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Claude-User user agent

Operated by Anthropic · Live answers · Answering you

robots.txt token
Claude-User

Claude-User identifies itself with the token Claude-User. That is the case-insensitive substring to grep for in access logs, and the exact name to put after User-agent: in robots.txt. It fetches a page live, at the moment a user asks something.

Allow or block Claude-User in robots.txt

Robots.txt applies the most specific matching group, so a group naming Claude-User overrides your User-agent: * rules for this bot alone.

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

What blocking costs you: Claude can't fetch your pages when someone asks it about them, so you drop out of its user-directed web answers.

To see which AI crawlers your robots.txt allows right now, run your domain through the AI crawler access checker. To check whether AI answers actually cite you, use the AI citation checker.

Anthropic's other crawlers

Blocking one Anthropic bot does not block the others — each token is a separate group.

Anthropic's own documentation: https://support.claude.com/en/articles/8896518

FAQ

What is the Claude-User user agent?
Claude-User announces itself with the User-Agent token "Claude-User". That token is the case-insensitive substring to match in server logs and the exact name to put after "User-agent:" in robots.txt. Anthropic does not publish one fixed full string, so match on the token rather than the whole line.
Who operates Claude-User and what does it collect?
Claude-User is run by Anthropic and fetches a page live, at the moment a user asks something. In the AI picture that puts it under "Answering you": A live user prompt made an AI fetch your page to answer.
How do I block Claude-User?
Add a robots.txt group naming the token exactly: User-agent: Claude-User followed by Disallow: /. Robots.txt matches the most specific group, so a Claude-User group overrides whatever your User-agent: * group says. Claude can't fetch your pages when someone asks it about them, so you drop out of its user-directed web answers.
Should I block Claude-User?
That depends on what you lose. Claude can't fetch your pages when someone asks it about them, so you drop out of its user-directed web answers. Sites chasing AI citations usually keep the live-answer and AI-search bots open and make a separate decision about the training crawlers. Run your domain through the AI crawler access checker to see which ones your robots.txt lets in today.
Can Claude-User be spoofed?
Yes. A User-Agent header is self-reported, so any scraper can claim to be Claude-User. The token is fine for reporting and for robots.txt, but if you are rate-limiting or firewalling on it, verify the request IP against Anthropic's published ranges before you trust the name.

Paste a full User-Agent line and identify any crawler with the AI bot user agent list and lookup, or see every token side by side.