AI bot reference

Claude-User: what this bot is and how to allow or block it

Claude-User is a bot from Anthropic that opens a page when a person asks: when someone using Claude asks it to read a link or the assistant looks up an answer right in the chat. It does not crawl the whole site — it reads one page at a time.

on request Claude · Anthropic

Claude-User User-Agent

This is how Claude-User identifies itself in requests to your site. In robots.txt you only write the token — Claude-User.

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Claude-User/1.0; [email protected])

Official bot documentation →

How to allow Claude-User

Add this group to robots.txt at the site root. Close service sections in the same group: a bot with its own group does not read the «User-agent: *» rules.

User-agent: Claude-User
Allow: /

robots.txt is not everything. If your site uses Cloudflare or other bot protection, it may serve Claude-User a 403 error or a challenge page even when robots.txt allows everything.

How to block Claude-User

To block the whole site, add the group below to robots.txt. The rule works for bots that respect robots.txt.

User-agent: Claude-User
Disallow: /

What happens if you block Claude-User

When someone using Claude asks it to open your page, the assistant will not be able to read it and will answer without your site.

How to check whether Claude-User visits your site

Search the web server logs for the token. The User-Agent string is easy to fake, so to be sure, check the IP address against the ranges if Anthropic publishes them.

grep "Claude-User" /var/log/nginx/access.log

Does your site let Claude-User in

Free 15-second check: we read your robots.txt and request your site as AI bots — you see which ones the server and bot protection let in and which they block.

Check a site

Questions and answers

Should I block Claude-User?

Usually not: Claude-User opens a page only when a person asks. Blocking it stops people using Claude from reading your site through it.

How do I know whether Claude-User visits my site?

Search the web server logs for the token. The User-Agent string is easy to fake, so to be sure, check the IP address against the ranges if Anthropic publishes them.

Is it enough to allow Claude-User in robots.txt?

robots.txt is not everything. If your site uses Cloudflare or other bot protection, it may serve Claude-User a 403 error or a challenge page even when robots.txt allows everything.