ChatGPT-User is, alongside GPTBot (training) and OAI-SearchBot (ChatGPT Search), one of the three central OpenAI user agents. It activates when a user shares a specific URL in ChatGPT or makes a request that triggers a live fetch.
If you want users to be able to read and summarize a page directly in ChatGPT, allow the retrieval:
User-agent: ChatGPT-UserAllow: /
If is blocked, ChatGPT cannot read the page directly for a specific user request. Distinguishing the three OpenAI bots matters: blocking them all indiscriminately prevents not only training but also the search and retrieval functions relevant for .