Your server logs show a request from GPTBot. Should you trust it?
The honest answer is: not on the strength of that string alone. A user-agent header is a claim the client makes about itself, and any client can claim anything. curl -A "GPTBot" takes about four seconds to type. If your robots.txt policy, your analytics, or your paywall logic branches on the user-agent string, it branches on unverified input.
The good news is that most major AI crawlers publish a way to check. The less good news is that a meaningful minority publish nothing at all, and one whole category is unverifiable by design. This post covers how each verification method works, which crawlers support which, and where the honest answer is still "you cannot tell."
A user-agent string is a claim, not an identity
Three things are worth separating:
