Where a link actually goes — every redirect hop, not just the destination — what the server says about itself, and the pages a site publishes. Pay-per-call in USDC on Base (x402 v1+v2).
| Endpoint | Price | What it returns |
|---|---|---|
| /resolve?url=https://bit.ly/example | $0.001 | Every redirect hop, final URL, tracking params stripped |
| /headers?url=https://example.com | $0.001 | Status, server, caching, security headers set/missing |
| /sitemap?url=https://example.com | $0.002 | Pages the site publishes, with last-modified dates |
Payment: send an X-PAYMENT header. Free: /health, /sources, /llms.txt, /openapi.json. Security-header presence is a hygiene signal, not a safety verdict. An unreachable host is not charged.