llms.txt
llms.txt is a proposed plain-text file at the root of a website that summarises what the site is and points to its most important pages for AI systems.
The convention was proposed to give language models a concise, curated entry point to a site — closer in spirit to a hand-written index than to robots.txt, which grants or denies access rather than explaining anything.
Adoption by major engines is not universal and should not be assumed. It is cheap to publish and does no harm, but it is a supplement to clear on-page content and structured data, never a substitute.
Why it matters
It costs almost nothing to add and states plainly what your business is and which pages matter. Treat it as a small hedge on an emerging convention rather than a lever with proven effect.