Sitemap includes non-content files (assets, scripts, robots.txt)

Context

While fixing a sitemap 500 error on the support site (dnsimple/dnsimple-support#1958), @weppos flagged that both sites should be kept in sync. This issue tracks the equivalent problem on the developer site.

What's wrong

The live sitemap at https://developer.dnsimple.com/sitemap includes non-content files that should not be indexed:

• assets/css/style.css
• assets/images/border.jpg (and 15+ other image files)
• ddns/ddns.sh
• robots.txt
• llms.txt
• v2/openapi.yml
• The sitemap page itself (/sitemap)

These inflate the sitemap with low-value URLs and can signal poor sitemap quality to crawlers.

Additionally, all entries share the same lastmod date (2026-05-25), which reflects the last deploy timestamp rather than actual content changes. Google has said it ignores or distrusts lastmod when it appears inaccurate or uniform across all URLs — which is exactly the case here.

What already exists

lib/default.rb has a sitemap_items helper that's already doing some filtering — it excludes is_hidden items and the /v2/platform/ subtree. The fix builds on that by also excluding items that don't resolve to page URLs.

Suggested fix

In lib/default.rb, update sitemap_items to reject items whose path is nil or doesn't end with / (pages on this site use trailing-slash URLs; assets and files resolve to extensions):

def sitemap_items
  @items.reject do |item|
    item[:is_hidden] ||
      platform_sitemap_excluded?(item.identifier.to_s) ||
      item.path.nil? ||
      !item.path.end_with?('/')
  end
end

This would keep all legitimate content pages (/v2/domains/, /getting-started/, etc.) while excluding CSS, images, scripts, text files, and the sitemap itself.

References

• dnsimple/dnsimple-support#1958 — the support site fix this is paired with
• nanoc XMLSitemap helper docs
• nanoc issue #1082 — documents the recursive dependency failure mode from bare xml_sitemap calls