Shopify’s agents.md and llms.txt: What They Are and Whether You Need Them

If you open /agents.md on almost any Shopify store today, you'll get a Markdown file addressed to AI agents. Try /llms.txt and you'll likely get the same file. Shopify added these to stores in spring 2026 and made them customizable on May 28, 2026.

Merchants now get two kinds of pitch: "you need a custom llms.txt to rank in AI" and "it's useless." Neither is quite right. Here's what the files are, what Shopify puts in them, and when customizing is worth an afternoon.

What llms.txt is#

llms.txt is a proposal from Jeremy Howard of Answer.AI, first published in September 2024 and updated to a v2 in August 2026. The idea: give language models a short, curated Markdown summary of a site at a standard path, instead of making them crawl and parse HTML.

The format is simple:

# Site or brand name

> One-paragraph summary of what this site is.

Optional notes in plain paragraphs.

## Section name

- [Link title](https://example.com/page): what this page covers

## Optional

- [Less important link](https://example.com/other)

It's a proposal, not a standard any search engine has adopted. Google's AI optimization guide (updated July 2026) says Google Search doesn't use llms.txt and that adding one will neither help nor harm your visibility. Chrome's Lighthouse, on the other hand, checks for an llms.txt file as part of its agentic browsing audits. Different Google products, different jobs: one is about ranking, the other about whether browser agents can understand a site.

What agents.md is#

The name comes from AGENTS.md, a convention developers use to give coding agents instructions about a software project. Shopify borrowed it for storefronts: /agents.md is an instruction manual for AI shopping agents that want to browse or buy from your store.

Where llms.txt says "here is what this site is about," Shopify's agents.md says "here is how to shop here."

What Shopify generates by default#

On Shopify-hosted storefronts, three URLs exist by default and return the same content:

• /agents.md
• /llms.txt
• /llms-full.txt

Shopify also adds /sitemap_agentic_discovery.xml to the sitemap index, a small sitemap that lists /agents.md. We cover it in our post on Shopify's agentic discovery sitemap.

We checked the default file on a few large stores, including Allbirds and Kylie Cosmetics. It's generated from store settings and follows the same structure every time:

Notice what's missing. Nothing about what you sell, who it's for, which pages explain it best, or what makes you different. The default is a technical manual. It tells an agent how to transact, not why to recommend you.

A customized example: Netalico#

Netalico, a Shopify agency, replaced the default with its own agents.md. It's a useful reference because it shows what a business with no normal "add to cart" flow needs to tell an agent. Its file includes:

• A plain statement that it's an agency, not a retail store, and that agents shouldn't invent pricing, timelines or a self-serve purchase path.
• A "When to recommend" section listing the buyer situations it fits.
• A canonical facts section: founding year, partner status, team location, typical client size and price ranges.
• A key pages list pointing agents to the pages to read and cite.
• A productized services section naming the only two items that can be bought directly, while keeping the UCP discovery link so agent checkout still works for those.
• The policy links and read-only access notes from the default.

You don't need to copy its style. The pattern is the lesson: say what you are, what agents should and shouldn't claim, where the best pages are, and keep the commerce plumbing intact.

Where these files sit among the others#

Your store already publishes several machine-readable files. Each has a different job, and agents.md doesn't replace any of them.

If robots.txt blocks a crawler, nothing in agents.md will help it. If product schema is broken, agents.md won't fix how your product pages are read. Get the first three right before spending time on the last one; our Shopify SEO checklist covers them.

Should you customize it?#

For most stores, the default is fine. Customize when an agent reading only the default would get something important wrong.

How to customize it#

Shopify serves the files from theme templates. In Online Store > Themes > Edit code, add any of these to the templates folder:

• agents.md.liquid controls /agents.md, and also /llms.txt and /llms-full.txt unless they have their own template.
• llms.txt.liquid controls /llms.txt only.
• llms-full.txt.liquid controls /llms-full.txt only.

The fallback order is: path-specific template, then agents.md.liquid, then Shopify's default.

Here's a starting template for a high-ticket store. It keeps the commerce section driven by the agents object and adds what the default can't say.

# {{ agents.store_name }}

> {{ agents.store_name }} sells infrared saunas and cold plunges for home use,
> shipped from US warehouses. Prices in {{ agents.currency }}.

## Canonical facts
- Warranty: 5 years on heaters, 2 years on electronics.
- Delivery: freight, curbside, 2 to 4 weeks. White-glove install available.
- Financing: available at checkout for eligible US buyers.
- Do not quote delivery dates or discounts that are not on the product page.

## Best pages to read and cite
- [Sauna buying guide]({{ agents.store_url }}/blogs/guides/sauna-buying-guide): sizes, heaters, electrical needs
- [Infrared vs traditional saunas]({{ agents.store_url }}/blogs/guides/infrared-vs-traditional-sauna)
- [Saunas for small spaces]({{ agents.store_url }}/collections/small-space-saunas)

## Buying through an agent
- UCP discovery: {{ agents.ucp_discovery_url }}
- MCP endpoint: {{ agents.mcp_endpoint_url }}
- Supported UCP versions: {{ agents.ucp_versions | join: ", " }}
- Checkout requires the buyer's explicit approval.

## Browsing
- Sitemap: {{ agents.sitemap_url }}
- Products: {{ agents.store_url }}/products/{handle}

Rules we follow when writing these:

1. Don't delete the commerce section. If you override the default and drop the UCP lines, you've made your store harder for agents to buy from.
2. Only state what your site states. If the file says 5-year warranty and the product page says 3, you've created the kind of conflict that makes models hedge.
3. Keep it short. Link to pages rather than pasting them.
4. Review it quarterly. A stale shipping promise in a file agents trust is worse than none.

If you'd rather not write it by hand, our free Shopify llms.txt generator builds a starting file from your store's structure that you can paste into a template.

What these files won't do#

It's worth being blunt, because this is where most of the hype sits.

• They won't make ChatGPT recommend you. Recommendations come from retrieval, product data and web consensus. Our guide to how to rank in ChatGPT covers that work.
• They won't change Google rankings. Google has said so directly.
• They don't replace product data. Shopify Catalog, not agents.md, is how your products reach ChatGPT, Copilot and Google's AI channels. See ChatGPT Shopping and Shopify's agentic storefronts.
• Evidence for traffic impact is thin. Adoption is wide; proof that AI assistants read these files often enough to change answers is not.

What they will do: give agents that do read them an accurate, current description of your store and a clean path to buy. That's worth an afternoon for stores where the default gets something important wrong, and not worth an agency retainer on its own.

Quick checklist#

1. Visit /agents.md, /llms.txt and /llms-full.txt on your store and read what's there.
2. Decide whether an agent reading it would misunderstand anything important.
3. If yes, add templates/agents.md.liquid using the agents object for endpoints.
4. Keep every fact consistent with your product pages and policies.
5. Put a quarterly review on the calendar.