ClaudeBot is Anthropic's web crawler used to collect training data for Claude AI models. Operating similarly to other AI training crawlers, ClaudeBot traverses the web to gather high-quality, publicly available content that helps improve Claude's understanding and capabilities. The bot adheres to ethical crawling standards, respecting robots.txt files and website owner preferences. Anthropic has designed ClaudeBot with their constitutional AI principles in mind, ensuring responsible data collection practices. Website owners can control ClaudeBot's access through standard robots.txt directives, effectively choosing whether their content contributes to Claude's training dataset.
User Agent String
ClaudeBot/1.0; +https://www.anthropic.com
How to Control ClaudeBot
Block Completely
To prevent ClaudeBot from accessing your entire website, add this to your robots.txt file:
⚠️ 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.
Detection Patterns
Multiple ways to detect ClaudeBot in your application:
// PHP Detection for ClaudeBot
function detect_claudebot() {
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$pattern = '/ClaudeBot/i';
if (preg_match($pattern, $user_agent)) {
// Log the detection
error_log('ClaudeBot 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($_SERVER['REQUEST_URI']) . '.html');
exit;
}
return true;
}
return false;
}
# Python/Flask Detection for ClaudeBot
import re
from flask import request, make_responsedef detect_claudebot():
user_agent = request.headers.get('User-Agent', '')
pattern = r'ClaudeBot'
if re.search(pattern, user_agent, re.IGNORECASE):
# Create response with caching
response = make_response()
response.headers['Cache-Control'] = 'public, max-age=3600'
response.headers['X-Robots-Tag'] = 'noarchive'
return True
return False# Django Middleware
class ClaudeBotMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
if self.detect_bot(request):
# Handle bot traffic
pass
return self.get_response(request)
// JavaScript/Node.js Detection for ClaudeBot
const express = require('express');
const app = express();// Middleware to detect ClaudeBot
function detectClaudeBot(req, res, next) {
const userAgent = req.headers['user-agent'] || '';
const pattern = /ClaudeBot/i;
if (pattern.test(userAgent)) {
// Log bot detection
console.log('ClaudeBot detected from IP:', req.ip);
// Set cache headers
res.set({
'Cache-Control': 'public, max-age=3600',
'X-Robots-Tag': 'noarchive'
});
// Mark request as bot
req.isBot = true;
req.botName = 'ClaudeBot';
}
next();
}app.use(detectClaudeBot);
# Apache .htaccess rules for ClaudeBot# Block completely
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} ClaudeBot [NC]
RewriteRule .* - [F,L]# Or redirect to a static version
RewriteCond %{HTTP_USER_AGENT} ClaudeBot [NC]
RewriteCond %{REQUEST_URI} !^/static/
RewriteRule ^(.*)$ /static/$1 [L]# Or set environment variable for PHP
SetEnvIfNoCase User-Agent "ClaudeBot" is_bot=1# Add cache headers for this bot
<If "%{HTTP_USER_AGENT} =~ /ClaudeBot/i">
Header set Cache-Control "public, max-age=3600"
Header set X-Robots-Tag "noarchive"
</If>
# Nginx configuration for ClaudeBot# Map user agent to variable
map $http_user_agent $is_claudebot {
default 0;
~*ClaudeBot 1;
}server {
# Block the bot completely
if ($is_claudebot) {
return 403;
}
# Or serve cached content
location / {
if ($is_claudebot) {
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_claudebot) {
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