The Content API for Microsoft FAST Search Server 2010 for SharePoint enables your application to add and remove indexed content within FAST Search Server 2010 for SharePoint by using the Microsoft .NET Framework.
NO NEW VERSIONS, LIMITED SUPPORT: Note that this API is released as deprecated. The API is provided to enable users to integrate non-SharePoint content sources only with FAST Search Server 2010 for SharePoint. This API will not work with any future version of FAST Search Server for SharePoint. This API is provided "as is"; Microsoft may not provide support services for it.