We keep seeing the same pattern team ships an agent, agent works great in testing, agent gets prompt injected in production within the first week. 73% of production AI deployments showed prompt injection exposure in security audits last year. Most of them had zero defensive layers. Not weak layers zero. So we wrote a practical guide covering the 7 things you should actually do in priority order Day 1 (free, immediate) Harden your system prompt explicit deny lists, not vague "be ...