1. Overview

Stateflows overview

Stateflows is a .NET framework for implementing addressable, event-driven Behaviors. A behavior instance processes incoming events according to its definition and retains state between interactions.

The framework provides four core behavior types:

Behavior	Model	Typical use
Action	A discrete operation	Work that does not need a structured lifecycle or graph
State Machine	UML state-machine concepts	Interactive processes and lifecycle-driven behavior
Activity	UML activity concepts	Token-processing and data-flow graphs
Entity	Persistent fields, mutations, and projections	Domain data with controlled updates and queryable views

State Machines and Activities use UML-based models; Actions and Entities provide complementary behavior models. All behavior types use the configured runtime for execution, addressing, event delivery, and scheduling; every host must configure a runtime. See Runtimes for the transitional Legacy runtime and the recommended Orleans runtime.

Start with Installation, then use Behaviors for identity, lifecycle, interaction, and model selection. Cross-cutting topics such as messaging, validation, scheduling, and observability are documented separately. Optional integrations are listed under Extensions; a runtime is mandatory and hosting is covered under Runtimes.