llms.txt is a machine-readable instruction file that points AI tools, agents, and crawlers toward curated documentation, preferred resources, and usage guidance. It is intended to reduce guessing by telling automation where to look and what content matters most.
In cyber security, that convenience creates trust risk. If an automated workflow treats llms.txt as authoritative, an attacker may try to poison the file, register referenced names, or redirect tools toward unsafe dependencies and pages. That can turn documentation into an input to installation, retrieval, or execution. Defensively, teams should manage llms.txt like sensitive operational content: keep it under change control, review external references, validate any package or download targets, and separate documentation from actions that can deploy or run code.