How do you get traffic from ChatGPT and Perplexity? Probably the most common question of the past year — and the Shopify App Store has answers ready. "Generate llms.txt." "Get cited by AI search." "Rank on ChatGPT." Prices run from free to $299 a month.

Three pieces of primary-source information are worth checking before you pay.

One. Shopify already serves /agents.md, /llms.txt, and /llms-full.txt on every store. The help center says, in as many words, that you don't need a third-party app to generate these files.

Two. Google's documentation says Google Search ignores llms.txt. Its changelog puts it as: these files aren't needed for Google Search and won't negatively or positively impact your visibility or rankings.

Three. OpenAI, Anthropic, and Perplexity make no mention of reading anyone else's llms.txt in their official crawler documentation. All three point to robots.txt as the control surface.

Below: what Shopify ships natively, and what in the GEO/AEO app category is and isn't worth money — sourced entirely from official documentation. Research date: September 1, 2026.

The short version

Don't install an app just to generate llms.txt. Shopify serves it already, and if you want different contents you add a theme template from the admin.

AI-driven product exposure is also on by default. Shopify Catalog and agentic storefronts are enabled by default for eligible stores, with ChatGPT, Google AI Mode / Gemini (early access), Microsoft Copilot, and Meta named as channels. This isn't something an app switches on.

Where these apps might earn money is measurement, not generation. Tracking which prompts surface your store is not something Shopify offers natively. But that's visibility into the current state — not a mechanism for improving rank.

And "rank on AI search" claims have no verifiable basis. With Google itself telling site owners to prioritize effective SEO over "AEO/GEO hacks," that pitch is a poor reason to choose an app.

What Shopify already gives you

/agents.md and /llms.txt are served automatically

Shopify's help center page on agentic storefronts states that every Shopify store automatically serves discovery URLs that AI agents can read to learn how the store works. There are three:

• /agents.md — the canonical agent discovery URL
• /llms.txt — for older AI crawlers that look for that specific convention
• /llms-full.txt — same

By default all three return the same content: store name, store URL, sitemap link, store policies, and discovery endpoints. And on that same page: "You don't need a third-party app to generate these files."

You can customize them from the admin

You aren't stuck with the default. Under Online Store → Edit code, add a new template named agents.md, llms.txt, or llms-full.txt and you override the output. The lookup order for /llms.txt is llms.txt.liquid, then agents.md.liquid, then Shopify's generated default.

One caveat: agents.md.liquid runs in a restricted Liquid context. Only request and agents are available — shop, articles, blogs, collections, pages, and linklists are not injected and come back empty. The agents object exposes store name, store URL, UCP discovery URL, MCP endpoint URL, supported UCP versions, currency, and sitemap URL.

So "write my whole catalog into llms.txt" isn't something the native template can do. That's a real functional difference an app could fill — subject to the caveat in the next section about whether anything reads it.

Shopify Catalog and agentic storefronts

Product data reaches AI channels by a separate route from llms.txt. Shopify Catalog is a structured product information source that eligible products enter automatically, and the help center states that you can't opt out of Shopify Catalog itself. You can disable access for individual agentic storefronts, and to hide a product entirely you set its status to Unlisted.

The same page carries this caveat:

Being included in Shopify Catalog doesn't guarantee that a product will appear in a specific AI answer, be ranked in a specific position, or be displayed by every channel.

There's no mechanism by which a third-party app could guarantee what Shopify itself declines to.

What Google and the AI companies actually say

Google

Google's guide to optimizing for generative AI search includes a section on what you don't need to do, and llms.txt is named in it: you don't need to create machine-readable files, AI text files, markup, or Markdown to appear in Google Search including its generative AI features, because Google Search itself doesn't use them.

Google's Search Central changelog entry of June 15, 2026 states the position compactly — these files aren't needed for Google Search and won't negatively or positively impact your visibility or rankings, though it's fine to maintain them for other services that use them.

The summary section tells site owners to prioritize effective SEO over "AEO/GEO hacks," naming content "chunking" and creating unnecessary AI text files such as llms.txt.

Google's position is unambiguous: llms.txt is harmless and it does nothing for Google Search.

OpenAI, Anthropic, and Perplexity

We checked all three sets of official crawler documentation.

OpenAI documents four crawlers — OAI-SearchBot, OAI-AdsBot, GPTBot, and ChatGPT-User — and the only controls described are robots.txt and allowing its published IP ranges. To appear in search results it recommends allowing OAI-SearchBot in robots.txt. No mention of reading llms.txt.

Anthropic documents ClaudeBot, Claude-User, and Claude-SearchBot, and states its bots honor industry-standard robots.txt directives. No mention of llms.txt.

Perplexity documents PerplexityBot and Perplexity-User, with robots.txt and WAF-based controls. No mention of llms.txt.

Worth separating: OpenAI and Perplexity both publish llms.txt files for their own documentation sites. That's a fact about what they publish, not a statement that they read yours. The two get conflated constantly.

What the proposal's authors say

The current version of the llms.txt specification at llmstxt.org (v2, updated August 10, 2026) draws this distinction with robots.txt: robots.txt tells automated tools what access is acceptable, while llms.txt information is used on demand, when an agent needs information about a topic while assisting a user.

The authors describe the intended use as inference-time reference rather than training. Platforms listed as generating the file automatically include Mintlify, GitBook, Yoast SEO, AIOSEO, and Wix. Shopify is not among them — Shopify went its own way, making /agents.md the canonical URL rather than adopting the proposal's framing.

