation that helps developers build new features or integrate external services into an app, website, or digital platform.

For example, if you want to send real-time push notifications in your e-commerce app, you can integrate a mobile SDK to handle that; no need to code the entire notification system yourself.

Why Use an SDK?

  • Pre-built SDK libraries, APIs, and widgets make it faster and easier for your team to integrate complex features like analytics, messaging, or payments without deep custom development.​
  • SDKs offer compatibility with their parent platform and are regularly updated for security, making app maintenance and compliance more manageable.​
  • SDKs can be used to tap into features such as customer measurement, campaign personalization, or mobile-specific actions (e.g., location triggers), giving your digital products a competitive edge.

SDK vs. API 

FeatureSDKAPI
What it isFull toolkit (code, docs, tools)Preset way to access data/service
Use caseBuild or extend an appConnect two systems
Typical contentLibraries, docs, test toolsEndpoints, docs
Technical skills neededDeveloperDeveloper
ExampleAdd in-app messages to appPull users from CRM

FAQs

What’s included in a typical SDK?

A typical SDK includes libraries, sample projects, APIs, integration documentation, debugging tools, and sometimes a testing environment. These elements make it easier for developers to add features like messaging, analytics, or payments quickly. For a practical look at how SDKs enable real-time mobile engagement, check out Insider One’s web SDK guide.

What is the difference between an SDK and an API?

An API (Application Programming Interface) provides a defined way for systems to communicate by requesting or exposing data. In contrast, an SDK bundles the API plus libraries, code examples, testing tools, and deeper integrations to build functionality into a platform. In other words, APIs enable connectivity, and SDKs allow construction.

Do SDKs support ongoing updates?

Yes, SDKs are maintained by their publishers and regularly updated for new features, security patches, and platform compatibility. This ensures your app remains compliant and continues to work reliably with updates like new mobile OS versions. Learn best practices for integrating and updating SDKs in your app workflow in Insider One’s android SDK integration guide.

When should I use an SDK instead of custom development?

Use an SDK whenever you want to add complex features quickly and safely, such as analytics, messaging, or payment functionality, without building them from scratch. SDKs save time, reduce risk, and allow you to leverage pre-tested functionality. Check how SDKs can accelerate feature rollout for mobile campaigns in SDK‑X for mobile app messaging.