llms.txt is a plain-text file at your site's root that gives AI crawlers and language models a curated map of your most important pages, written in plain language rather than HTML. It works like a robots.txt for meaning instead of permissions — pointing models toward the content you'd most want summarized or cited.
Whether it moves the needle is still genuinely unproven; no major AI vendor has confirmed it directly influences citation. It's cheap to ship and can't hurt, which is why Kando publishes one on kandomarketing.com alongside JSON-LD schema — treat it as good hygiene, not a silver bullet.