Reference

Tracked AI crawlers

The seven crawlers the checker tests robots.txt against, and why each matters.

The AI_CRAWLERS export (lib.js#L6-L14) is the exact list the crawler-access check tests against, and the list generate_ai_readiness_fixes welcomes in its robots.txt template:

User-agentFeeds
GPTBotChatGPT (OpenAI index and training)
OAI-SearchBotChatGPT Search
ClaudeBotClaude
PerplexityBotPerplexity
Google-ExtendedGoogle Gemini and AI Overviews
CCBotCommon Crawl (feeds many LLMs)
BingbotBing (powers ChatGPT Search results)

How blocking is evaluated

The robots.txt parser groups rules by User-agent and picks the most specific group for each crawler (exact name first, then *). A crawler counts as blocked only when its group carries Disallow: / or Disallow: /* without a root-level Allow (lib.js#L47-L64). Blocking some but not all tracked crawlers yields warn; blocking all seven yields fail.