It sounds like the keys just don't have any scoping. From the post:
> The Railway CLI token I created to add and remove custom domains had the same volumeDelete permission as a token created for any other purpose. Tokens are not scoped by operation, by environment, or by resource at the permission level. There is no role-based access control for the Railway API — every token is effectively root. The Railway community has been asking for scoped tokens for years. It hasn't shipped.
So every token that can be created has "root" permissions, and the author accidentally exposed this token to the agent. What was the author's planned purpose for the token doesn't matter if the token has no scope. "token I created to add and remove custom domains" - if that's just the author intent, but not any property of the token, then it's kinda irrelevant why the token was created, the author created a root token and that's it. Of course having no scope on tokens is bad on Railway's part, but it sounds more like "lack of a feature" than a bug. It wasn't "domain management token" that somehow allowed wrong operations, it was just a root token the author wanted to use for domain management. Unless Railway for some reason allows you to select an intent of the token, that does literally nothing (as "every token is effectively root").