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What is Claude-User?

Claude-User is the agent Anthropic uses when a Claude user asks a question that needs a page read.

User-triggered fetchFollows robots.txtIP list
Operator
Anthropic
Purpose
User-triggered fetch. Fetches a page when a person asks an assistant about it.
robots.txt token
Claude-User
Sample user agent
Anthropic does not publish its user agent strings. Match on the token, not a full string.User agents change with versions. Match on the token, not the full string.
Follows robots.txt
Yes, according to Anthropic.
How to verify
Check the IP against Anthropic's published list.Anthropic publishes one list shared by all its bots.
Sources
Anthropic documentationAnthropic IP list
Last reviewed

Allow or block Claude-User

Block Claude-User
User-agent: Claude-User
Disallow: /

Asks Claude-User not to crawl any page. Well-behaved crawlers stop; it does not stop anyone who ignores robots.txt.

Allow Claude-User
User-agent: Claude-User
Allow: /

Lets Claude-User crawl everything. You only need this if a broader rule would otherwise block it.

Should you block it?

Claude-User only visits when a person asks Anthropic's assistant about your page. Blocking it means the assistant can't read the page that person asked about.

Write a full policy with the AI Crawler Policy Generator

How to verify a Claude-User request

  1. Find the IP address of the request in your server or CDN logs.
  2. Get Anthropic's published list (Anthropic IP list).
  3. Check whether the IP falls inside one of the ranges. If it doesn't, the request is not from Claude-User, whatever its user agent says.

Anthropic publishes one list shared by all its bots.

Test Claude-User requests

Questions about Claude-User

Is Claude-User safe to allow?

Claude-User reads public pages; it does not log in or submit forms. Whether to allow it depends on whether you want Anthropic's product to use your pages.

How do I know a request is really Claude-User?

Check the request against what Anthropic publishes: Check the IP against Anthropic's published list. The user agent alone proves nothing.

How often does Claude-User visit?

It depends on your site; Anthropic doesn't publish a schedule. Referscope shows the real visits.

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