AFAIK, every tool out there that lets you do oauth with your Claude Max plan is doing so with the same copy-pasted client id/secret that are extracted from Claude Code. It's not clear at all that this is above board, and when I asked our Anthropic rep, they encouraged us not to do this.

If there's an official way for 3rd party devs to piggyback on Anthropic plans, someone please tell me how!