This is a simple single-file python program that can find basic XSS (cross-site scripting) vulnerabilities in a target url. Most XSS discovery tools use a payload refelection strategy in which payloads are injected in url parameters and the GET response is inspected for places where the payload content is reflected. This is a very low precision XSS detection strategy because most reflection does not support execution.

This program uses a different approach, and instead opens the target url in a browser, tests alert(...) payloads directly in the browser context, and listens for an alert being triggered. This means that any XSS spotted by this program is extremely unlikely to be a false positive.