Five GEO/AEO apps compared

Verified on the Shopify App Store on September 1, 2026.

App	Developer	Rating (reviews)	Built for Shopify	Launched	Free plan	Cheapest paid	Top tier	Japanese UI
Avada AEO SEO Optimizer LLMs	Avada SEO Suite	5.0 (352)	Yes	2025-07-31	Free (no paid tiers)	—	—	No
FSEO : ChatGPT SEO + LLMs.txt	Final Apps	4.1 (12)	Yes	2025-10-23	Yes	$29/mo	$299/mo	No
Comergent AEO Agentic Commerce	Comergent AI PTE LTD	4.4 (7)	Yes	2025-04-07	Free to install + usage	$1 per credit	Not listed	No
Smart LLMS.txt Generator	EasycodingSchool	3.3 (3)	No	2025-07-31	Free only	—	—	No
IFG GEO Optimizer: AI SEO/AEO	IFG eCommerce	0.0 (0)	No	2026-08-06	Yes	$12.99/mo	$24.99/mo	Yes

Three observations.

The launch dates tell you this is a young category. The oldest, Comergent, dates to April 2025. IFG GEO Optimizer launched in August 2026 and has zero reviews. You can't select on long-run operating history here.

All five pitch llms.txt generation, which duplicates Shopify's native output. Avada's review section carries a note dated June 13, 2026 from an Australian store: with Shopify's recent agentic changes, the llms.txt this app creates is now redundant, because Shopify uses agents.md. That's a five-star review making the point, which makes it more interesting, not less. Elsewhere in the same review section, the developer's own reply to another merchant explains that the app now uses Shopify's native llms.txt — the vendor acknowledging the overlap.

Price differences don't track feature differences. Avada is entirely free with a 5.0 rating across 352 reviews, while FSEO's top tier is $299 a month. The delta is mostly AI citation tracking volume (3 prompts on Free up to 350 on Growth) and channel coverage. llms.txt generation itself is available free, or from Shopify directly.

FSEO's reviews also include a one-star entry dated June 12, 2026 from a US store reporting that it went from ranking in ChatGPT before installing to not getting a single ChatGPT ranking afterward. A single review establishes no causation, but it does illustrate that nothing in this category can promise an outcome.

What might still be worth paying for

Two capabilities here genuinely don't exist natively.

AI citation tracking records, over time, whether ChatGPT or Gemini names your store in response to prompts you specify. Shopify has nothing equivalent. As a way to see where you stand — rather than a lever to change it — the cost can make sense. FSEO tracks 3 prompts on its free tier; IFG GEO Optimizer covers 5 to 15 prompts a month on Grow and above.

AI crawler simulation is also absent natively. IFG GEO Optimizer advertises rendering your pages as they'd appear without JavaScript execution. If your theme relies on JavaScript to paint product information, this surfaces the possibility that crawlers never see your copy. That's a classic crawlability problem rather than an AI-specific one, and fixing it helps SEO generally.

What shouldn't drive the decision:

• llms.txt generation itself (Shopify already provides it)
• "Rank on AI search" or "get to the top" claims (Shopify doesn't guarantee this either)
• FAQ schema or rich snippets (Google retired FAQ rich results on May 7, 2026)

If you want to block AI crawlers instead

The opposite request comes up too. Shopify describes two layers.

Bot management at the network layer is handled by Shopify, with no merchant action required. Putting a proxy in front of Shopify isn't recommended and isn't supported.

At the /robots.txt layer, you can allow or block specific user agents by adding a robots.txt.liquid template to your theme. That template isn't included in themes by default — you create it. Shopify notes that robots.txt rules are directional and advisory, and not all crawlers are guaranteed to follow them. The customization is unsupported, and Shopify warns that incorrect use can result in loss of all traffic.

The most important caveat is this one:

Blocking AI crawlers at the /robots.txt or network layer affects only open-web discoverability. It doesn't stop your product data from being sent by Shopify Catalog to the agentic storefronts that you've activated.

robots.txt does not stop Shopify Catalog. To stop that, you disable individual agentic storefronts in settings, or set products to Unlisted.

Pre-install checklist

1. Open /agents.md and /llms.txt on your own domain and read what's already being served.
2. Name specifically what's missing from it. If you can't, you don't need an app.
3. Subtract "llms.txt generation" from an app's pitch and see what's left.
4. If you want citation tracking, compare on tracked prompt count and channel coverage.
5. For any app promising AI search rankings, find where that claim is substantiated.
6. Check your current Shopify Catalog and agentic storefront settings in the admin — they're on by default.
7. If you want to block AI, understand that robots.txt alone won't do it.
8. Check whether your theme paints product information via JavaScript. Fix that as a standard SEO issue.

Wrapping up

Three steps.

1. Open your own /agents.md first. Every Shopify store already serves it. Decide what's missing after looking at the real thing. Shopify's help center says outright that a third-party app isn't needed.

2. Separate generation from measurement. There's no reason to pay for llms.txt generation. Citation tracking and crawler simulation aren't native, so they're at least worth evaluating.

3. Fold Google's stated position into your criteria. "Google Search ignores them" and "prioritize effective SEO over AEO/GEO hacks" are Google's own words. None of this argues against caring about AI search — but it is not a game where dropping one file in your root increases traffic.

Official documentation and Shopify App Store listings were checked on September 1, 2026. This area moves quickly; verify current details before installing.