Source CIDR

OpenAI

OpenAI publishes IP prefix lists for GPTBot, OAI-SearchBot, ChatGPT-User, and OAI-AdsBot at openai.com (gptbot.json, searchbot.json, chatgpt-user.json, adsbot.json). Those feeds are authoritative for allowlisting.

Autonomous systems

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.

Documentation

Anthropic Claude API IPs and crawler control notes. Perplexity Separate bot and user-request JSON feeds. GoogleBot Google crawler and user-triggered feed split. Common Crawl CCBot feed for broad web crawl traffic.