Find other domains DechoNet has seen with the same infrastructure value — a nameserver, IP address, MX host, certificate issuer or registrar — with first and last seen, to map related infrastructure (e.g. other phishing domains on the same rare nameserver). Use it after domain_history or dns_lookup gives you a distinctive value. Shared infrastructure (CDN edges, public CAs, large registrars and DNS hosts) returns a count only, since sharing it says nothing about ownership. Read-only; REQUIRES a free DechoNet API key (account page; remote: send Authorization: Bearer dn_…, npm: set DECHONET_API_KEY); 20 rows, 100 with MCP·API Pro; rate-limited. Coverage: only DechoNet's own observations.