anthropic-ai: robots token, verification and how to allow or disallow it
anthropic-ai is an AI crawler operated by Anthropic. Its robots.txt token is anthropic-ai, and the vendor documentation we fetched on 2026-09-06 is the source for every statement on this page.
| Robots token | anthropic-ai |
|---|---|
| Vendor | Anthropic |
| Purpose | undocumented |
| Documented verification | none published |
| Vendor documentation last verified | 2026-09-06 |
| Share of read domains disallowing it for / | 7.8% of 128 |
| Last verified |
Identity
| Robots token | anthropic-ai |
|---|---|
| Matched as | anthropic-ai |
| Vendor | Anthropic |
| Purpose | undocumented |
| Documentation | None |
| Documented verification | none published |
documentation_url is null on purpose: the vendor help article fetched on 2026-09-06 documents three robots (ClaudeBot, Claude-User, Claude-SearchBot) and contains zero occurrences of 'anthropic-ai'. The token is still widely present in site robots.txt files, so it stays in the registry as a legacy token whose current behaviour the vendor does not document.
Allow or disallow it
User-agent: anthropic-ai Allow: /
User-agent: anthropic-ai Disallow: /
A robots.txt rule is a request that a well behaved crawler honours. It is not an access control, and this page does not tell anyone what to choose.
Questions
How do I allow anthropic-ai in robots.txt?
Add this group to the robots.txt at the root of the host: User-agent: anthropic-ai Allow: /. The token is matched case insensitively as a substring of the user agent by RFC 9309, and the longest matching rule wins.
How do I disallow anthropic-ai in robots.txt?
Add this group to the robots.txt at the root of the host: User-agent: anthropic-ai Disallow: /. A robots.txt rule is a request that a well behaved crawler honours; it is not an access control.
How do I verify a request really came from anthropic-ai?
We have not found a documented verification method for anthropic-ai: the vendor publishes neither an IP range file nor a reverse DNS convention that we could fetch. Without one, a user agent string is not evidence of origin.
What we measure
Of the 128 seeded domains whose robots.txt we have read, 10 disallow anthropic-ai for / and 118 allow it, which is 7.8% disallowed, week 2026-W37. Counts only: no domain is named.
The weekly AI crawler access index
Sources
| Source | Type | HTTP | Verified | Note |
|---|---|---|---|---|
| https://darkvisitors.com/agents/anthropic-ai | aggregator | 200 | 2026-09-06 | only source found; third party, not the vendor; volatile source: identical byte count but a different content hash on every fetch (verified twice on 2026-09-06), so the refresher compares byte counts for it, not hashes |
| https://support.claude.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler | vendor | 200 | 2026-09-06 | negative evidence: 0 occurrences of anthropic-ai |
Free data
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AEO Watch is an independent, factual monitor. It is not affiliated with, endorsed by or speaking for any crawler vendor. Every statement is an observation with the date it was made and the raw evidence behind it: a robots.txt line, an HTTP status code, a header. There are no scores, no grades and no verdicts here, and nothing on this page is advice. A site opts out at any time and the opt out is honoured automatically and permanently.