Discovery
MEDIUMSitemap declared in robots.txt
robots.txt includes at least one `Sitemap:` line pointing at the XML sitemap. Declaring the sitemap in robots.txt is the simplest way to point every crawler at your full product list.
What this check looks for
The sitemaps.org protocol defines a top-level `Sitemap:` directive that advertises the sitemap URL inside robots.txt. Declaring it removes every crawler's need to guess `/sitemap.xml`, supports multiple sitemap files (e.g., sitemap-index + per-section sitemaps), and is the simplest mechanism by which a store says 'here is my catalog.'
Which AI surfaces it affects
- Google AI Mode (UCP)50
- Microsoft Copilot40
- ChatGPT (ACP)20
- Perplexity20
- Meta AI20
Weighted against the live specs — ACP 2026-04-17, UCP 2026-04-08.
How to fix it
Add a `Sitemap:` line to robots.txt
Shopify
A few minutes- Shopify auto-generates `/sitemap.xml` and includes a `Sitemap:` line in the default robots.txt.
- If you've customized templates/robots.txt.liquid, confirm the `Sitemap:` line is still present (the default emits `{{ shop.url }}/sitemap.xml`).
BigCommerce
A few minutes- Storefront → SEO → robots.txt.
- Add `Sitemap: https://yourdomain.com/xmlsitemap.php` at the top of the file.
WooCommerce
A few minutes- Yoast SEO auto-publishes a sitemap and adds a `Sitemap:` line to the generated robots.txt.
- Verify via Yoast SEO → Settings → APIs → XML sitemaps is ON, then refetch /robots.txt to confirm the line is present.
Custom / headless
A few minutes- Add a top-level `Sitemap:` line to robots.txt — outside any `User-agent` block.
User-agent: *
Allow: /
Sitemap: https://yourdomain.com/sitemap.xml
Sitemap: https://yourdomain.com/sitemap-products.xml
The spec it's pinned to
sitemaps.org — Sitemap location
The sitemaps.org protocol allows a robots.txt `Sitemap:` directive to advertise the sitemap URL. Declaring it in robots.txt removes the 'guess /sitemap.xml' step for every crawler that respects the protocol.
Does your store pass this check?
Run the full audit — 82 checks across five AI shopping surfaces. Most tools only check whether you get mentioned; we check whether an agent can buy from you.