Use the /sandbox/transactions/create endpoint to create new transactions for an existing Item. This endpoint can be used to add up to 10 transactions to any Item at a time.

This endpoint can be used with any Item created in the Sandbox environment. Added transactions persist across subsequent calls to /transactions/get and /transactions/sync.

Each transaction is added to the account named by its account_id. When account_id is omitted, the transaction is added to the Item's checking account, or, for a custom Sandbox user, to the first depository account listed in its override_accounts, or its first account if it has no depository account.