Claude-User

Operated by Anthropic · Fetches when a user asks

If you block it

Claude stops fetching your page on a user’s behalf — and unlike the equivalent at OpenAI and Perplexity, Anthropic says this one honors the rule.

When individuals ask questions of Claude, it may access websites using a Claude-User agent.

robots.txt: Says it respects robots.txt“Covered by the same statement: Anthropic honors robots.txt directives across its bots.”
User agent: Not published as a full string. Anthropic publishes only the token.Match on the prefix Claude-User rather than the whole string: operators version these, and an exact match stops working on the next release.
Verification: Published address list: https://claude.com/crawling/bots.json