Domain

Discover subdomains via Certificate Transparency logs

Queries crt.sh Certificate Transparency logs for every certificate issued for the domain and extracts unique subdomains from SAN entries. Passive/OSINT technique — no active scanning. Slower than other domain checks (crt.sh can be slow) and more tightly rate-limited: 5 requests/minute per IP.

post/api/v1/domain/subdomains

Request

  • Base URL: https://firstsales.io
  • URL: https://firstsales.io/api/v1/domain/subdomains
  • Auth: none required

Request body

domainstring required

Response

Discovered subdomains.

domainstring required
subdomainsstring[] required
countnumber required
source'Certificate Transparency (crt.sh)' required

Changes

No recorded changes to this operation across all 1 revision of this API.