Meta-ExternalAgent

Operator

Meta

Type

AI Assistant

Official page

developers.facebook.com

robots.txt token

meta-externalagent

Follows robots.txt

Yes, according to Meta.

In Vireo

Excluded, reported under AI crawlers

What it does

Crawls the web for uses such as training foundation AI models or improving products by indexing content directly.

The Meta-ExternalAgent crawler crawls the web for use cases such as training foundation AI models or improving products by indexing content directly.

Meta

User agent

Requests from Meta-ExternalAgent carry user agents like these:

meta-externalagent/1.1

meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler)

Device Detector identifies it with this pattern (a case-insensitive regular expression):

meta-externalagent

Anyone can put any name in a user agent. Where the operator publishes IP ranges, checking the request's address against them is the way to confirm a visit is genuine.

How to block or allow Meta-ExternalAgent

Add a group for its token to the robots.txt file at the root of your site. To keep it out of the whole site:

User-agent: meta-externalagent
Disallow: /

To let it crawl everything, use an empty Disallow: or Allow: / instead. WordPress serves a virtual robots.txt that many SEO plugins let you edit. A real robots.txt file uploaded to the site root takes its place.

User-agent: meta-externalagent

Meta

In order to block these crawlers, add a disallow for the relevant crawler to robots.txt.

Meta

robots.txt is a request, so it only works on crawlers that honour it. A bot that ignores it has to be blocked at the server or firewall, by user agent or IP address.

Worth knowing

robots.txt changes can take up to 24 hours because Meta caches the file.

Please allow up to 24 hours for changes to robots.txt to take effect because crawlers may cache the contents of robots.txt for up to 24 hours.

Meta

How Vireo counts Meta-ExternalAgent

Vireo keeps requests from Meta-ExternalAgent out of your pageviews and visitors and counts them on its bot report under AI crawlers, so you can see how much it left out rather than wonder why your server logs show more traffic.

Because it's an AI crawler, its requests also count toward the pages AI crawlers took, which Vireo shows next to the readers AI assistants sent back. See how the AI assistants card works.

Checked by running Vireo Analytics' own bot filter over Meta-ExternalAgent's user agents.

Sources

• Meta: crawler documentation (checked October 2026)
• Meta-ExternalAgent information page (developers.facebook.com)
• Matomo Device Detector, bots.yml (LGPL-3.0)
• ai.robots.txt (MIT)