API ReferencePublic APICreate a subscription plan for a productCreate a subscription plan for a product POST /v1/products/:productId/plans Create a subscription plan for a product Request Responses201401403409422Plan createdAuthentication failedInsufficient permissionIdempotency or state conflictValidation errorDid this page unblock the next step?ResolvedNeeds improvementFeedback stays inside the docs flow and should never include customer or card data.