Securing AI Agents [at Uber]: Lessons from Real-World Deployment

Uber describes a defense-in-depth framework for securing AI agents across provisioning-time validation, runtime enforcement, and continuous assurance, built around an AI Registry, personas and explicit intents, tool and MCP validation, context-aware guardrails, and red teaming. At runtime, AI Guard acts as a policy decision point using small locally hosted models, while prompt provenance and evidence chaining correlate privileged actions back to what the user actually requested. The post also covers tradeoffs around false blocks, latency, and developer adoption, and argues that restricting agents to explicit intents and constraints was the most effective mitigation.