Next.js Engine (NE) is a schema-driven compiler and runtime for React 19 and Next.js 16. Typed page schemas become explicit execution plans, server-owned content remains server-first, and browser work is isolated into targeted interactive islands.
Generation 3 builds on foundations established by earlier Engine generations while defining its own compiler-first execution model, runtime boundaries, and API contract. This README documents Generation 3 only.
Warning
Generation 3 is alpha software. APIs, compiler behavior, and package snapshots may change. Pin the exact version or source commit and validate your application before production use.
Source version: 3.0.0-alpha.1 in main-3/package.json
Rolling Alpha: channel-alpha-latest — currently labelled 3.0.0-alpha.1.
Numbered archive: 3.0.0-alpha.2 package snapshot — includes the ne CLI executable.
Alpha.1 notes: Generation 3 alpha.1
The source manifest and rolling channel still identify alpha.1. The alpha.2 snapshot is a separate immutable package archive.
| System | Purpose |
|---|---|
| Schema compiler | Deterministic execution plans, feature manifest, fallbacks, assets, and diagnostics |
| Server-first renderer | Server-owned output and targeted client islands |
| Shared scheduler | Coordinates viewport, model, media, canvas, scroll, and deferred work |
| EngineTheme | Validated themes, variants, safe templates, Data-API, .etr artifacts, and font compilation |
| Custom components | Trusted local React components with declared props, slots, and theme references |
| EngineOverlay | Dialog, drawer, popover, focus, portals, stacking, and scroll lock |
| EngineCanvas / EngineSVG | Retained graphics, Canvas 2D, 3D, SVG, and shader rendering |
| EngineShader / EngineScroll | Compiled GPU effects, points, timelines, ranges, and tracking |
| EngineManim | Timeline-based 2D/3D animation |
| EngineImage / EngineVideo | Viewport-aware media |
| EngineBrowser | SSR-safe browser capability helpers |
| EngineSEO | Metadata, sitemap, robots, JSON-LD, and social previews |
| EngineAPIResolver / APIStatic | API orchestration and compiled browser endpoint programs |
| NENC / EngineCookies | Server-owned commands, device/session proof, and authorization |
| NE CLI | Build/check commands and release-channel tooling |
| EngineDebug / Error Book | Development inspection, global errors, and diagnostics |
Generation 3 compiles a typed page schema before rendering. The compiler prepares an execution plan that records server-owned output, targeted client islands, required features, compatible fallbacks, assets, and diagnostics. This gives the renderer a clear plan for what stays on the server and what needs browser interaction.
compilePage()creates the compiled plan, feature manifest, fallback plan, assets, and diagnostics.createPage()uses the Generation 3 compilation and server-rendering path.- Browser-only behavior is isolated into client islands.
- Compatibility planning considers the features a page actually uses.
Read the compiler deep dive.
EngineTheme provides validated theme definitions, qualified IDs, local/global/preloaded remote resolution, .etr artifacts, declarative templates, typed Data-API, highlighting, and font compilation.
Trusted custom React components declare props and slots, register under a stable schema-node ID, and can reference EngineTheme. Theme data controls appearance; trusted component code owns behavior.
import { createComponent, registerComponent } from "nextjs-engine";
const SiteLink = createComponent({
mode: "custom",
id: "site-link",
theme: "site.link",
component: SiteLinkImplementation,
props: { href: { type: "string", required: true, maxLength: 2048 } },
slots: ["children"],
strictProps: true,
});
registerComponent("site-link", SiteLink);Remote .etr files remain declarative data; they do not execute JavaScript, JSX, or arbitrary imports. Read EngineTheme.
- NENC connects named commands to server-owned handlers. Authentication, authorization, validation, replay policy, and secrets remain server responsibilities.
- EngineSEO generates metadata and crawler/social outputs from declared site and page data.
- EngineDebug provides development route, preview, runtime, scheduler, and device/viewport inspection.
- Global error handling supplies subsystem-coded diagnostics, terminal reporting, and an Error Code Book.
See the NENC security model, EngineSEO, and global error handling.
import { createPage, defineSchema, EngineCanvas, EngineScroll, EngineDialog,
EngineDrawer, EnginePopover, EngineBrowser, EngineSEO, APIStatic } from "@kastrick/nextjs-engine";import { getServerDevice } from "@kastrick/nextjs-engine/server";const withEngine = require("@kastrick/nextjs-engine/plugin");
module.exports = withEngine({});The archived alpha.2 package snapshot includes the CLI executable:
ne --version
ne
ne dev
ne build
ne start
ne check
ne clean
ne updater
ne update --channel alpha
ne rollback
ne helpThe rolling Alpha channel still points to alpha.1 release metadata. Verify the numbered snapshot and publication status before installing; the archive and moving channel are distinct.
npm install
npm run type-check
npm run dev
npm run build
npm run test:cli
npm run test:theme
npm run test:browserStart with the Generation 3 documentation index.
| Topic | Guide |
|---|---|
| Compiler and rendering | Compiler deep dive |
| Styling | Simple guide · Detailed guide |
| Theme system | EngineTheme |
| Overlays | EngineOverlay |
| Graphics | EngineCanvas |
| Scroll | EngineScroll |
| GPU effects | EngineShader |
| SEO | EngineSEO |
| Errors | Global error handling |
| Performance | Runtime performance |
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Warning
Disclaimer: Nextjs Engine is an independent open-source framework created by Kastrick and Developer Kate-alt-69. It is not affiliated with, endorsed by, or sponsored by Vercel Inc. or Meta Platforms, Inc.
Built by Kate-alt-69 for the Kastrick platform. See LICENSE.