Migrate
Move an existing Express, Koa, Fastify, or NestJS app to NextRush, retire deprecated imports, and plan version upgrades.
Each guide below maps concepts from one framework to their NextRush equivalent, using real before/after code. Pick the guide that matches where you're coming from — you don't need to read the others.
From Express
req/res/next → ctx, app.use() middleware, error handling.
From Koa
Closest existing mental model — ctx and the onion model, with real differences.
From Fastify
Schema-based validation, plugin encapsulation, and what NextRush does instead.
From NestJS
Decorators and DI — @Injectable/@Controller/@Module → @Service/@Controller/@Module.
Already on NextRush?
Breaking Changes
Retired shims, removed backward-compat aliases, and renamed internals — every real v4 API break.
v3 → v4 Docs Map
If you had a v3 documentation URL bookmarked, here is exactly where it moved.
Deprecations
@nextrush/decorators and @nextrush/controllers were removed — the canonical old-import → new-import map to nextrush/class.
Upgrade guide
What a version bump means today, and how to read a package's CHANGELOG before upgrading.
Every code sample here is verified against source
Every import shown in these guides is checked against the real package exports at the time of
writing (packages/*/src/index.ts) — not assumed from another framework's conventions or an
older NextRush release. If a page shows an import, that import exists.