OpenAI

Official

OpenAI publishes IP prefix lists for GPTBot, OAI-SearchBot, ChatGPT-User, and OAI-AdsBot, plus ChatGPT connectors (plugins/Actions) and ChatGPT agents / Codex cloud egress feeds at openai.com. Those feeds are authoritative for allowlisting; prefer request auth (mTLS/OAuth) where OpenAI documents it.

Autonomous systems (ASNs)

Known ASNs used by OpenAI.

BGP & cloud context

Published prefix lists are authoritative for each bot product; WHOIS may still show Azure or other cloud ASNs. Combine published prefixes with rDNS and OpenAI’s docs.

Third-party hosting & clouds

Microsoft Azure

AS8075 AS12076

Common Azure ASNs; align enforcement with OpenAI’s published prefix list.