Meta-ExternalFetcher

Meta-ExternalFetcher fetches a page live when someone asks the AI platform about it. Most operators use a separate user agent for each job, so you can usually allow or block one without affecting the others.

Page fetches requested by AI platform users. A verified request establishes a page read, not a citation or a human visit.

This is a full user agent string Meta-ExternalFetcher sends. Version numbers change over time; match the Meta-ExternalFetcher token rather than the whole string.

To block Meta-ExternalFetcher, add this to the robots.txt at the root of your site:

Blocking it stops the assistant reading your page when a user asks for it, so the answer is built from other sources. Operators can treat user-requested fetches differently from automatic crawling; check the operator's documentation for how it applies robots.txt.

To allow it explicitly, for example after a broader rule blocks other crawlers:

Check what your robots.txt allows for Meta-ExternalFetcher and the other AI crawlers in this directory.

Meta does not publish a way to verify Meta-ExternalFetcher's requests, so any client can send this user agent. Treat traffic with this name as a claim, not proof.

SurfacedBy's AI traffic tracking recognizes Meta-ExternalFetcher in the user agent. Because SurfacedBy cannot confirm these requests come from Meta, they are shown separately as unverified and are not counted as crawls.

Details on this page come from Meta's own documentation: developers.facebook.com/documentation/sharing/webmasters/web-crawlers.

• Meta-ExternalAgentTraining
• meta-webindexerSearch indexing