Create an organization's savings account product. Savings account products accrue interest based on the balance at the time of the interest calculation.
This endpoint generates the Savings account product created event. For information about interest-bearing accounts, see Interest-bearing accounts. The interest plan is fetched once and used to resolve or validate accrual_model before any resource configuration. Missing, null, or empty values derive the model from the plan. An explicit mismatch returns HTTP 400 EIBACC0365. An unknown nonempty plan model or a missing plan object returns HTTP 500 EIBACC0007, and errors from the interest plan API are passed through. None of these failures configure resources, persist a product, or publish a creation event.