APIAPIRetrieves a single subscription by id.
AuthorizationRequiredBearer <token>API key as Bearer token
In: header
idRequiredstringSubscription id, discoverable via list_subscriptions
fieldsstringComma-separated list of fields. Valid: id, hostId, contactId, customerEmail, priceId, quantity, items, status, currentPeriodStart, currentPeriodEnd, trialStart, trialEnd, billingCycleAnchor, cancelAt, cancelAtPeriodEnd, canceledAt, cancelReason, endedAt, startedAt, dunningEnabled, autoCharge, paymentDueDays, taxRate, notes, taxIds, firstFailureAt, nextRetryAt, retryCount, metadata, createdAt, updatedAt. Omit for all.
Create Subscription
Creates a new subscription against an active recurring Price. Starts in `trialing` if trialDays is set, else `incomplete` (awaiting first payment).
Update Subscription (mid-cycle change with proration)
Changes a subscription's priceId and/or quantity mid-cycle and issues a Stripe-style daily-prorated invoice for the rate difference. Allowed on active or trialing subs only (trialing skips proration entirely — the new price takes effect at trial end). The new price must be active, recurring, and the same currency as the current one. Downgrades that net <= 0 apply without generating a credit invoice (v1 has no credit balance — the customer simply pays less at next renewal).