The biggest reason why this is confusing is the Claude Agent SDK[0] will use subscription/oauth credentials if present. The terms update implies that there's some use cases where that's ok and other use cases (commercial?) where using their SDK on a user's device violates terms.

[0] https://platform.claude.com/docs/en/agent-sdk/overview

Had the same question, comment below quotes their docs saying Agent SDK using oAuth token is also not allowed.

The SDK is Claude Code in a harnesss, so it works with your credentials the same way CC does.

But they're stating you can only use your subscription for your personal usage, not someone else's for their usage in your product.

I honestly think they're being short sighted not just giving a "3rd party quota" since they already show users like 4 quotas.

If the fear is 3rd party agents screwing up the math, just make it low enough for entry level usage. I suspect 3rd party token usage is bi-modal where some users just need enough to kick tires, but others are min-maxing for how mamy tokens they can burn as if that's its own reward