Actors

Hyperactor programs are structured around actors: isolated state machines that process messages asynchronously.

Each actor runs in isolation, and maintains private internal state. Actors interact with the outside world through typed message ports and follow strict lifecycle semantics managed by the runtime.

This chapter introduces the actor system in hyperactor. We’ll cover:

• The Actor trait and its lifecycle hooks

• The Handler trait for defining message-handling behavior

• The RemoteSpawn trait for enabling remote spawning

• The remote actor registry for registering remotable-spawnable actors via remote! and spawning them by global type name

• The Checkpointable trait for supporting actor persistence and recovery

• The Referable marker trait for remotely referencable types

• The Binds trait for wiring exported ports to reference types

• The RemoteHandles trait for associating message types with a reference

• The ActorHandle type for referencing and communicating with running actors

• Actor Lifecycle, including Signal and ActorStatus

Actors are instantiated with parameters and bound to mailboxes, enabling reliable message-passing. The runtime builds upon this foundation to support supervision, checkpointing, and remote interaction via typed references.