@neutro/form

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@neutro/form

Zero-dependency reactive form engine for every framework.

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Framework Agnostic

First-class adapters for React, Svelte 5, Vue 3, SolidJS, and Angular. The core engine has zero runtime dependencies and works in any environment.

Pre-computed Dependency Graph

Cross-field validation dependencies are resolved into a transitive closure at init time. Runtime lookup is O(1) — no graph traversal on every keystroke.

Automatic GC

A lazy MutationObserver on document.body prunes disconnected DOM elements from the registry automatically. WeakRef ensures elements can be garbage-collected without leaking form state.

AbortController Async Validation

Every async validation invocation gets its own AbortController. Stale in-flight requests are cancelled immediately when the field changes, and epoch tracking prevents stale results from landing.

Array Operations

Built-in arrayAppend, arrayInsert, arrayRemove, arrayMove, and arraySwap keep errors, touched, and dirty maps in sync with the array's new indices automatically.

DOM Bridge

connect() links any HTMLElement to a form field path. getPayload() returns only values for currently-connected or persisted paths — perfect for multi-step wizards that unmount fields.

Why @neutro/form? ​

Most form libraries are coupled to a single framework or require a large runtime. @neutro/form ships a single closure factory — createForm<T> — that manages all form state internally. Framework adapters are thin reactive wrappers around the same engine, so you get identical validation behaviour, array operations, and DOM bridge semantics regardless of which UI framework you use.

ts
import { createForm } from '@neutro/form/core'

const form = createForm({
  initialValues: { email: '', password: '' },
  validator: (values) => {
    const errors: Record<string, string> = {}
    if (!values.email) errors.email = 'Required'
    if (values.password.length < 8) errors.password = 'Min 8 characters'
    return errors
  },
})

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Neutro Ecosystem ​

@neutro/form is part of the Neutro collection — focused, zero-dependency primitives for the web.

  • @neutro/form — the library you're reading about now
  • @neutro/fluid (coming soon) — a physics-grounded glass material system for the web

Support the Project ​

If this library saves you time, consider buying me a coffee. It keeps the packages maintained and the documentation up to date.

Found a bug or have a feature request? Open an issue on GitHub — see the Community page for guidelines.