vite-advanced

Advanced configuration for Vite 7+ including Environment API.

Vite 7 Environment API (Key 2026 Feature)

Multi-environment support is now first-class:

import { defineConfig } from 'vite'

export default defineConfig({
  environments: {
    // Browser client
    client: {
      build: {
        outDir: 'dist/client',
        manifest: true,
      },
    },
    // Node.js SSR
    ssr: {
      build: {
        outDir: 'dist/server',
        target: 'node20',
      },
    },
    // Edge runtime (Cloudflare, etc.)
    edge: {
      resolve: {
        noExternal: true,
        conditions: ['edge', 'worker'],
      },
      build: {
        outDir: 'dist/edge',
      },
    },
  },
})

Key Changes:

• Environments have their own module graph

• Plugins access this.environment in hooks

• createBuilder API for coordinated builds

• Node.js 20.19+ or 22.12+ required

Plugin Development

Basic plugin structure:

export function myPlugin(): Plugin {
  return {
    name: 'my-plugin',

    // Called once when config is resolved
    configResolved(config) {
      // Access resolved config
    },

    // Transform individual modules
    transform(code, id) {
      // this.environment available in Vite 7+
      if (id.endsWith('.special')) {
        return { code: transformCode(code) }
      }
    },

    // Virtual modules
    resolveId(id) {
      if (id === 'virtual:my-module') {
        return '\0virtual:my-module'
      }
    },
    load(id) {
      if (id === '\0virtual:my-module') {
        return 'export const value = "generated"'
      }
    },
  }
}

SSR Configuration

Development (middleware mode):

import { createServer } from 'vite'

const vite = await createServer({
  server: { middlewareMode: true },
  appType: 'custom',
})

app.use('*', async (req, res) => {
  const url = req.originalUrl
  let template = fs.readFileSync('index.html', 'utf-8')
  template = await vite.transformIndexHtml(url, template)

  const { render } = await vite.ssrLoadModule('/src/entry-server.tsx')
  const html = template.replace('<!--outlet-->', await render(url))

  res.send(html)
})

Production build scripts:

{
  "scripts": {
    "build:client": "vite build --outDir dist/client",
    "build:server": "vite build --outDir dist/server --ssr src/entry-server.tsx"
  }
}

Build Optimization

export default defineConfig({
  build: {
    target: 'baseline-widely-available', // Vite 7 default
    sourcemap: false,
    rollupOptions: {
      output: {
        manualChunks: {
          vendor: ['react', 'react-dom'],
          router: ['react-router-dom'],
        },
      },
    },
  },
})

Quick Reference

| Environment API | Stable

| ESM-only distribution | Default

| Node.js requirement | 20.19+ or 22.12+

| buildApp hook | New for plugins

| createBuilder | Multi-env builds

Key Decisions

| Multi-env builds | Use Vite 7 Environment API

| Plugin scope | Use this.environment for env-aware plugins

| SSR | Middleware mode for dev, separate builds for prod

| Chunks | Manual chunks for vendor/router separation

Related Skills

• biome-linting - Fast linting alongside Vite

• react-server-components-framework - SSR integration

• edge-computing-patterns - Edge environment builds

References

• Environment API - Multi-environment builds

• Plugin Development - Plugin hooks

• SSR Configuration - SSR setup

• Library Mode - Building packages

• Chunk Optimization - Build optimization