Vite Patterns

Quick Guide: Vite serves unbundled ES modules in development and bundles for production, so most configuration decisions apply to only one of those halves. The version decides the API: Vite 8 bundles with Rolldown (build.rolldownOptions, codeSplitting.groups, resolve.tsconfigPaths), Vite 7 with Rollup (build.rollupOptions, manualChunks, aliases mirrored into tsconfig.json by hand). Sass runs on the modern API from Vite 6 onwards, and the legacy API is gone from Vite 7.

Detailed Resources:

• examples/core.md — full configs for aliases, chunk splitting, environment-specific builds, module preload, Sass, the Environment API and the dev proxy
• reference.md — dev/production settings, build-target table, per-version notes and the Vite 8 migration checklist

Which path applies

Read the vite version in package.json before writing config; the two branches share names and not behaviour.

• Vite 8 (Rolldown) — build.rolldownOptions, codeSplitting.groups for chunking, resolve.tsconfigPaths instead of hand-mirrored aliases. build.rollupOptions still resolves as a deprecated alias, which is why a wrong-version config looks like it works.
• Vite 7 (Rollup) — build.rollupOptions with manualChunks, and aliases declared in both vite.config.ts and tsconfig.json.