---
title: "llms.txt: Definition"
description: "A proposed convention: a Markdown file at a site's root that summarises the site and links to clean, LLM-readable content for AI agents and tools."
canonical: https://sudosapient.si/terms/llms-txt
updated: 2026-10-27
publisher: Sudo Sapient (https://sudosapient.com/)
---
# llms.txt

**llms.txt:** A proposed convention: a Markdown file at a site's root that summarises the site and links to clean, LLM-readable content for AI agents and tools.

## Why it matters

Adoption by AI companies is unconfirmed, and several site owners report that their llms.txt files receive almost no requests. It is cheap to publish and helps any agent or developer that does look for it. This site publishes a root llms.txt, one per section and an llms-full.txt, and logs how often each is fetched.

## Related terms

- [Answer engine optimisation (AEO)](https://sudosapient.si/terms/aeo): Structuring content and entity information so AI answer engines such as ChatGPT search, Perplexity, Gemini and Google AI Overviews can retrieve, understand and cite it.
- [Model Context Protocol (MCP)](https://sudosapient.si/terms/mcp): An open protocol that standardises how AI applications connect to external tools and data sources through MCP servers exposing tools, resources and prompts.

## In practice

This hub is a live test of it. The tactics, metrics and results are in the [experiment register](https://sudosapient.si/lab/experiments).