Create or locate a transaction banking account and attach a validated deposit product in a single request. On success, the endpoint generates a Deposit account opened event.

This endpoint supports two scenarios:

• Existing account: Provide both account.account_id and account.external_account_id. The Pismo platform locates the account via the transaction banking API and validates the IDs. If there is a mismatch, the request fails with a 400 error.

• New account: Provide account.external_account_id and the account_creation object. The Pismo platform creates a new transaction banking account and attaches the deposit product. If the transaction banking API returns 409 because the account already exists, the Pismo platform locates the existing account and proceeds with product attachment.

Note: The deposit product must exist, be of type deposit, and have an ACTIVE status.