A flow processor performs a specific business process based on a defined flow of states. A flow processor contains an initial state, one or more final states and any number of other states through which it might go. The toolkit definition file may contain flow processor definitions or, for self-defined processors, there are separate XML files. Each flow processor definition includes XML representations of all the parts and features that would be included in the statechart diagram of the flow.

A flow processor realizes the Automaton by implementing the Processor interface. The toolkit provides the DSEProcessor for Java clients and as a parent class for other flow processor classes. The DSEHtmlProcessor is an example of a flow processor implementation for HTML clients and is a subclass of DSEProcessor.

A processor contains an instance of a context for data and services management. All actions that the processor executes during its lifetime can access the processor context or use their own context. If the action does not have a defined context, the action uses the processor context. If the action does have a defined context, the toolkit chains the action context to the processor context. A processor can also have associated formats.