yacybot
YaCy •
Since 2006
Quick Actions
Official Docs
What is yacybot?
yacybot is the web crawler for YaCy, a free, decentralized, peer-to-peer search engine. Unlike traditional search engines, YaCy operates on a distributed network of nodes that collaboratively crawl and index the web without central control. Each YaCy node contributes to the shared search index. The bot respects robots.txt directives and is operated by individual users running YaCy nodes on their own hardware.
User Agent String
yacybot (/global; amd64 Linux 5.4.0; java 11.0.11; Etc/en) http://yacy.net/bot.html
How to Control yacybot
Block Completely
To prevent yacybot from accessing your entire website, add this to your robots.txt file:
# Block yacybot
User-agent: yacybot
Disallow: /
Block Specific Directories
To restrict access to certain parts of your site while allowing others:
User-agent: yacybot
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: yacybot
Crawl-delay: 10
How to Verify yacybot
Verification Method:
Check user agent string for yacybot identifier
Check user agent string for yacybot identifier
Learn more in the official documentation.
Detection Patterns
Multiple ways to detect yacybot in your application:
Basic Pattern
/yacybot/iStrict Pattern
/^yacybot \(/global; amd64 Linux 5\.4\.0; java 11\.0\.11; Etc/en\) http\://yacy\.net/bot\.html$/Flexible Pattern
/yacybot[\s\/]?[\d\.]*?/iVendor Match
/.*YaCy.*yacybot/iImplementation Examples
// PHP Detection for yacybot
function detect_yacybot() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/yacybot/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('yacybot 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for yacybot
import re
from flask import request, make_responsedef detect_yacybot():
user_agent = request.headers.get('User-Agent', '')
pattern = r'yacybot'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False# Django Middleware
class yacybotMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for yacybot
const express = require('express');
const app = express();// Middleware to detect yacybot
function detectyacybot(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /yacybot/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('yacybot detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'yacybot';
}
next();
}app.use(detectyacybot);
# Apache .htaccess rules for yacybot# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} yacybot [NC]
RewriteRule .* - [F,L]# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} yacybot [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "yacybot" is_bot=1# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /yacybot/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for yacybot# Map user agent to variable
map $http_user_agent $is_yacybot {
default 0;
~*yacybot 1;
}server {
# Block the bot completely
if ($is_yacybot) {
return 403;
}
# Or serve cached content
location / {
if ($is_yacybot) {
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_yacybot) {
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 | Allow | Essential for product visibility in search results |
| Blog/News | Allow | Increases content reach and discoverability |
| SaaS Application | Block | No benefit for application interfaces; preserve resources |
| Documentation | Allow | Improves documentation discoverability for developers |
| Corporate Site | Allow | Allow for public pages, block sensitive areas like intranets |
Advanced robots.txt Configurations
E-commerce Site Configuration
User-agent: yacybot
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: yacybot
Crawl-delay: 10
Disallow: /wp-admin/
Disallow: /drafts/
Disallow: /preview/
Disallow: /*?replytocom=
Allow: /
SaaS/Application Configuration
User-agent: yacybot
Disallow: /app/
Disallow: /api/
Disallow: /dashboard/
Disallow: /settings/
Allow: /
Allow: /pricing/
Allow: /features/
Allow: /docs/
Quick Reference
User Agent Match
yacybotRobots.txt Name
yacybotCategory
searchRespects robots.txt
Yes
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