Anthropic's official docs now make it crystal clear:
> OAuth authentication (used with Free, Pro, and Max plans) is intended exclusively for Claude Code and Claude.ai. Using OAuth tokens obtained through Claude Free, Pro, or Max accounts in any other product, tool, or service, including the Agent SDK, is not permitted and constitutes a violation of the Consumer Terms of Service. > Developers building products or services that interact with Claude's capabilities, including those using the Agent SDK, should use API key authentication through Claude Console or a supported cloud provider.
Anthropic also states they reserve the right to enforce this without prior notice.
If you're using OpenClaw or any similar third-party tool that routes through your Pro/Max credentials instead of proper API keys, be aware this violates the ToS and could result in enforcement action on your account.