In the rapidly evolving Web3 landscape, passive security (audits) is no longer enough. The recent migration of Kelp DAO to new infrastructures and the rise of protocols like Rhea Finance demand active, real-time protection. Today, I’m sharing my latest work: a Sentinel AI Agent designed to detect and prevent vault invariant deviations before they lead to a loss of funds. The Problem: "Ghost Debt" and Oracle Invariants While auditing DeFi protocols, I've focused on subtle vulnerabilities: rounding errors, invariant deviations, and "ghost debt". For a protocol like Rhea Finance, the critical invariant is the Assets-to-Shares ratio. If this ratio shifts unexpectedly, it’s a sign of a potential exploit. The Solution: A Hybrid Security Stack My approach combines high-speed off-chain monitoring with automated on-chain response: Monitoring Core (Clojure/Leiningen): Chosen for its speed and functional approach to state management.…