The Answer Economy needs a new contract
For twenty years, robots.txt told search crawlers what to index. That contract was built for a web of blue links. In the Answer Economy — where ChatGPT, Claude, Perplexity and Gemini synthesize answers directly — we need a new file: llms.txt.
llms.txt is a plain-Markdown manifest you place at the root of your domain. It gives large language models a concise, machine-readable summary of what your site is about, who you are, and which URLs contain your most citable content.
Why it matters now
AI engines have limited context windows. When a model decides whether to cite your page in an answer, it leans on whatever signal it can parse cheaply. A well-structured llms.txt shortcuts that decision: it surfaces your authority statement, your canonical pages, and your topical clusters in a format optimized for tokens, not pixels.
Sites that ship llms.txt early are doing the same thing successful SEO operators did in 2004 with XML sitemaps — claiming territory before the standard becomes table stakes.