Valtio

Valtio is a proxy-based state management library and reactive state engine that provides a mutable state store. It allows application state to be updated through direct object mutations rather than immutable patterns, using JavaScript proxies to track changes and trigger updates. For React applications, it includes a synchronization hook that ensures components re-render only when the specific properties they access are modified.

The system supports reactive data derivation through computed properties that automatically update when their underlying dependencies change. It maintains reactivity across deep data structures via nested proxy composition and extends this tracking to native Map and Set collections.

Additional capabilities include state composition for nesting or splitting state objects and the ability to subscribe to changes across the entire state tree. The library provides mechanisms for transient state updates to read values without triggering re-renders and supports the storage of untracked objects to reduce memory overhead.

Features

Application State Management - Provides a proxy-based system for managing shared application state that triggers targeted React component re-renders.

Observable State Tracking - Uses JavaScript proxies to detect data access and modifications, enabling state updates through direct object mutations.

Mutable Stores - Implements a store that enables state updates through direct mutations instead of immutable patterns.

Mutable State Tracking - Allows complex JavaScript objects to be updated via direct mutations while automatically notifying listeners.

Mutable State Transitions - Updates application state through standalone functions, grouped objects, or class methods that modify proxy objects.

Reactive Component Models - Ensures UI components re-render only when the specific state properties they access are modified.

Recursive Proxy Wrapping - Recursively wraps nested objects and collections in proxies to maintain reactivity across deep structures.

Reactive State Systems - Provides a reactive engine for defining computed properties and subscriptions based on shared state.

Computed Properties - Implements derived state using JavaScript getters that automatically update based on dependencies.

Derived State - Computes derived state values that automatically update when source state properties change.

Dependency Tracking - Tracks specific state properties accessed during render to minimize component re-renders.

React State Bindings - Ships a synchronization hook that connects proxy state to React components for optimized rendering.

State Management Libraries - Utilizes JavaScript proxies to track state mutations and trigger reactive updates.

Hierarchical State Composition - Combines independent state objects into nested structures or splits large states into smaller reactive pieces.

State Change Subscriptions - Enables listeners to respond to updates occurring within the entire state object or specific nested sections.

Event Subscribers - Maintains a list of subscribers notified whenever a mutation occurs within the proxy state tree.

Rendering Optimizations - Optimizes frontend rendering by tracking specific property access to prevent unnecessary updates.

Snapshot State Semantics - Creates immutable state snapshots to ensure data consistency during a render cycle.

Scoped State Containers - Isolates state within specific component subtrees using refs and context to prevent global persistence.

Mutation Batching Controls - Allows disabling mutation batching to trigger immediate re-renders for debugging and synchronous feedback.

Reactive Collection Wrappers - Provides reactive proxy wrappers for native JavaScript Map and Set collections to maintain synchronization.

Transient State Reads - Provides the ability to read state values without triggering a re-render to maintain high performance.

Frontend Development - A proxy-based state management library for React.

State Management - Proxy-based state management for simple reactivity.

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Features

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