Your current plan, billing window and available changes (dashboard session required)

Reports the plan this account is on, the billing window it is in, any tier change already staged for the next invoice, and the full pricing ladder marked up so you can see which rungs are an upgrade and which a downgrade. planChangesGoThrough is the field to branch on: self_serve means POST /v1/subscription/plan can move you; provider_managed means Square’s own recurring subscription holds your price and neither this API nor a new checkout can move it — buying again would create a SECOND Square subscription and charge you twice; checkout appears only when you have no plan at all, where starting one is exactly right. All money is in integer minor units (cents). AUTHENTICATION IS YOUR DASHBOARD SESSION, NOT AN API KEY. Send the @sp/core session cookie this API sets when you sign in, from the same origin. An API key is refused here on purpose: it is a data-plane credential that lives in CI and in third-party integrations, and it must never be able to change what you are billed, cancel your account, or read your payment history. Errors: 401 unauthenticated when there is no valid session, 403 forbidden when the request is cross-origin or its x-csrf-token header is missing or wrong.