nextjs-15-5-noteslisted

# Next.js 15.5 — current stable Current stable release of the 15.x line. **The 15.x line ends at v15.5.19** — 15.6 never shipped stable (canary-only) before the jump to 16.0, so there is **no `nextjs-15.6` module**. > React floor: 18/19 dual support. For React-language guidance (hooks, > concurrent features, migration), pair this cross-stack with the > `react-18` or `react-19` module. --- ## Signature features ### `next typegen` Introduced in 15.5.0. Generates TypeScript definitions for routes and route params, writing to `<distDir>/types`, without running a full `next build`: ```bash next typegen ``` ### Stable typed routes `typedRoutes` is promoted out of `experimental` — it is now a top-level `next.config` key (requires TypeScript in the project): ```js /** @type {import('next').NextConfig} */ const nextConfig = { typedRoutes: true } module.exports = nextConfig ``` ### Beta Turbopack production builds ```bash next build --turbopack ``` Turbopack production-build support was experimental in 15.3.0 and became **beta** in 15.5.0. Turbopack for `next dev` has been **stable since 15.0.0**. In 15.5, Turbopack is **not yet the default** for builds — you opt in with the flag; its absence still means webpack. ### AMP support deprecated AMP support is deprecated in the 15.x line. --- ## Migration traps ### `next lint` deprecated `next lint` is deprecated in 15.5 (scheduled for removal in 16 — cross-reference `nextjs-16-notes`). Migration path off it is the ESLint