> I doubt there was much of a moat there anyway.

There is _a lot_ of moat. Claude subscriptions are limited to Claude Code. There are proxies to impersonate Claude Code specifically for this, but Anthropic has a number of fingerprinting measures both client and server side to flag and ban these.

With the release of this source code, Anthropic basically lost the lock-in game, any proxy can now perfectly mimic Claude Code.