Valtio

Valtio — proxy-based state management for React, Vite-compatible.

App UtilsSimple

Stack Components

LibraryValtio 1.x

Why

Mutable API with proxy, no re-render boilerplate, snapshot for immutability. Utility libraries (lodash, date-fns, zod) save 100s of hours of boilerplate.

Zod reached 5M weekly npm downloads in 2024 as runtime validation became essential with TypeScript-first APIs.

When

Use for React state with mutable DX. Avoid for strict immutability needs.

How

1. npm install valtio 2. Create proxy state 3. useSnapshot for reads 4. Mutate directly 5. Add environment configuration — cp .env.example .env && edit values 6. Run tests — npm test or pnpm test to verify setup 7. Deploy — git push to trigger CI/CD or manual deploy

Example

import { proxy, useSnapshot } from 'valtio'; const state = proxy({ count: 0 }); function Counter() { const snap = useSnapshot(state); return <button onClick={() => state.count++}>{snap.count}</button>; }

Common Problems

⚠Mutating in render — always use useSnapshot
⚠Memory leaks — unsubscribe with proxySubscribe
⚠Configuration drift between environments — use infrastructure-as-code (Terraform/Pulumi) to keep dev/staging/prod identical

Best Practices

✓Use derive for computed state
✓Keep proxy state flat for simplicity
✓Set up health checks and graceful shutdown — handle SIGTERM to drain in-flight requests before exit

FAQ

What is Valtio and what projects is it for?

Valtio — proxy-based state management for React, Vite-compatible. It pairs layered technologies for end-to-end type safety and out-of-the-box deploys, fitting everything from MVPs to production SaaS.

How do I spin up a working demo with Valtio in 10 minutes?

Two steps: (1) npm install valtio; (2) Create proxy state. Get the local dev server running, then wire one real data source to verify the end-to-end loop.

What is the most common pitfall with Valtio and how do I avoid it?

The most common pitfall is: Mutating in render — always use useSnapshot. Avoid it by adding the matching checklist to your PR template and running type-check + lint + unit tests in CI — three gates before merge.

What are the best practices for Valtio?

Best practices for Valtio include: Use derive for computed state; Keep proxy state flat for simplicity; Set up health checks and graceful shutdown — handle SIGTERM to drain in-flight requests before exit. The first one — "Use derive for computed state" — should be set up at project init to avoid costly rework later.

When should I NOT choose Valtio?

Pick something else in three cases: (1) the team has zero experience with the core framework and the deadline is tight (learning-curve risk); (2) it's a pure content/marketing site (Astro is lighter); (3) you need very high throughput (>10k RPS) or strict-consistency microservices (Go/Rust). Valtio shines for mid-to-high complexity full-stack and API work — don't over-engineer simple static pages with it.