> For the complete documentation index, see [llms.txt](https://dev-angelist.gitbook.io/writeups-and-walkthroughs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev-angelist.gitbook.io/writeups-and-walkthroughs/portswigger-web-security-academy/api-testing.md).

# API Testing

https\://portswigger.net/web-security/api-testing

APIs (Application Programming Interfaces) enable software systems and applications to communicate and share data. API testing is important as vulnerabilities in APIs may undermine core aspects of a website's confidentiality, integrity, and availability.

All dynamic websites are composed of APIs, so classic web vulnerabilities like SQL injection could be classed as API testing. In this topic, we'll teach you how to test APIs that aren't fully used by the website front-end, with a focus on RESTful and JSON APIs. We'll also teach you how to test for server-side parameter pollution vulnerabilities that may impact internal APIs.

#### **Topics**

> 1. [API Testing](/writeups-and-walkthroughs/portswigger-web-security-academy/api-testing.md)
> 2. Server-side parameter pollution