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