generated: '2026-08-05' method: probed source: https://developers.facebook.com/llms.txt description: Meta's llms.txt hierarchy. The root file is served as text/plain and links seven product sub-indexes, which together enumerate the .md documentation set. Every URL below was fetched on 2026-08-05. agent_policy: 'The root llms.txt carries a written agent conduct policy for the Marketing API and Ads MCP Server: agents must self-identify in the User-Agent as / () , append rather than replace, keep the name stable across requests, and not impersonate other agents.' content_negotiation: 'Same URL, two clients: a browser receives text/html with the markdown wrapped in

, while a self-identifying agent receives text/markdown or text/plain. Verified on
  the sub-indexes and on documentation pages; the payload difference is the HTML wrapper alone (for example
  ad-account.md: 62,679 bytes as a browser, 62,406 as an agent). A browser-shaped User-Agent WITHOUT Sec-Fetch-*
  headers is rejected with HTTP 400, while a plain client and an agent identifying itself per Meta''s
  own policy both receive 200.'
markdown_documents: 1607
documents_by_section:
  ads-commerce: 1063
  business-messaging: 368
  development: 70
  facebook-login: 52
  threads: 48
  development.md: 1
  mcp.md: 1
  ads-commerce.md: 1
  threads.md: 1
  facebook-login.md: 1
  mcp: 1
indexes:
- url: https://developers.facebook.com/documentation/ads-commerce/llms.txt
  bytes_as_browser: 110797
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/ads-commerce/marketing-api/reference/llms.txt
  bytes_as_browser: 61803
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/business-messaging/whatsapp/llms.txt
  bytes_as_browser: 47876
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/business-messaging/whatsapp/reference/llms.txt
  bytes_as_browser: 15998
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/development/llms.txt
  bytes_as_browser: 10729
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/facebook-login/llms.txt
  bytes_as_browser: 7693
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/mcp/llms.txt
  bytes_as_browser: 912
  content_type_as_browser: text/html
- url: https://developers.facebook.com/documentation/threads/llms.txt
  bytes_as_browser: 9046
  content_type_as_browser: text/html