## You probably already have one

Shopify generates an agent-instruction surface for every store: a default `/agents.md`, with `/llms.txt` and `/llms-full.txt` mirrored from it (as of May 2026). Check yours right now — open `https://your-store.com/llms.txt`. If you've never touched it, you're serving Shopify's default.

That default is generic by design. The question isn't "how do I add llms.txt to Shopify" — it's "should I replace the stock one," and usually yes: the default can't know which collections matter, what your return policy highlights should be, or that your [MCP endpoint](/kb/mcp) exists.

## How the template system works

Per Shopify's theme docs, three Liquid templates control the three paths, with a fallback chain:

1. `templates/llms.txt.liquid` — controls `/llms.txt` only
2. `templates/agents.md.liquid` — controls `/agents.md` *and* is the default source for the other paths
3. No templates → Shopify's generated default

So the leverage point is `agents.md.liquid`: customize it once and all three surfaces inherit, or split `llms.txt.liquid` out separately if you want the index and the instructions to diverge (see [AGENTS.md vs llms.txt](/kb/agents-md-vs-llms-txt) for why you might).

## Customizing it

In your theme editor (Online Store → Themes → Edit code → Templates), add `llms.txt.liquid`:

```
# {{ shop.name }}

> {{ shop.description }}

## Key pages
- [Best sellers](/collections/best-sellers): our most-bought products
- [Shipping & returns](/policies/shipping-policy): what agents should quote customers

## Machine-readable surfaces
- [Product feed](/products.json): live catalog with prices
```

Liquid objects work as in any template, so the file can stay current automatically — loop collections, inject policies, reference metafields.

## What to include

The highest-value lines for agents: your top collections with one-line descriptions, policy pages (shipping, returns — what an agent quotes a customer), and cross-references to machine surfaces (`/products.json`, any [OpenAPI spec](/kb/openapi) or MCP endpoint). Skip marketing prose — agents want structure, not slogans. Full format guidance: [the llms.txt guide](/kb/llms-txt).

## Validate it

Run your store through [the llms.txt validator](/tools/llms-txt-validator) — it checks the file exists, parses, and gives agents navigable structure — or [scan the whole store](/) to see every agent-facing surface at once.

## FAQ

### Does Shopify generate llms.txt automatically?

Yes — every store serves a default /agents.md, and Shopify manages /llms.txt and /llms-full.txt by mirroring it. You override any of the three with Liquid templates.

### Which template should I edit?

Edit templates/agents.md.liquid to change all three surfaces from one source. Add templates/llms.txt.liquid only if you want the llms.txt index to differ from the agents.md instructions.

### Will editing llms.txt affect my Google rankings?

No — Google has documented that Search doesn't use llms.txt either way. Its value is for agents reading your store, not for rankings. See [Does llms.txt actually work?](/kb/does-llms-txt-work)

## Related

- [llms.txt — the full guide](/kb/llms-txt)
- [AGENTS.md vs llms.txt](/kb/agents-md-vs-llms-txt)
- [llms.txt for WordPress](/kb/llms-txt-for-wordpress) · [llms.txt for Next.js](/kb/llms-txt-for-nextjs)