AI Product Index / agent card at /.well-known/agent-card.json
It is what turns a page into a tool: a machine-readable statement of what you can be asked to do. The path moved in A2A 1.0, and a card only at the old location is invisible to a compliant client.
Publish an agent card at /.well-known/agent-card.json describing your callable interfaces (A2A 1.0) — this is what turns a page into a tool. Serve the same document at /.well-known/agent.json too, for clients written before the path moved.
{
"_comment": "publish at {{ORIGIN}}/.well-known/agent-card.json (A2A 1.0), and at {{ORIGIN}}/.well-known/agent.json for pre-0.3 clients",
"name": "Your Product",
"description": "One sentence on what it does.",
"url": "{{ORIGIN}}/",
"provider": { "organization": "Your Company", "url": "{{ORIGIN}}/" },
"version": "1.0.0",
"capabilities": { "streaming": false },
"defaultInputModes": ["text/plain"],
"defaultOutputModes": ["application/json"],
"skills": [{
"id": "example",
"name": "Example skill",
"description": "What an agent can ask this service to do.",
"tags": ["example"]
}]
}
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.