What is meta-externalagent?
meta-externalagent is Meta's web crawler for uses such as AI model training. Meta AI citations and link previews come from other Meta crawlers.
Also called Meta-ExternalAgent.
Full guide: What Is Meta-ExternalAgent? What Meta's Crawlers Do, and Which to Block
Meta's crawler documentation says Meta-ExternalAgent "crawls the web for use cases such as training foundation AI models or improving products by indexing content directly." It is one of five crawlers Meta lists. Meta-WebIndexer helps Meta AI "cite and link to your content," facebookexternalhit builds link previews, meta-externalfetcher fetches pages at a user's request, and meta-externalads serves advertising products.
A robots.txt group naming meta-externalagent with "Disallow: /" blocks it without touching the others, and Meta says its crawlers may cache robots.txt for up to 24 hours. Meta prefers robots.txt to "non-standard formats like NoAI tags." Its doc publishes no IP list for verifying visits.
Why does it matter to your business?
Blocking meta-externalagent is how a site declines Meta's AI training while staying citable in Meta AI and keeping link previews on Facebook and Instagram.
Sources, verified October 31, 2026
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