AI Product Index / machine-readable alternates advertised
It tells an agent that a JSON or Markdown version of this page exists. Without it, a client that would rather parse data than HTML has no way to discover that it can.
Add <link rel="alternate" type="application/json"> (and text/markdown) pointing at machine-readable versions of the page.
<!-- in <head>: point agents at the machine-readable twin of each page -->
<link rel="alternate" type="text/markdown" href="{{ORIGIN}}/llms.txt" title="llms.txt">
<link rel="alternate" type="application/json" href="{{ORIGIN}}/api/index.json" title="JSON API">
<!-- ...and/or as a response header, which agents see without parsing HTML: -->
Link: <{{ORIGIN}}/llms.txt>; rel="alternate"; type="text/markdown"
Free, no signup, same endpoint that produced every grade on the leaderboard:
curl "https://index.percall.dev/api/score?url=https://your-site.example"
It returns the letter grade and every check by name with pass/fail. The
$0.05 call at POST /api/audit adds why each one failed and a
snippet with your origin already in it.