What is llms.txt, and should a dive center have one?

Every dive center website has a robots.txt — the file that tells search engines which pages they may visit. llms.txt is the newer cousin: a plain-text page, written in Markdown, that tells an AI assistant what your site is about and where to find the things that matter. Think of it as the summary you’d give a new instructor on their first day, written for a machine.

What goes in it

The format is deliberately simple. A heading with your name, a one-line description, then short sections with links and a sentence of context for each:

# Coral Bay Divers
> PADI 5 Star Dive Center in Utila, Honduras. Courses, fun dives, live availability.

## Courses and prices
- [Open Water Diver](/courses/open-water): 3 days, from $420, groups of 4 or fewer
- [Advanced Open Water](/courses/advanced): 2 days, from $350

## Practical
- [Live availability](/products/availability.json): updated every 15 minutes
- [Safety and policies](/safety): insurance, emergency oxygen, cancellation terms

That’s the whole idea. An assistant that reads this knows what you sell, roughly what it costs, and where to look for the current answer — without crawling forty pages and guessing which one is the price list.

What it isn’t

llms.txt does not make you rank. It does not replace structured data (the schema.org markup on each page that says “this is a Course, this is its price”). And it does nothing if the pages it points to are out of date. It’s a table of contents, not a strategy.

It’s also not yet a standard every assistant reads. Adoption is uneven and changes month to month. The reason to have one anyway is cost: it takes an hour to write, nothing to host, and it’s the first thing an agent looks for when someone asks “does this site have a summary I can trust?”

Three things to get right

1. Prices in the file, not just links to them. An assistant reading “from $420” can answer a question; one reading “see our courses page” has to keep digging, and may give up.
2. Point at things that are current. If your availability lives in a booking system, link the feed, not a page that says “contact us”.
3. Keep it consistent with your pages. If llms.txt says $420 and the course page says $450, the assistant now has two answers and trusts neither.

What Terasano does

Every Terasano site generates its llms.txt from the same content model as the pages themselves, so the summary and the pages can’t disagree. When a price changes in chat, the file changes with it. You can read this site’s own at /llms.txt.