Recursive Shield
Built at AI Engineer World's Fair Hackathon 2026 · Jun 27, 2026 · San Francisco, CA
Recursive Shield protects browser-use AI agents from audio prompt-injection attacks during sensitive workflows. We built a fake paper-brokerage environment where Gemini listens to market audio and controls tools like read_portfolio, set_field, place_order, and confirm_order. Poisoned audio can subtly steer the agent into unsafe actions such as copying private portfolio data into notes or attempting unauthorized trades. Recursive Shield sits at the tool boundary, evaluates each proposed action against policy, and blocks unsafe behavior before state changes occur. The system also produces labeled trace JSONs for evaluation, guardrail testing, and recursive training.