# IOI catalog link checker

On-demand, owner-controlled availability checker at /owner/link-checker. It checks a single exact URL already published in IOI's industry or book catalog. Current catalog links are all under https://www.industriesofindia.com. No user-supplied destination outside that allowlist is accepted. No arbitrary fetch proxy, localhost, private networks, URL credentials, fragments or query URLs.

Each run sends one HEAD request with RFC9421 Ed25519 Signature, Signature-Input and Signature-Agent headers. The identity is https://www.industriesofindia.com. Public keys are at /.well-known/http-message-signatures-directory, whose response is also signed. Request signatures cover method,authority,path and signature-agent, expire after60seconds and have a fresh nonce. Receiving services decide whether to trust the key; signed does not mean Cloudflare verified-bot registration or allowlisting. No bot-submission claim is made.

Owner token is kept privately in the vault. It is never embedded in this page. Maximum20checks/hour globally,8second request timeout. No redirect following, retries, downloaded response body, unrelated crawling, periodic schedule or external AI provider. Challenges,403and429 are reported and not retried. The response reports the actual HTTP status rather than hiding a failed check. No site content is changed. No costs, billing upgrades, purchases or search-index submissions.