What is llms.txt, and why your help center needs one

When a customer asks an AI assistant "how do I cancel my Acme subscription?", the assistant has to find your help article, read it, and summarise it correctly. Help center pages are full of navigation, cookie banners and scripts; the actual answer is a small part of the page.

llms.txt is a proposal (llmstxt.org) for making that easy: a plain Markdown file at the root of your site that lists your most useful pages, with a short description of each, pointing to clean Markdown versions of the content.

What an llms.txt file looks like

# Acme Help Center

> Answers to common questions about Acme: accounts, billing,
> integrations and troubleshooting.

## Billing

- [How to cancel your subscription](https://help.acme.com/a/cancel.md): Cancel any time from Billing; annual plans are refunded pro rata.
- [Update your payment method](https://help.acme.com/a/payment-method.md): Add or replace a card in the billing portal.

## Integrations

- [Connect Slack](https://help.acme.com/a/slack.md): Get notifications in any channel.

The format is simple:

1. An H1 with the name of the site (required).
2. A blockquote with a one-paragraph summary.
3. H2 sections with lists of links, each with an optional : description.
4. Optionally, a section named Optional for links that can be skipped when context is short.

Many sites also publish llms-full.txt with the full text of every page in one file.

Why help centers benefit the most

• Questions are the content. Help articles are already short, self-contained answers — exactly what an assistant needs.
• Accuracy matters. An assistant that misreads your refund policy creates a support ticket (or a chargeback). Clean Markdown reduces misreadings.
• It is cheap. The file is generated from content you already have.

How to add one

You can write the file by hand, but it goes stale the moment you add an article. Generate it whenever your help center is published instead.

On kbshelf this happens automatically: every publish writes llms.txt, llms-full.txt and a .md version of each article, grouped by your categories.

Check yours

Use our free llms.txt checker to validate the structure of any site's llms.txt: required title, summary, sections, link format, and whether the linked pages actually load.