Htcap is a web application analysis tool for detecting communications between javascript and the server. It crawls the target application and maps ajax calls, dynamically inserted scripts, websockets calls, dynamically loaded resources and some interesting elements. The generated report is meant to be a good starting point for a manual web application security audit. Htcap is written in python and uses phantomjs to load pages injecting a probe that analyzes javascript behaviour. Once injected, the probe, overrides native javascript methods in order to intercept communications and DOM changes. It also simulates user interaction by firing all attached events and by filling html inputs.