> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/cloudflare/vinext/llms.txt
> Use this file to discover all available pages before exploring further.

# API Coverage

> Complete Next.js 16 API compatibility matrix for vinext

## Overview

vinext implements approximately **94% of the Next.js 16 API surface** with full or partial support. The remaining gaps are intentional stubs for deprecated features and edge cases.

<Note>
  **Legend:**

  * ✅ = Full implementation
  * 🟡 = Partial (runtime behavior correct, some build-time optimizations missing)
  * ⬜ = Intentional stub/no-op
</Note>

## Module Shims

Every `next/*` import is shimmed to a Vite-compatible implementation.

### Core Modules

| Module            | Status | Notes                                                                                                                                  |
| ----------------- | ------ | -------------------------------------------------------------------------------------------------------------------------------------- |
| `next/link`       | ✅      | All props including `prefetch` (IntersectionObserver), `onNavigate`, scroll restoration, `basePath`, `locale`                          |
| `next/image`      | 🟡     | Remote images via [@unpic/react](https://unpic.pics) (28 CDNs). Local images via `<img>` + srcSet. No build-time optimization/resizing |
| `next/head`       | ✅      | SSR collection + client-side DOM manipulation                                                                                          |
| `next/router`     | ✅      | `useRouter`, `Router` singleton, events, client-side navigation, SSR context, i18n                                                     |
| `next/navigation` | ✅      | `usePathname`, `useSearchParams`, `useParams`, `useRouter`, `redirect`, `notFound`, `forbidden`, `unauthorized`                        |
| `next/server`     | ✅      | `NextRequest`, `NextResponse`, `NextURL`, cookies, `userAgent`, `after`, `connection`, `URLPattern`                                    |
| `next/headers`    | ✅      | Async `headers()`, `cookies()`, `draftMode()`                                                                                          |
| `next/dynamic`    | ✅      | `ssr: true`, `ssr: false`, `loading` component                                                                                         |
| `next/script`     | ✅      | All 4 strategies (`beforeInteractive`, `afterInteractive`, `lazyOnload`, `worker`)                                                     |

### Fonts and Assets

| Module             | Status | Notes                                                                      |
| ------------------ | ------ | -------------------------------------------------------------------------- |
| `next/font/google` | 🟡     | Runtime CDN loading. No self-hosting, font subsetting, or fallback metrics |
| `next/font/local`  | 🟡     | Runtime `@font-face` injection. Not extracted at build time                |
| `next/og`          | ✅      | OG image generation via `@vercel/og` (Satori + resvg)                      |

### Cache and State

| Module       | Status | Notes                                                                                                                            |
| ------------ | ------ | -------------------------------------------------------------------------------------------------------------------------------- |
| `next/cache` | ✅      | `revalidateTag`, `revalidatePath`, `unstable_cache`, pluggable `CacheHandler`, `"use cache"` with `cacheLife()` and `cacheTag()` |
| `next/form`  | ✅      | GET form interception + POST server action delegation                                                                            |

### Legacy and Utility

| Module              | Status | Notes                                         |
| ------------------- | ------ | --------------------------------------------- |
| `next/legacy/image` | ✅      | Translates legacy props to modern Image       |
| `next/error`        | ✅      | Default error page component                  |
| `next/config`       | ✅      | `getConfig` / `setConfig`                     |
| `next/document`     | ✅      | `Html`, `Head`, `Main`, `NextScript`          |
| `next/constants`    | ✅      | All phase constants                           |
| `next/amp`          | ⬜      | No-op (AMP is deprecated)                     |
| `next/web-vitals`   | ⬜      | No-op (use the `web-vitals` library directly) |

## Routing Features

| Feature                          | Status | Notes                                                                                                              |
| -------------------------------- | ------ | ------------------------------------------------------------------------------------------------------------------ |
| File-system routing (`pages/`)   | ✅      | Automatic scanning with hot-reload on file changes                                                                 |
| File-system routing (`app/`)     | ✅      | Pages, routes, layouts, templates, loading, error, not-found, forbidden, unauthorized                              |
| Dynamic routes `[param]`         | ✅      | Both routers                                                                                                       |
| Catch-all `[...slug]`            | ✅      | Both routers                                                                                                       |
| Optional catch-all `[[...slug]]` | ✅      | Both routers                                                                                                       |
| Route groups `(group)`           | ✅      | URL-transparent, layouts still apply                                                                               |
| Parallel routes `@slot`          | ✅      | Discovery, layout props, `default.tsx`, inherited slots                                                            |
| Intercepting routes              | ✅      | `(.)`, `(..)`, `(..)(..)`, `(...)` conventions                                                                     |
| Route handlers (`route.ts`)      | ✅      | Named HTTP methods, auto OPTIONS/HEAD, cookie attachment                                                           |
| Middleware                       | ✅      | `middleware.ts` and `proxy.ts` (Next.js 16). Matcher patterns (string, array, regex, `:param`, `:path*`, `:path+`) |
| i18n routing                     | 🟡     | Pages Router locale prefix, Accept-Language detection, NEXT\_LOCALE cookie. No domain-based routing                |
| `basePath`                       | ✅      | Applied everywhere — URLs, Link, Router, navigation hooks                                                          |
| `trailingSlash`                  | ✅      | 308 redirects to canonical form                                                                                    |

