# General Translation React SDKs (gt-react, gt-next): App Router middleware
URL: https://generaltranslation.com/en-US/docs/react/nextjs/app-router-middleware.mdx
---

title: App Router middleware
description: How to configure General Translation locale routing for the Next.js App Router.
related:
  links:
    - /docs/react/nextjs-quickstart
    - /docs/react/nextjs/app-router-static-site-generation
    - /docs/react/nextjs/reference/functions/create-next-middleware

---

Configure middleware, a `[locale]` root segment, and a request locale function so App Router requests resolve to the correct localized route.

## Configure the middleware [#middleware]

Create `proxy.ts` in your project root (`middleware.ts` on Next.js 15 and earlier):

```ts title="proxy.ts"
import { createNextMiddleware } from 'gt-next/middleware';

export default createNextMiddleware();

export const config = {
  matcher: ['/((?!api|static|.*\\..*|_next).*)'],
};
```

The middleware detects the locale from the URL, cookie, browser headers, or default locale. It then redirects or rewrites the request to the matching localized route.

## Add the locale route [#locale-route]

Move your App Router pages under `app/[locale]`:

<Files>
  <Folder name="app">
    <Folder name="[locale]">
      <File name="layout.tsx" />
      <File name="page.tsx" />
    </Folder>
  </Folder>
  <File name="getLocale.ts" />
  <File name="proxy.ts" />
</Files>

The route segment receives the locale selected by the middleware. See [`createNextMiddleware`](/docs/react/nextjs/reference/functions/create-next-middleware) for routing options and localized path configuration.

## Read the root locale [#root-locale]

Create `getLocale.ts` at your project root. `withGTConfig` detects this file automatically.

```ts title="./getLocale.ts"
import { locale } from 'next/root-params';

export default async function getLocale() {
  return await locale();
}
```

The root parameter supplies the locale without reading request headers or cookies.

## Next steps

- /docs/react/nextjs-quickstart
- /docs/react/nextjs/app-router-static-site-generation
- /docs/react/nextjs/reference/functions/create-next-middleware