Safe Official docs Search Engines

Yandex Object Answer API

Operated by Yandex

Quick Facts

User-Agent:
YandexOntoDBAPI
Category:
Search Engines
Operator:
Yandex
Safety:
Safe
Blocking Impact:
Low - No SEO ranking impact
SEO Impact Score:
2/10
Official docs:
yandex.com

Confirmed by the operator

Yandex names YandexOntoDBAPI on its own documentation page, linked above. The token, purpose and robots.txt behaviour on this profile come from that page, re-checked on September 22, 2026.

What is Yandex Object Answer API?

Yandex Object Answer API is an on-demand AI fetcher operated by Yandex. It retrieves a page only when a user explicitly asks an AI assistant or agent to read, summarize, or act on a specific URL. Because it is triggered by real user intent rather than bulk crawling, blocking it mainly prevents users from pulling your content into Yandex's assistant.

Yandex Object Answer API is an on-demand AI fetcher operated by Yandex. It retrieves a page only when a user explicitly asks an AI assistant or agent to read, summarize, or act on a specific URL. Because it is triggered by real user intent rather than bulk crawling, blocking it mainly prevents users from pulling your content into Yandex's assistant.
Yandex Object Answer API uses the user-agent token YandexOntoDBAPI. You can control it via robots.txt, meta tags (noai), or the emerging llms.txt standard. Robots.txt is voluntary; for hard enforcement, combine it with server-level IP blocking.

What happens if you block Yandex Object Answer API?

🔶 AI Visibility Trade-off - Blocking Yandex Object Answer API will not hurt Google or Bing rankings, but it can remove your content from AI search answers and assistant citations powered by this crawler. Block only if you have a deliberate reason.
Generally safe to allow; provides legitimate crawling value.

How to block Yandex Object Answer API with robots.txt

<code>User-agent: YandexOntoDBAPI</code> - Matching is case-insensitive. Robots.txt is fetched from the root of each subdomain separately.

Block completely (robots.txt)
User-agent: YandexOntoDBAPI Disallow: /
Allow all (robots.txt)
User-agent: YandexOntoDBAPI Allow: /
Block private only (robots.txt)
User-agent: YandexOntoDBAPI Disallow: /private/ Disallow: /api/ Disallow: /admin/ Allow: /
Nginx server block
# Nginx: Hard-block Yandex Object Answer API if ($http_user_agent ~* "YandexOntoDBAPI") { return 403 "Bot blocked"; }
Apache .htaccess
# Apache: Hard-block Yandex Object Answer API SetEnvIfNoCase User-Agent "YandexOntoDBAPI" bad_bot Order Allow,Deny Allow from all Deny from env=bad_bot
Meta robots tag
<meta name="robots" content="noindex, nofollow">
X-Robots-Tag header
X-Robots-Tag: noindex, nofollow

Is Yandex Object Answer API safe to allow?

Yes, Yandex Object Answer API is a safe and legitimate crawler operated by Yandex. It follows the Robots Exclusion Protocol (RFC 9309) and can be controlled with standard robots.txt rules.
Verify by reverse-DNS lookup: legitimate Yandex Object Answer API requests resolve to Yandex's domain.

What does Yandex Object Answer API do?

Understanding Yandex Object Answer API's purpose helps you decide whether to allow or block it.

  • Fetches a page only when a user asks an AI assistant to read it
  • Summarizes or extracts the URL the user provided
  • Triggered by real user intent, not bulk crawling
  • Low traffic volume compared with training crawlers
  • Blocking it prevents users from pulling your content into the assistant

Frequently Asked Questions

What is the official user-agent string for Yandex Object Answer API?
The official user-agent string for Yandex Object Answer API is: YandexOntoDBAPI. Use this exact string in robots.txt, Nginx, Apache, or Cloudflare firewall rules to target this bot. Matching in robots.txt is case-insensitive. Verify a request genuinely comes from Yandex Object Answer API by performing a reverse-DNS lookup on the source IP.
Is Yandex Object Answer API safe?
Yes, Yandex Object Answer API is a safe and legitimate crawler operated by Yandex. It follows the Robots Exclusion Protocol (RFC 9309) and can be controlled with standard robots.txt rules.
Will blocking Yandex Object Answer API hurt my SEO?
🔶 AI Visibility Trade-off - Blocking Yandex Object Answer API will not hurt Google or Bing rankings, but it can remove your content from AI search answers and assistant citations powered by this crawler. Block only if you have a deliberate reason.
How do I block Yandex Object Answer API in robots.txt?
Add the following lines to your /robots.txt file:
User-agent: YandexOntoDBAPI
Disallow: /

This instructs Yandex Object Answer API not to crawl any path on your site. To block only specific sections, replace / with the path (e.g., Disallow: /blog/).
Does Yandex Object Answer API respect robots.txt?
Yandex Object Answer API is operated by Yandex and is expected to fetch and parse /robots.txt before crawling, following RFC 9309. For hard enforcement, combine robots.txt with server-level IP or user-agent blocking.
How do I verify if Yandex Object Answer API is crawling my site?
Search your web server access logs for the string YandexOntoDBAPI (case-insensitive: grep -i "YandexOntoDBAPI" /var/log/nginx/access.log). Filter by user-agent in your log analytics tool (GoAccess, AWStats, etc.).

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