llms.txt
Text file at a site's root that lists its key pages in plain language, meant to guide language models rather than classic indexing bots.
Modeled on robots.txt, llms.txt offers a structured list of links and short descriptions, in Markdown, to help a language model read a site during a search or an answer generation.
Adoption remains uneven and no major engine guarantees it will use the file, but it costs little to set up and clarifies the site's structure.