Claude-User — Anthropic's user-triggered fetcher

Traffic is query-driven and page-specific rather than site-wide: single fetches at the moment of a user request, with volume tracking how often your pages come up in Claude conversations.

Like other server-side fetchers it never executes your analytics JavaScript, so this readership is invisible in GA4 and appears only in server or CDN logs.

Claude-User identifies itself with the following user-agent string:

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Claude-User/1.0; +https://www.anthropic.com)

Never trust the user-agent string alone. Scrapers routinely impersonate well-known crawlers to inherit their access. Documented by Anthropic alongside its other bots; verify unexpected volumes against DNS and Anthropic's published guidance.

Note that most AI crawlers and fetchers, Claude-User included, do not execute JavaScript — so this traffic is invisible to GA4 and every script-based analytics tool. Server logs, CDN analytics, or a dedicated bot-analytics layer are the only places you will see it. For the full picture of measuring AI-driven visits, see our guide on how to track AI traffic.

To refuse Claude-User access to your entire site, add this to your robots.txt:

User-agent: Claude-User
Disallow: /

To restrict it from specific sections only (for example, premium content) while leaving the rest open:

User-agent: Claude-User
Disallow: /premium/
Disallow: /members/

The case for blocking: Blocking prevents Claude from reading your pages even on explicit user request — the right call only for hard-paywalled content you don't want summarized on demand.

The case for allowing or monetizing: On-demand agent fetches for a human reader are the canonical monetizable agent visit: per-fetch licensing or sponsored context can price the consumption that used to be a pageview.