Vite and framework support

Oganesson runs Vite's own configuration, environment, builder, and plugin code inside its build host. Bundling is performed by Rollup or by a Rolldown-compatible facade over Go esbuild, depending on the installed Vite major version.

Vite versions and build model

• Vite 5 through 7 use the WebAssembly build of Rollup and Oganesson's Go-backed replacement for the esbuild npm package.
• Vite 8 uses Oganesson's Rolldown API facade over Go esbuild.
• The build script's vite build invocations and CLI flags are honored.
• Client assets are served with Vite-preview-style fallback and base-path behavior.
• Server environments are rebundled for Sobek with Node built-ins and og:* modules available.
• CSS-only modules, emitted assets, dynamic-import preload lists, manifests, source maps, plugin hooks, aliases, import.meta.glob, and dynamic-import variables are supported.

The facade follows Rollup plugin order and contexts for resolution, loading, transformation, emitFile, resolveFileUrl, renderChunk, generateBundle, and writeBundle. Chunk membership still follows esbuild's splitter, so output graphs may differ from native Rolldown even when URLs and behavior match.

Set OG_VITE_TRACE=1 during a build to log plugin hook calls.

Validated SPA stacks

The following static/client application combinations have repository fixtures:

Stack	Covered behavior
React	JSX/TypeScript, assets, CSS, lazy chunks, base paths
Vue	Vue SFCs, <script setup lang="ts">, scoped styles
Svelte 5	runes, TypeScript, scoped styles, transform source maps
Preact	@preact/preset-vite and its Babel path
Solid	vite-plugin-solid
Tailwind CSS 4	@tailwindcss/vite and oxide WebAssembly
UnoCSS	generated utility CSS
TanStack Router	file-based SPA routing, loaders, navigation
vite-plugin-pwa	generateSW, service-worker output, manifest, precache

SSR server programs

If the project builds an SSR entry and its preview, start, or serve script runs node <file> or a dependency's server binary, Oganesson packages that program and its build outputs.

At runtime the program executes in each request's isolated VM. Its http.createServer(...).listen() call does not open another listening socket; Oganesson hands the current request to the registered listener and converts the Node response back to a Web Response. This model is validated with:

• Express;
• Fastify;
• Koa;
• Hono with @hono/node-server; and
• h3.

The server program can read its packaged build outputs through node:fs, use import.meta.url, perform dynamic imports of packaged modules, stream a response, and serve static assets. Startup logging is emitted once per process even though the program is initialized in request VMs.

Server programs cannot accept WebSocket upgrades or open their own inbound net.Server/tls.Server listeners.

TanStack Start

Validated TanStack Start behavior includes:

• SSR and browser hydration;
• route loaders;
• GET and POST server functions;
• request middleware and server routes;
• deferred data and streaming;
• prerendered routes;
• SPA mode while retaining the framework server's rendering semantics;
• redirects, not-found responses, headers, cookies, and errors; and
• the React Server Components variant with its provider environment.

One upstream Start limitation also occurs under real Vite: a server function reachable only through a client component nested in a server component may not be registered. Reference it from the route graph.

Meta-frameworks

The following production build and server shapes are validated:

Framework	Implemented shape
Astro	Static output and server output with @astrojs/node; Markdown and Shiki/Oniguruma WebAssembly paths
VitePress	Static documentation sites through VitePress's own build and page-rendering API; custom themes, local search, clean URLs, and public assets
React Router framework mode	SSR, loaders, actions, resource routes, prerendering, and react-router-serve
SvelteKit	SSR, server loads, form actions, endpoints, prerendering, CSS, error pages, and adapter-node
Nuxt	Nuxt build, Nitro server output and prerendering
SolidStart	Vite/Nitro build and server output
Qwik City	Qwik build scripts, optimizer WebAssembly, and the Node server adapter

Oganesson recognizes these frameworks' normal build and start scripts; no Oganesson-specific server entry is required.

VitePress currently needs build-host-safe options: disable lastUpdated (it spawns Git through child_process), Markdown-it's automatic linkify, and native CSS minification. Explicit Markdown links and unminified CSS work normally. This site's VitePress config is a complete working example.

Filesystem and deployment behavior

Static Vite apps package the client output. SSR server-program applications package the build outputs under the runtime virtual filesystem and use / as their working directory. The packaged layer is readable; writes go to a shared in-memory overlay for the lifetime of the process.

Use an external filesystem path, database, or service for persistent state. Writing a relative file inside the packaged filesystem does not modify the executable and does not survive a restart.

Vite-specific limits

• manualChunks, advanced chunk groups, and code-splitting groups influence names and warnings but do not move modules between esbuild's chunks.
• augmentChunkHash is not implemented; hashes are esbuild's pre-render values.
• this.parse/parseAst does not parse TypeScript syntax.
• Plugin preview-server middleware is not generally run. Supported frameworks' built servers are served directly instead.
• Vite development-only native-binding paths, the dev server, dependency optimizer, and HMR are outside the production build path and unsupported.
• Browser and server output can differ structurally from native Rollup/Rolldown output, including chunk grouping and renamed identifiers in stringified functions. Validated behavior, URLs, statuses, and data match.