ChildAt
Type, in @jr2/orchestrator/src/customize.ts. It is type plumbing: it computes a type from the types of a Machine or of its parts, and a workflow module does not write it. The signature of an export, or a type that it names, names this type, so its declaration is here. The Authoring surface page lists each export.
ts
type ChildAt<M extends AnyStateMachine, K extends string> = Extract<LogicAt<M, K>, AnyStateMachine>;