YandexAdditionalBot

Verifiable

Yandex's robot for processing robots.txt so that site owners can keep already indexed page content out of the AI responses shown in Yandex Search. Yandex's robot table states it applies to pages that have already been indexed by the primary crawler and that it makes no indexing requests of its own.

Operated by Yandex · Official documentation

User agents

Patterns this directory matches, with real observed strings.

regexYandexAdditionalBot/\d
regexYandexAdditional/\d
observedMozilla/5.0 (compatible; YandexAdditionalBot/1.0; +http://yandex.com/bots)
observedMozilla/5.0 (compatible; YandexAdditional/1.0; +http://yandex.com/bots)

How to verify

Reverse-DNS check a client IP

dig -x <client-ip> +short   # expect a hostname matching *.yandex.ru

Reverse-DNS suffixes: *.yandex.ru, *.yandex.net, *.yandex.com

Good Bot Practices scorecard

Identifies honestly
Stable UA token documented (2 patterns)
Verifiable
Verifiable
Respects robots.txt
Does not honor robots.txt
Behaves
Crawl-rate behavior is operator-declared; not machine-verifiable from this dataset
Reachable operator
Operator and documentation published

Measured against the Good Bot Practices.