{"uid":"cap_x5y4LRv52Lgb_RDmI7zBO","slug":"dns-subdomain-discovery-api-313fd4fb","name":"DNS Subdomain Discovery API","description":"DNS records, WHOIS, SSL certificate, subdomain discovery, and reverse-IP lookup with x402 payments.","url":"https://dns.payapi.market/dns/subdomains?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"limit":{"type":"integer","maximum":1000,"minimum":1,"description":"Maximum number of subdomains to return. Defaults to 200."},"domain":{"type":"string","description":"Apex domain to enumerate subdomains for via Certificate Transparency logs, e.g. 'example.com'."}}},"responseSchema":{"type":"json","example":{"count":3,"domain":"example.com","source":"crt.sh (Certificate Transparency logs)","subdomains":["api.example.com","mail.example.com","www.example.com"],"total_unique":3}},"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_9vzi9mdkVxGLXfJVvZzHT","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":"Enumerates subdomains for a given apex domain using Certificate Transparency logs (crt.sh)","exampleAgentPrompt":"Can you find all the subdomains of stripe.com using Certificate Transparency logs — return up to 500 results?","exampleUseCases":[{"title":"Attack surface mapping for security audit","prompt":"I'm doing a security assessment on acme-corp.com — can you pull up to 1000 subdomains from Certificate Transparency logs so I can map out their attack surface?"},{"title":"Competitor infrastructure reconnaissance","prompt":"What subdomains does shopify.com have? Give me up to 300 results so I can understand how they've structured their infrastructure."},{"title":"Pre-acquisition domain due diligence","prompt":"We're considering acquiring example.io — can you enumerate their subdomains from CT logs, up to 200, so we can assess how complex their web presence is?"}],"resultDescription":"Returns a JSON object containing the queried apex domain, the data source (crt.sh Certificate Transparency logs), a list of discovered subdomains, the count of returned subdomains, and the total unique subdomain count.","failureModes":["Invalid or non-existent domain returns empty subdomain list","Domain with no CT log entries returns zero results","Limit parameter out of range (below 1 or above 1000) causes validation error","Network timeout if crt.sh is slow or unavailable","Payment failure via x402 if insufficient USDC balance"],"whenToPreferThis":"Choose this endpoint when you need passive subdomain discovery sourced from Certificate Transparency logs without active scanning — ideal for security research, asset inventory, and reconnaissance where stealth matters. Prefer it over active DNS brute-force tools when you want a quick, non-intrusive snapshot of a domain's known subdomains.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-17T12:30:12.893Z","isFirstParty":false,"canonicalSlug":"dns-subdomain-discovery-api-313fd4fb"}