What is YandexAdditionalBot?
A robots.txt token Yandex uses to let sites keep page content out of Search with Yandex AI answers. Yandex says it applies to pages already indexed by its main crawler and does not make indexing requests.
Indexes pages so an AI search product can cite and link them in answers. Blocking it usually means you stop showing up as a source there.
Rules under User-agent: * do not apply to it, so name it directly. Yandex says changes take effect when its robots recrawl the page, typically in 2 to 14 days.
YandexAdditionalBot user agent
Yandex documents these user agents for YandexAdditionalBot. Version numbers in it change over time, so match on the name, not the whole string.
Mozilla/5.0 (compatible; YandexAdditionalBot/1.0; +http://yandex.com/bots)
Mozilla/5.0 (compatible; YandexAdditional/1.0; +http://yandex.com/bots)Should you block YandexAdditionalBot?
Usually allow it. It is how an AI search product finds pages to cite and link, so blocking it trades away being a source in those answers.
How to block YandexAdditionalBot in robots.txt
Add a group for its tokens to robots.txt at the root of your site. Yandex says it follows robots.txt only in part, so this may not stop every fetch.
A bot follows only the group that names it, so it ignores your User-agent: * rules once it has a group of its own. Repeat any paths you also want kept from it there.
User-agent: YandexAdditional
User-agent: YandexAdditionalBot
Disallow: /How to verify a request is really YandexAdditionalBot
Anyone can send any user agent, so the string alone proves nothing.
Or check by reverse DNS: look up the hostname of the request’s IP, confirm it ends in yandex.ru or yandex.net or yandex.com, then look that hostname up again and confirm it points back to the same IP.
See when YandexAdditionalBot reads your site
Bots don’t run JavaScript analytics, so a script tag never sees them. invisit records crawler reads on the server instead, through its server SDK or a Cloudflare Worker, and shows which bots read which pages, next to your visitors.
Checked against Yandex’s own documentation on . Something changed? Write to help@invisit.dev.