Guides

@neutro/view (nv) is a fine-grained reactive view engine for the web. At v0.1.0 it is tagged, compilable, and benchmarked against comparable frameworks.

The design model

Components in nv run exactly once. During that single execution, signals record which DOM nodes read which values. When a signal changes, nv updates only those exact nodes — there is no virtual DOM, no re-render pass, and no diffing. For lists, a keyed reconciler moves real DOM nodes directly to handle reorders.

This makes the update path proportional to what changed, not to the size of the component tree.

See the Decision Log for the rationale behind these choices.

The four primitives

Primitive	Purpose
signal	A readable/writable reactive value
derived	A computed value that updates when its dependencies change
effect	A side-effectful computation that re-runs when its dependencies change
sync	A synchronous effect variant for write-time side effects

Also exported from core: pubsub, errorBoundary, batch, untrack, createRoot, onCleanup, flushSync.

Authoring model

Components are written in .nv files — a template format compiled by the esbuild plugin nvPlugin. The plugin emits IR-based code consumed by the renderer at runtime.

See Getting Started for install and plugin setup.

Package exports

@neutro/view/core

The reactive runtime. Has zero DOM dependency and can run in any JavaScript environment. Contains the four primitives and all scheduling utilities.

@neutro/view/compiler

Template IR types, sync-target classification, write-graph cycle checker, and §10 specialization hooks. Used by build tooling, not at runtime in the browser.

@neutro/view/renderer

Consumes the reactive core and renders Template IR to live DOM. Exports mount, html-tag helpers, and the IR types needed by component authors.

@neutro/view/renderer/runtime

A slim entry point for emitted bundles. Exports only mount — no parser, no TypeScript compiler. This is what the esbuild plugin links against in production builds.

What is not in v0.1.0

Async primitives, a store, context, and SSR are planned for v0.5.0 and are not available in this release.

In this section

• Authoring .nv — file format, erasure rules, template syntax, limitations
• Reactivity — signal, derived, effect, and all scheduling primitives
• Rendering — lists, conditionals, events, class bindings, scoped styles
• Architecture — the three-layer package structure and build pipeline