A plain-text file at the root of a domain (like /robots.txt) that gives AI systems a curated, machine-readable summary of your brand, products, and key documentation links.
The llms.txt standard was proposed by Jeremy Howard in 2024 and has been adopted by Anthropic, Mistral, and several major SaaS brands. It is a markdown file served at https://yourdomain.com/llms.txt that lists your most important pages, your brand description, and structured links to documentation, pricing, and key resources.
Why it matters: when an AI agent visits your site programmatically, it does not have time to crawl every page. llms.txt gives it a curated map. Brands that ship one are increasingly being cited more often in Perplexity and Claude. VibecodeAEO can audit, generate, and validate llms.txt for you.
Real-world example
Anthropic ships an llms.txt at anthropic.com/llms.txt listing their key pages, API documentation, and brand description — so when Claude is asked about AI safety tools, it has a curated map to follow rather than guessing.
Frequently asked questions
Does my site need an llms.txt file?+
If you want AI agents to accurately represent your brand, yes. Without llms.txt, AI systems must guess which of your pages matter most. With it, you hand them a curated index of your key pages, brand positioning, and documentation — dramatically reducing misrepresentation.
How do I create an llms.txt file?+
Create a markdown file at the root of your domain (yoursite.com/llms.txt). Start with a one-paragraph brand description, then list your most important URLs with one-line descriptions. VibecodeAEO can generate and validate one for your domain automatically.
Does llms.txt improve AI citations immediately?+
For RAG-based engines like Perplexity that crawl live content, improvements can appear within days. For LLM-only engines like ChatGPT and Claude that rely on training data, you will need to wait for the next training update (typically every few months).
Related terms
Answer Engine Optimization (AEO) — The practice of optimizing content, schema, and brand signals so that AI answer engines like ChatGPT, Perplexity, and Gemini cite your brand accurately when answering user queries.
robots.txt — A plain-text file at /robots.txt that tells web crawlers (search engines and AI bots) which pages they may access. Mis-configuring it is the #1 way brands accidentally block themselves from AI engines.
Schema Markup — Standardized JSON-LD or microdata embedded in HTML that tells search engines and AI systems the meaning of page content (e.g., this is a product, this is a FAQ, this is a person).