llms.txt: a proposed standard no major AI platform has confirmed it uses

A 2026 SE Ranking analysis of 300,000 domains showed 10.13% host an llms.txt file, and only one of the top fifty AI-cited sites includes it. Google’s Gary Illyes confirmed the search engine does not support llms.txt, and no major AI provider has pledged to use it. The file can be generated in roughly twenty minutes, formatted as a Markdown list at /llms.txt with ten-to-forty key pages and one-sentence descriptions, served as text/plain, and kept current to aid agentic routing, surface content gaps, and business-to-agent interactions.