Last updated: 2016-03-10
Works with CiviCRM 4.6. It might not be supported anymore.
This extension adds a new API to CiviCRM: Entity is FinancialItem, action is Get. You can also use the derived actions getsingle, getvalue, getcount etc.
As there is only a retrieve function in the CiviCRM Core BAO CRM_Financial_BAO_FinancialItem which retrieves a single financial item there is also a class CRM_Financialitem_FinancialItem with a method getValues to get the Financial Items with a param list.
The extension has been developed for one project which uses CiviCRM 4.4, and I have also tested it locally against CiviCRM 4.6.