What is llms.txt?

llms.txt is a proposed standard: a markdown file at /llms.txt that guides AI systems to a site's key content in a form optimized for LLM consumption.

llms.txt is a file placed at the root of a website (the path /llms.txt) written in markdown, proposed by the Answer.AI team in 2024 as a standard way to give AI language models a curated map of a site's most important content. It lists sections and links with short descriptions, similar to robots.txt but for content discovery rather than crawl permissions. An extended variant, llms-full.txt, contains the full text of the linked content. Adoption is voluntary, and the spec at llmstxt.org documents the format and examples; it is one of several mechanisms sites use to make content easy for AI answer engines to retrieve and cite.