There are currently two APIs for accessing workflow objects: the classic Workflow API (or WfAPI for short) and the Unified API. While it is still supported for legacy stand-alone clients and server-side extensions, CoreMedia recommends that such code be ported to the Unified API.

The Unified API covers all workflow-related functionality required for developing client-side applications. In comparison to the WfAPI, it is integrated much better with the content repository, and provides a simpler model for accessing workflow variable values.

When migrating a WfAPI client to the Unified API, note that what is a process in the Unified API used to be called a "process instance" in the WfAPI, while a process definition in the Unified API used to be called a "process" in the WfAPI, and similarly for tasks.

The state hierarchy has been reshuffled slightly (compare the state charts in the Workflow Manual and in this manual). Note, that some events have been renamed, shown in Table 6.1, “WfAPI signal names and UAPI event classes”. There are no per-object listeners in the Unified API, only the WorkflowRepositoryListener. The WfAPI's directory service functionality is covered completely by the Unified API's user repository.