Reactive Engine Core

@virtuoso.dev/reactive-engine-core is a framework-agnostic reactive state engine. State is modeled as a graph of typed nodes — stateful cells, stateless streams, and valueless triggers — connected through operators and combinators. An Engine instance activates the graph, propagates values, and manages subscriptions.

The package is part of the Reactive Engine family:

• @virtuoso.dev/reactive-engine-react - React bindings (provider and hooks)
• @virtuoso.dev/reactive-engine-query - data fetching with queries and mutations
• @virtuoso.dev/reactive-engine-router - routing with routes, layouts, and guards
• @virtuoso.dev/reactive-engine-storage - cell persistence in local/session storage or cookies

Installation

npm install @virtuoso.dev/reactive-engine-core

Quick Example

import { Cell, Engine } from '@virtuoso.dev/reactive-engine-core'

const count$ = Cell(0)
const engine = new Engine()

engine.sub(count$, (value) => {
  console.log('count is now', value)
})

engine.pub(count$, 1)
engine.getValue(count$) // 1

Concepts

• Cells are stateful nodes that always hold a current value.
• Streams are stateless nodes that emit values to their subscribers.
• Triggers are valueless streams used to signal events.
• Resources are cells with factory initialization and automatic disposal.
• Operators (map, filter, scan, debounceTime, throttleTime, withLatestFrom, and more) transform values as they flow between nodes.
• Combinators (link, pipe, combine, merge) wire nodes into a graph.
• Engine instances activate node definitions, propagate published values, and manage subscriptions.

License

MIT