DNS Subdomain Discovery API

x402

DNS Subdomain Discovery API is a paid API for AI agents from dns.payapi.market, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-17).

Enumerates subdomains for a given apex domain using Certificate Transparency logs (crt.sh)

Price / call$0.002

Seller volume →—

Success—

StatusUnknown

How this service works

DNS records, WHOIS, SSL certificate, subdomain discovery, and reverse-IP lookup with x402 payments.

Output

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.

Example use cases

Attack surface mapping for security audit

“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?”

Competitor infrastructure reconnaissance

“What subdomains does shopify.com have? Give me up to 300 results so I can understand how they've structured their infrastructure.”

Pre-acquisition domain due diligence

“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?”

Technical details

Endpoint

POSThttps://dns.payapi.market/dns/subdomains?utm_source=zero.xyz

When to prefer

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.

Side effects

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

Input

Schema · Request body

Field	Type	Description
limit	integer	Maximum number of subdomains to return. Defaults to 200.
domain	string	Apex domain to enumerate subdomains for via Certificate Transparency logs, e.g. 'example.com'.

Output

Schema · Response

{
  "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
  }
}

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How this service works

DNS records, WHOIS, SSL certificate, subdomain discovery, and reverse-IP lookup with x402 payments.

Output

Example use cases

Attack surface mapping for security audit

“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?”

Competitor infrastructure reconnaissance

“What subdomains does shopify.com have? Give me up to 300 results so I can understand how they've structured their infrastructure.”

Pre-acquisition domain due diligence

“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?”

Technical details

Endpoint

POSThttps://dns.payapi.market/dns/subdomains?utm_source=zero.xyz

When to prefer

Side effects

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

Input

Schema · Request body

Field	Type	Description
limit	integer	Maximum number of subdomains to return. Defaults to 200.
domain	string	Apex domain to enumerate subdomains for via Certificate Transparency logs, e.g. 'example.com'.

Output

Schema · Response

{
  "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
  }
}