YandexBot & robots
Official Yandex support articles for identifying the robot and robots.txt.
Yandex
Yandex documents Yandex robots and verification for YandexBot and related crawlers. Yandex does not ship a single downloadable CIDR JSON like major US search engines.
Autonomous systems
Network background
Yandex publishes reverse-DNS verification patterns (e.g. *.yandex.com, *.yandex.net) in webmaster help. Use those checks plus Yandex’s tools rather than static ASN guesses.
Published ranges
Official documentation and feeds for each product—open the links for current ranges and verification guidance.