## Server Features

### Rendering

| Feature                            | Status | Notes                                                                      |
| ---------------------------------- | ------ | -------------------------------------------------------------------------- |
| SSR (Pages Router)                 | ✅      | Streaming, `_app`/`_document`, `__NEXT_DATA__`, hydration                  |
| SSR (App Router)                   | ✅      | RSC pipeline, nested layouts, streaming, nav context for client components |
| React Server Components            | ✅      | Via `@vitejs/plugin-rsc`. `"use client"` boundaries work correctly         |
| Streaming SSR                      | ✅      | Both routers                                                               |
| Static export (`output: 'export'`) | ✅      | Generates static HTML/JSON for all routes                                  |

### Data Fetching

| Feature                         | Status | Notes                                                                                       |
| ------------------------------- | ------ | ------------------------------------------------------------------------------------------- |
| `getStaticProps`                | ✅      | Props, redirect, notFound, revalidate                                                       |
| `getStaticPaths`                | ✅      | `fallback: false`, `true`, `"blocking"`                                                     |
| `getServerSideProps`            | ✅      | Full context including locale                                                               |
| ISR                             | ✅      | Stale-while-revalidate, pluggable `CacheHandler`, background regeneration                   |
| Server Actions (`"use server"`) | ✅      | Action execution, FormData, re-render after mutation, `redirect()` in actions               |
| `"use cache"` directive         | ✅      | File-level and function-level. `cacheLife()` profiles, `cacheTag()`, stale-while-revalidate |

### Metadata

| Feature                | Status | Notes                                                                           |
| ---------------------- | ------ | ------------------------------------------------------------------------------- |
| Metadata API           | ✅      | `metadata`, `generateMetadata`, `viewport`, `generateViewport`, title templates |
| Metadata file routes   | ✅      | sitemap.xml, robots.txt, manifest, favicon, OG images (static + dynamic)        |
| `generateStaticParams` | ✅      | With `dynamicParams` enforcement                                                |

### Other Server Features

| Feature              | Status | Notes                                                                                 |
| -------------------- | ------ | ------------------------------------------------------------------------------------- |
| `connection()`       | ✅      | Forces dynamic rendering                                                              |
| `instrumentation.ts` | ✅      | `register()` and `onRequestError()` callbacks                                         |
| Route segment config | 🟡     | `revalidate`, `dynamic`, `dynamicParams`. `runtime` and `preferredRegion` are ignored |

## Configuration

| Feature                                 | Status | Notes                                |
| --------------------------------------- | ------ | ------------------------------------ |
| `next.config.js` / `.ts` / `.mjs`       | ✅      | Function configs, phase argument     |
| `rewrites` / `redirects` / `headers`    | ✅      | All phases, param interpolation      |
| Environment variables (`NEXT_PUBLIC_*`) | ✅      | Inlined at build time via Vite       |
| `images` config                         | 🟡     | Parsed but not used for optimization |

## Caching

The cache is pluggable. The default `MemoryCacheHandler` works out of the box. For production, use a custom backend:

```ts theme={null}
import { setCacheHandler } from "next/cache";
import { KVCacheHandler } from "vinext/cloudflare";

setCacheHandler(new KVCacheHandler(env.MY_KV_NAMESPACE));
```

The `CacheHandler` interface matches Next.js 16's shape, so community adapters should be compatible.

## Test Coverage

vinext's API compatibility is verified by:

* **1,700+ Vitest tests** — Unit and integration tests
* **380+ Playwright E2E tests** — Browser-based testing
* **Tests ported from Next.js** — Direct compatibility verification
* **OpenNext conformance suite** — Cloudflare deployment behavior

See the [test tracking document](https://github.com/cloudflare/vinext/blob/main/tests/nextjs-compat/TRACKING.md) for detailed results.

<Info>
  For features not supported, see the [Known Limitations](/advanced/known-limitations) page.
</Info>