{"uid":"cap_g_4HjDsB1SD-w1ZYYtOcy","slug":"sitecheck-ssl-certificate-transparency-lookup-567d58d3","name":"SiteCheck SSL Certificate Transparency Lookup","description":"Current TLS certificates for a domain from Certificate Transparency logs (via CertSpotter): issuer, validity dates and days left, DNS names (up to 100 per certificate), and the distinct subdomains seen. Keyless tier: one request per call; answers are cached an hour.","url":"https://api.sitecheck-api.workers.dev/api/certs?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["domain"],"properties":{"domain":{"type":"string","description":"Domain name, e.g. example.com"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"domain":"cloudflare.com","source":"https://api.certspotter.com/v1/issuances (Certificate Transparency logs)","current":[{"issuer":"SSL.com","daysLeft":136,"dnsNames":["staging.cp12.cloudflare.com"],"notAfter":"2027-02-27T18:53:54Z","notBefore":"2026-02-27T18:53:54Z"},{"issuer":"SSL.com","daysLeft":136,"dnsNames":["cp12.cloudflare.com"],"notAfter":"2027-02-27T18:53:58Z","notBefore":"2026-02-27T18:53:58Z"},{"issuer":"SSL.com","daysLeft":126,"dnsNames":["time.cloudflare.com","www.time.cloudflare.com"],"notAfter":"2027-02-17T21:30:57Z","notBefore":"2026-02-17T21:30:57Z"}],"checkedAt":"2026-10-14T07:00:57.376Z","issuances":100,"subdomains":["accounts-test.staging.realtime.cloudflare.com","accounts.staging.realtime.cloudflare.com","ai.cloudflare.com"],"attribution":"Certificate Transparency logs via CertSpotter"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_uJb9iOq5IzfcAuQxNAXG9","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Retrieves SSL/TLS certificate issuances for a domain from Certificate Transparency logs, including current certificates, subdomains, and expiry info","exampleAgentPrompt":"Pull up all the SSL certificates issued for stripe.com from certificate transparency logs — I want to see who issued them, which subdomains are covered, and how many days are left before they expire.","exampleUseCases":[{"title":"Subdomain discovery via cert logs","prompt":"Use certificate transparency logs to find all subdomains that have ever had a TLS cert issued for acmecorp.com — I want a full list of what's out there."},{"title":"Certificate expiry monitoring","prompt":"Check the SSL certificates for mycompany.com and tell me if any are expiring in the next 30 days so I can renew them before they lapse."},{"title":"Rogue certificate detection","prompt":"Look up all SSL certificates issued for ourbrand.com in the certificate transparency logs — I want to know if any were issued by a certificate authority we don't normally use, which could indicate a security issue."}],"resultDescription":"Returns a JSON object containing the domain queried, a list of current active certificates (each with issuer, DNS names covered, notBefore, notAfter, and daysLeft), a full list of discovered subdomains, total issuance count, the data source attribution (CertSpotter), and a checkedAt timestamp.","failureModes":["Invalid or non-existent domain returns an error or empty result","Domain with no certificate transparency entries returns empty issuances array","CertSpotter API upstream unavailability may cause timeout or error","Rate limiting on upstream CT log provider may delay response","Truncated subdomain list if domain has very large number of issuances"],"whenToPreferThis":"Use this endpoint when you need to audit SSL/TLS certificate history and coverage for a domain, discover subdomains via CT logs (a passive recon technique), check certificate expiry dates, or detect unexpected/rogue certificates issued by unauthorized CAs. Prefer this over DNS enumeration tools when you want certificate-sourced subdomain discovery without active scanning.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-28T06:39:09.046Z","isFirstParty":false,"canonicalSlug":"sitecheck-ssl-certificate-transparency-lookup-567d58d3"}