Billing APIManage plans, track usage, view invoices, and handle payments.GET/api/v1/billing/planGet current subscription plan details.GET/api/v1/billing/usageGet current period usage metrics.GET/api/v1/billing/invoicesList billing invoices.POST/api/v1/billing/upgradeUpgrade or change subscription plan.GET/api/v1/billing/payment-methodsList saved payment methods.POST/api/v1/billing/credits/topupAdd credits to your account.PreviousPrompts APINextAuth API