Building Sentinel Gate: A 3-Layer Security Pipeline for AI Agents
How I Built a 3-Layer Security Pipeline for My AI Agent in 5 Minutes Your AI agent has API keys, passwords, phone numbers, and email addresses. It also has access to the internet. What could go wro...

Source: DEV Community
How I Built a 3-Layer Security Pipeline for My AI Agent in 5 Minutes Your AI agent has API keys, passwords, phone numbers, and email addresses. It also has access to the internet. What could go wrong? Everything. I run a 10-agent AI system (OpenClaw) on a single MacBook. It posts tweets, sends emails, fetches web pages, and executes shell commands — all autonomously. Last week, I realized I had zero protection against my own agents accidentally leaking secrets or executing injected commands from fetched web content. So I built Sentinel Gate — a 3-layer security pipeline that sits between my agents and the outside world. The Threat Model Three attack surfaces: Outbound leaks — An agent constructs a tweet, email, or API call that accidentally includes an API key, phone number, or password. This is the most common failure mode. All it takes is one careless template. Inbound injection — Web content fetched by an agent contains embedded shell commands or prompt injection. "Ignore previous i