`Meta-WebIndexer`

Meta says Meta-WebIndexer crawls to improve Meta AI search result quality, and that allowing the token helps Meta cite and link the site in Meta AI responses. The page says to block a crawler by adding a Disallow, and that a robots.txt change can take up to 24 hours. Meta-ExternalAgent is the training token on the same page. Meta-ExternalFetcher may bypass robots.txt and is not this card.

robots.txt token: Meta-WebIndexer
Operator: Meta
Kind: search
robots.txt: disallow_is_opt_out. The vendor says disallowing this token opts that use out.
HTTP user-agent: meta-webindexer/1.1 (+/documentation/sharing/webmasters/web-crawlers) Meta says the log string will be similar to this one or to meta-webindexer/1.1. On 2026-10-18 the page was text/markdown, and the parenthetical path has no host.
IP list: None on the cited page. This section does not publish an IP list.
Source: Meta Web Crawlers. Retrieved 2026-10-18.

JSON

curl -s https://whosthatbot.com/v1/crawlers/meta-webindexer

Check this token

tools/call with name check_robots is the same check at POST /mcp. The pasted file disallows Meta-WebIndexer on /docs and allows *. The call does not fetch a host.

curl -s https://whosthatbot.com/mcp -H 'content-type: application/json' -H 'accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"check_robots","arguments":{"robots_txt":"User-agent: Meta-WebIndexer\nDisallow: /\n\nUser-agent: *\nAllow: /\n","path":"/docs","ids":["meta-webindexer"]}}}'

That call returns fetched_target false. This row is disallow via group Meta-WebIndexer, rule Disallow: /.