domain-infra-history
Shodan
A search engine for internet-connected devices and services that also keeps historical service banners. You query it through its own web interface, which we link to; an official API exists but requires a key and is mostly paid. Researchers reach for it when tracing what services or software a host has exposed over time, as part of domain and infrastructure history work.
No programmatic check — opens the archive’s own search.
Why it’s useful & how it works
Niche/link-catalogue tier (see product-concept): surfaced as a described link to its search form. Probe verdict recorded for liveness.
API access
https://api.shodan.io/ (key; mostly paid)
An API key is required — usually free; see the endpoints above for where to get one.
Access
Freely reachable — no key, login, or captcha.