YandexAdditionalBot
Yandex •
Web Crawler
What is YandexAdditionalBot?
Yandex lists YandexAdditionalBot among agents that help process robots.txt instructions intended to keep already indexed page content out of Search with Yandex AI responses. It does not make indexing requests. Yandex marks this agent as not taking the general robots.txt rules into account; site owners should follow Yandex's specific control guidance rather than treating it like the main YandexBot.
User Agent String
Mozilla/5.0 (compatible; YandexAdditionalBot/1.0; +http://yandex.com/bots)
How to Control YandexAdditionalBot
Block Completely
To prevent YandexAdditionalBot from accessing your entire website, add this to your robots.txt file:
# Block YandexAdditionalBot
User-agent: YandexAdditionalBot
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: YandexAdditionalBot
Disallow: /admin/
Disallow: /private/
Disallow: /wp-admin/
Allow: /public/
Set Crawl Delay
To slow down the crawl rate (note: not all bots respect this directive):
User-agent: YandexAdditionalBot
Crawl-delay: 10
How to Verify YandexAdditionalBot
Verification Method:
Use Yandex's forward-confirmed reverse-DNS check for source IPs; the user-agent string can be spoofed.
Use Yandex's forward-confirmed reverse-DNS check for source IPs; the user-agent string can be spoofed.
Learn more in the official documentation.
⚠️ AI Training Notice
This bot may collect and use your website content for AI model training. Consider whether you want your content used for this purpose before allowing access.
This bot may collect and use your website content for AI model training. Consider whether you want your content used for this purpose before allowing access.
Detection Patterns
Multiple ways to detect YandexAdditionalBot in your application:
Basic Pattern
/YandexAdditionalBot/i
Strict Pattern
/^Mozilla\/5\.0 \(compatible; YandexAdditionalBot\/1\.0; \+http\:\/\/yandex\.com\/bots\)$/
Flexible Pattern
/YandexAdditionalBot[\s\/]?[\d\.]*?/i
Vendor Match
/.*Yandex.*YandexAdditionalBot/i
Implementation Examples
// PHP Detection for YandexAdditionalBot
function detect_yandexadditionalbot() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/YandexAdditionalBot/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('YandexAdditionalBot detected from IP: ' . $_SERVER['REMOTE_ADDR']);
// Set cache headers
header('Cache-Control: public, max-age=3600');
header('X-Robots-Tag: noarchive');
// Optional: Serve cached version
if (file_exists('cache/' . md5($_SERVER['REQUEST_URI']) . '.html')) {
readfile('cache/' . md5($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for YandexAdditionalBot
import re
from flask import request, make_response
def detect_yandexadditionalbot():
user_agent = request.headers.get('User-Agent', '')
pattern = r'YandexAdditionalBot'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False
# Django Middleware
class yandexadditionalbotMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for YandexAdditionalBot
const express = require('express');
const app = express();
// Middleware to detect YandexAdditionalBot
function detect_yandexadditionalbot(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /YandexAdditionalBot/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('YandexAdditionalBot detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'YandexAdditionalBot';
}
next();
}
app.use(detect_yandexadditionalbot);
# Apache .htaccess rules for YandexAdditionalBot
# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} YandexAdditionalBot [NC]
RewriteRule .* - [F,L]
# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} YandexAdditionalBot [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]
# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "YandexAdditionalBot" is_bot=1
# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /YandexAdditionalBot/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for YandexAdditionalBot
# Map user agent to variable
map $http_user_agent $is_yandexadditionalbot {
default 0;
~*YandexAdditionalBot 1;
}
server {
# Block the bot completely
if ($is_yandexadditionalbot) {
return 403;
}
# Or serve cached content
location / {
if ($is_yandexadditionalbot) {
root /var/www/cached;
try_files $uri $uri.html $uri/index.html @backend;
}
try_files $uri @backend;
}
# Add headers for bot requests
location @backend {
if ($is_yandexadditionalbot) {
add_header Cache-Control "public, max-age=3600";
add_header X-Robots-Tag "noarchive";
}
proxy_pass http://backend;
}
}
Should You Block This Bot?
Recommendations based on your website type:
| Site Type | Recommendation | Reasoning |
|---|---|---|
| E-commerce | Limit Access | Protect pricing and inventory data from AI training |
| Blog/News | Consider Blocking | Your content may be used for AI training without compensation |
| SaaS Application | Block | No benefit for application interfaces; preserve resources |
| Documentation | Selective | Allow for public docs, block for internal docs |
| Corporate Site | Limit | Allow for public pages, block sensitive areas like intranets |
Advanced robots.txt Configurations
E-commerce Site Configuration
User-agent: YandexAdditionalBot
Crawl-delay: 5
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Disallow: /api/
Disallow: /*?sort=
Disallow: /*?filter=
Disallow: /*&page=
Allow: /products/
Allow: /categories/
Sitemap: https://example.com/sitemap.xml
Publishing/Blog Configuration
User-agent: YandexAdditionalBot
# Blocking AI training bot
Disallow: /
SaaS/Application Configuration
User-agent: YandexAdditionalBot
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
YandexAdditionalBot
Robots.txt Name
YandexAdditionalBot
Category
ai
Respects robots.txt
May not respect
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