AI
llms.txt
llms.txt is a markdown file served at a site's root that provides language models with a concise, curated index of the site's most useful content, including links to clean text versions of key pages.
Where robots.txt tells crawlers what they may not access, llms.txt tells AI systems what is worth reading and how the site is organised: a positive rather than restrictive signal.
A companion llms-full.txt typically contains expanded content inline, so a model can ingest substantive material without fetching many separate pages.
Adoption remains voluntary and unenforced, but the cost of publishing one is trivial relative to the potential citation benefit.
See also