ChatGPT Agent (OpenAI)

ChatGPT's agent mode driving a real browser: it navigates and interacts with sites to finish a multi-step task a user gave it. OpenAI governs it with the ChatGPT-User token and the ChatGPT-User prefix list rather than a token of its own, so the robots rule and the address check are the same ones. Blocking it costs you: Agentic tasks a user asked for — booking, comparing, filling a form on your site — fail. This is the fetch that ends in a transaction, so it is the most expensive user-triggered block on this list. robots.txt token: ChatGPT-User.