When we run a Shopify store through the AI readiness part of our audit, two files come up almost every time, and almost no store has either of them. One is llms.txt. The other is agents.md. Owners usually ask the same thing: is that a problem?
The honest answer is that it's a small one, and it's rarely the first thing to fix. These files are worth adding. They're just not where AI visibility is won or lost today. So before you spend an afternoon writing one, it helps to know what each file really is, what it does, and what it doesn't.
Some context on why we care about this at all. As a Shopify Plus Partner, we build and audit stores, and a real share of our clients' buyers now start a purchase inside ChatGPT, Perplexity or Google's AI Overviews instead of a normal search. That's why we added AI and agentic checks to our store audit in the first place. These two files are part of that picture, but only part.
What llms.txt actually is
llms.txt is a plain Markdown file you place at the root of your domain, at yourstore.com/llms.txt. It gives large language models a clean, curated map of your most important content: a short description of the business, then links to the pages you most want an AI to understand, such as key collections, flagship products, shipping and returns, and contact details.
It was proposed by Jeremy Howard of Answer.AI in September 2024. That origin matters, because it tells you the status: llms.txt is a community proposal, not an official standard. OpenAI, Google and Anthropic have not committed to reading it as a ranking or crawling instruction. Some tools and sites have adopted it. Many haven't. So treat it as a sensible, low-cost bet on where things are heading, not as a switch that changes how ChatGPT sees you tomorrow.
What agents.md is
agents.md is a related idea, and it's earlier still. It's a Markdown file aimed at AI agents rather than human readers or search crawlers. The convention started in the world of AI coding assistants, where agents.md tells an agent how to work inside a codebase, and it's now spreading to websites as a place to tell AI shopping agents who you are and how to interact with your store.
For a Shopify store, that could mean a short note on what you sell, where an agent can find products and prices, and where your policies live. Useful in principle. Just understand that adoption is thin right now, so this is a forward-looking addition, not a fix for a problem you have this quarter.
Adding llms.txt and agents.md is cheap and sensible. But if your robots.txt is blocking OAI-SearchBot, you’re invisible inside ChatGPT no matter what else you publish.
Check your crawlers before you write new files
Here's the part most "AI readiness" advice skips. The single biggest lever for AI search visibility today isn't a new file. It's what your existing robots.txt already allows. A few crawlers are worth knowing by name, because they aren't interchangeable.
- OAI-SearchBot is the crawler behind ChatGPT's search answers. If your robots.txt blocks it, your store can't appear when ChatGPT answers a shopping question. This is the one that actually affects whether you show up.
- GPTBot is OpenAI's training crawler. Blocking it decides whether your content can be used to train models. It does not control whether ChatGPT can surface you in search. So blocking GPTBot while allowing OAI-SearchBot is a perfectly reasonable position, and a common one.
- PerplexityBot does the same job for Perplexity, and Google-Extended is Google's control for its AI training. Each is a separate decision.
Most Shopify stores never touch robots.txt and are fine. The trouble starts when someone adds a blanket rule, or installs an app that writes broad disallow directives, and quietly shuts out the AI search crawlers along with the bad bots. We've seen stores publish beautiful content and then block the exact crawler that would have shown it in ChatGPT. Check this first.
Structured data is the real foundation
The second thing that outranks any discovery file is machine-readable product data. An AI assistant can only recommend a product it can read as a product, which means valid Product structured data with price, availability and, where they're genuine, reviews. If an AI can't parse your prices and stock, no llms.txt will save the recommendation. We go deeper on this in why your store isn't showing up in ChatGPT or Perplexity.
So the order of operations is simple. First, make sure you aren't blocking the AI search crawlers. Second, get your structured data clean. Then, as the forward-looking layer, add llms.txt and agents.md.
How to add these on Shopify
Shopify doesn't give you a built-in field for llms.txt or agents.md, so you serve them yourself. The common routes are a custom page or template that outputs the file at the right path, or a small app that handles it. For robots.txt, Shopify is more generous: on Online Store 2.0 themes you can edit a robots.txt.liquid file and adjust the directives directly, which is where you'd confirm your position on OAI-SearchBot, GPTBot and the rest.
When you do write an llms.txt, keep it short and current. A sentence or two on what the store is, then links to your main collections, a few best-selling products, your shipping and returns policy, and a contact page. Don't list everything. The point is a clean signal, not a second sitemap. For agents.md, write it for an agent trying to help someone buy: what you sell, how to find products and prices, and where your policies are.
How to check where you stand
You can verify all of this by hand. Open yourstore.com/robots.txt and read the user-agent rules. Check whether /llms.txt and /agents.md return a file or a 404. Validate your Product structured data in Google's Rich Results Test.
Or run the shortcut. Our free Shopify store audit has an AI and agentic readiness section that checks exactly these signals: whether agents.md and llms.txt exist, what your robots.txt says to OAI-SearchBot and GPTBot, whether your sitemap and product data are machine-readable, and it scores all of it with no Shopify login required. If you want the wider picture too, the same audit covers the technical SEO basics in our Shopify SEO audit checklist.
So, do you need an llms.txt and an agents.md? Add them. They cost an afternoon and they age well. Just do them in the right order, after you've confirmed you aren't blocking the crawlers that feed AI search and that your products are readable as products. Get that sequence right and the new files become a genuine edge instead of a box you ticked.