Claude-User: purpose, robots.txt rules and access checks

Technical reference

Operator	Anthropic
Class	User-triggered browsing
HTTP User-Agent	Product token: Claude-User. The operator reference does not specify a fixed full header.
Citation impact	Blocking it can prevent Claude from retrieving the requested page through this agent.
IP verification	Official IP ranges or verification reference

Header versions can change. Use the product token for robots.txt matching and consult the Anthropic crawler documentation before changing enforcement. Reference checked on 18 October 2026.

How do I allow Claude-User?

Merge this group into the robots.txt served from the page's origin. Keep any path exclusions that still apply. A named group may stop inheriting the wildcard group's exclusions.

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User-agent: Claude-User
Allow: /

Allow retrieval and block training

This example separates the operator's documented identities where possible. It changes crawl or data-use preferences; it does not grant server access. User-triggered agents may follow a different robots.txt policy.

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User-agent: Claude-SearchBot
Allow: /

User-agent: Claude-User
Allow: /

User-agent: ClaudeBot
Disallow: /

Use the interactive robots.txt builder for a per-bot policy. Test the final file against the exact page path before deploying it.

What if the CDN returns HTTP 403?

A robots.txt allow rule cannot override an HTTP 403, a login gate or a JavaScript challenge. Compare the returned body with the public page and locate the request in CDN security events. Grant an exception only after verifying the sender, scoped to the affected public routes.

The scanner uses its own network. A successful header probe does not verify Anthropic access, and a refused probe does not establish a vendor-wide block. See the WAF troubleshooting guide.

Check your site's rules for Claude-User

Public page URL Check Claude-User access

Frequently asked questions

What does Claude-User do?

Anthropic operates Claude-User. Claude-User retrieves web pages in response to a user request.

Does blocking Claude-User affect citations?

Blocking it can prevent Claude from retrieving the requested page through this agent.

How do I verify a Claude-User request?

Use the operator's published verification reference linked on this page. Match the source IP, not just the User-Agent header. A scanner probe comes from its own network.