llms.txt is a simple text file you place on your website that gives AI assistants a clean, plain-text summary of your pages, so they can read your business without wading through layout code. Think of it as a readme written for machines: your key pages, plainly labeled, in the order that matters.
A normal web page is wrapped in design and scripts that a person’s browser sorts out but an assistant has to guess through. A plain copy removes the guessing, so an assistant quotes your real hours and services instead of a hallucination. Almost no one ships one yet: about 1 in 48 sites publishes an AI readme like this (HTTP Archive Web Almanac, 2025). Being early is a genuine, and shrinking, advantage.
It sits alongside a couple of related ideas: markdown negotiation, which serves any single page as clean text on request, and structured facts embedded in the page itself. Together they make a site legible to AI search.
I ship an llms.txt, and a fuller companion file, on every build. An assistant can only quote your business correctly if it can read a clean copy of it. This is part of the agent readiness groundwork included in a build.