OnTrack: Real-Time Monitoring and Intervention in LLM Agent Trajectories via Streaming Structure-Aware Optimal Transport
This solves a real deployment problem: catching agent errors before they're irreversible, and doing it with sub-millisecond latency so you don't tank performance. The technical trick is using optimal transport to compare trajectories without full reference data. If you're running any LLM agent in production that can take costly or dangerous actions—trading, infrastructure automation, customer-facing decisions—this is the safety guard you should build or deploy. The paper covers three regimes with degrading information access, which is practical.