Meta-ExternalFetcher
Fetches links on demand for Meta AI to summarise.
| Operator | Meta |
| Role | AI search crawlerRetrieves and verifies pages so an AI model can cite them as sources. |
| User agent token | Meta-ExternalFetcher |
| robots.txt | The operator documents honouring robots.txt. |
| Operator docs | developers.facebook.com |
Allow or block Meta-ExternalFetcher in robots.txt
Add either rule to the robots.txt at your site root. robots.txt is a request, not a lock: this operator documents honouring it, so the rule is normally enough.
Allow
User-agent: Meta-ExternalFetcher Allow: /
Block
User-agent: Meta-ExternalFetcher Disallow: /
Worth knowing before you block: this is a retrieval crawler. Blocking it removes your pages from what the AI models can read and cite live, which usually costs visibility rather than protecting anything.
Other Meta crawlers
- Meta-ExternalAgentTraining crawler
Is Meta-ExternalFetcher allowed on your site right now?
The free checker reads your robots.txt and probes your site as each AI crawler, so you see the policy and the reality in one pass.