CTlogs.io

CTlogs.io gives Claude access to the public Certificate Transparency logs. Data comes from the Certificate Transparency logs run by Google, Sectigo and DigiCert. New certificates are ingested continuously as they appear, so recently issued ones typically show up shortly after issuance, and lookups reach back to 2018. Look up a hostname and get the certificates on record for it: the issuer, the certificate type, the validity window, and when each one was logged. Look up a domain to see the certificates logged across it, or start from a SHA-256 fingerprint to identify one certificate and the names it covers. Filter by issuer, by the date a certificate was logged, and by whether you want only currently valid certificates or expired ones as well. Two supporting tools report the state of the service: one gives the size of the index and when it was last updated, the other gives the allowance left on your account for the current hour. All three tools are read-only. Results come back as structured records, 25 rows by default and 100 at most, with a cursor for the next page. CTlogs reproduces publicly available Certificate Transparency log data without modification. Those entries are produced by certificate authorities and log operators. An account with an active plan is required. The free tier covers the website and the browser tools, but not the MCP connector.