# meta-externalfetcher

> Fetches a page when a Meta AI user asks about a specific link.

| field | value |
|---|---|
| operator | Meta |
| category | User-triggered fetchers |
| robots.txt token | `meta-externalfetcher` |
| user-agent contains | `meta-externalfetcher` |
| robots.txt | obeys robots.txt (documented) |
| verify by | no published verification method |
| published IP ranges | none published |
| prefixes mirrored | 0 IPv4 / 0 IPv6 |
| operator docs | https://developers.facebook.com/docs/sharing/webmasters/web-crawlers |
| last reviewed | 2026-09-01 |

## What blocking it costs you

Meta AI cannot read pages users hand it.

## Full user-agent string

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

## Block it

```
User-agent: meta-externalfetcher
Disallow: /
```

## Allow it

```
User-agent: meta-externalfetcher
Allow: /
```

JSON: https://www.pathwren.workers.dev/crawler/meta-externalfetcher.json · index: https://www.pathwren.workers.dev/llms.txt