Building Sentinel: A WAF for AI Agents with Genkit

Sentinel is a security middleware framework for Genkit-powered agents. It intercepts prompts, tool arguments, memory context, and model outputs, then enforces actions (ALLOW, WARN, SANITIZE, BLOCK, REQUIRE_HUMAN_APPROVAL) before risky content reaches sensitive systems. This post explains architecture, implementation details, and the exact engineering tradeoffs used to ship a practical, demo-ready security layer. Problem: Agent Systems Need Input Firewalls LLM agents are exposed t...