This appears to be a part of a crackdown on third-party clients using Claude Code's credentials/subscriptions but not through Claude Code.
Not surprising as this type of credential reuse is always a gray area, but weird Anthropic deployed it on a Thursday night without any warning as the inevitable shitstorm would be very predictable.
Not surprising as this type of credential reuse is always a gray area, but weird Anthropic deployed it on a Thursday night without any warning as the inevitable shitstorm would be very predictable.