{"service":"diffbeacon","version":"0.1.0","what":"Semantic web-change monitoring for AI agents: give it a URL, get a webhook when the page's meaning changes — not when a timestamp or an ad rotates.","how":"BGE-M3 embeddings (Cloudflare Workers AI) + cosine similarity + word-level diff. Ignores layout churn, catches real content changes.","pricing":{"free_tier":"5 watches without an account, 60-minute minimum checks, POST /waitlist for 5 watches","pro":"$9.00/month USDC (x402, Base): 50 watches, 10-minute checks, webhook alerts"},"endpoints":{"POST /watch":"create watch {url, mode?: 'semantic'|'raw', threshold?: 0.985, interval_minutes?: 240, webhook_url?}","GET /watch/:id":"status + last 10 events","DELETE /watch/:id":"stop a watch","GET /watches":"list watches (Authorization: Bearer <api_key>)","POST /subscribe":"pay $9/mo: GET first for the 402 terms, then POST with PAYMENT-SIGNATURE","POST /waitlist":"{email} -> free api_key (5 watches)","GET /whoami":"account status","GET /dashboard":"human view"},"payment":{"protocol":"x402","version":2,"network":"eip155:8453","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","payTo":"0xa1b8be63bde77ddc65d9ffe8a21a2a5f2c9ca6a8"},"dashboard":"/dashboard"}