{
 "what": "Webhook for 30 days: after each 6-hourly live re-check, POST the changes it found to your https callback. Scope: one gap list (domains that entered or left it), one domain, or every change on this census (4,961 colleges). Body JSON { callback, list? , domain? }; status at https://colleges.agentexchange.work/watch/<id>.json. Free alternative: the Atom feeds.",
 "method": "POST",
 "url": "https://colleges.agentexchange.work/watch",
 "price_usdc": 1,
 "days": 30,
 "protocol": "x402",
 "network": "eip155:8453",
 "payTo": "0xc91cE6291eDC0713ec753BAFBA002506ffb2b95c",
 "enabled": true,
 "body": {
  "callback": "https://your.host/path (required; https, public DNS name)",
  "list": "one of no-accessibility-link, no-privacy-link, no-security-txt, expired-security-txt, no-hsts, blocks-assistants, http-only, redirects-off-domain (optional)",
  "domain": "a domain of this census (optional); omit both for every change"
 },
 "delivery": {
  "schedule": "after each 6-hourly re-check that finds a matching change",
  "method": "POST",
  "content_type": "application/json",
  "user_agent": "agentexchange-watch/1.0 (+https://colleges.agentexchange.work/watch)",
  "max_per_run": 40,
  "timeout_ms": 5000,
  "body_example": {
   "watch": "<id>",
   "census": "colleges-web-census-2026-09",
   "scope": {
    "kind": "list",
    "list": "<slug>"
   },
   "events": [
    {
     "domain": "example.org",
     "at": "ISO",
     "changes": [
      {
       "field": "hsts",
       "from": false,
       "to": true
      }
     ],
     "list": {
      "slug": "<slug>",
      "moved": "left"
     }
    }
   ]
  }
 },
 "status": "https://colleges.agentexchange.work/watch/<id>.json",
 "free_alternative": {
  "changes_feed": "https://colleges.agentexchange.work/changes.xml",
  "list_feeds": [
   "https://colleges.agentexchange.work/leads/no-accessibility-link.xml",
   "https://colleges.agentexchange.work/leads/no-privacy-link.xml",
   "https://colleges.agentexchange.work/leads/no-security-txt.xml",
   "https://colleges.agentexchange.work/leads/expired-security-txt.xml",
   "https://colleges.agentexchange.work/leads/no-hsts.xml",
   "https://colleges.agentexchange.work/leads/blocks-assistants.xml",
   "https://colleges.agentexchange.work/leads/http-only.xml",
   "https://colleges.agentexchange.work/leads/redirects-off-domain.xml"
  ]
 }
}