Use the /user/idv/adhoc endpoint to run identity verification (IDV) ad hoc for an existing user, outside of user creation. You provide the userId, the Spidr idvTemplateId to run, and the productId the verification is intended for (the template must be enabled on that product).

The endpoint creates the IDV session and returns immediately. When the selected template uses Plaid's hosted flow, the response includes a shareableUrl the user visits to complete verification. The result arrives asynchronously: once the session completes and a decision is made, the passed session is recorded on the user and the user's CIP status is updated to pass or fail accordingly. A subsequent /account/create against the product can then reuse the passing session.