Guardrails AI is an platform that wraps around Large Language Models (LLMs) to enhance their reliability and trustworthiness through modular components called "validators." These validators act as programmable checkpoints that monitor and verify LLM outputs for specific behaviors, compliance requirements, and performance metrics. Through their Guardrails Hub marketplace, organizations can deploy pre-built validators or customize their own to enforce specific rules and policies, effectively creating a safety layer that helps detect and mitigate issues like hallucinations, policy violations, and unauthorized data exposure.