customerId | string | Yes | The customer to subscribe. |
priceId | string | Yes | The Stripe Price to subscribe them to. |
userId | string|number | No | Your own internal user ID, stamped on the returned record. |
quantity | number | No, defaults to 1 | Number of units of the price. |
trialPeriodDays | number | No | Length of a free trial before the first charge. |
collectionMethod | 'charge_automatically'|'send_invoice' | No, defaults to 'charge_automatically' | Whether Stripe charges the default payment method automatically, or emails an invoice for manual payment. |
daysUntilDue | number | Only with send_invoice | Defaults to 7. |
defaultPaymentMethodId | string | No | Payment method used for this subscription's charges. |
promotionCode | string | No | A Stripe promotion code ID (not a plain code string) applied at creation. |
metadata | Record<string,string> | No | Merged with source: "stripekit". |
fieldValues | Record<string,string> | No | Written into metadata as field_<key> and surfaced back as fieldValues on every subsequent read. |