---
createdAt: 2025-09-09
updatedAt: 2026-05-06
title: Tanstack Start i18n - How to translate an Tanstack Start app in 2026
description: Learn how to add internationalization (i18n) to your Tanstack Start application using Intlayer. Follow this comprehensive guide to make your app multilingual with locale-aware routing.
keywords:
  - Internationalization
  - Documentation
  - Intlayer
  - Tanstack Start
  - React
  - i18n
  - TypeScript
  - Locale Routing
  - Sitemap
slugs:
  - doc
  - environment
  - tanstack-start
applicationTemplate: https://github.com/aymericzip/intlayer-tanstack-start-template
applicationShowcase: https://intlayer-tanstack-start-template.vercel.app
youtubeVideo: https://www.youtube.com/watch?v=_XTdKVWaeqg
history:
  - version: 8.9.0
    date: 2026-05-04
    changes: "Update Solid useIntlayer API usage to direct property access"
  - version: 8.6.0
    date: 2026-03-29
    changes: "Add pre-render & sitemap"
  - version: 7.5.9
    date: 2025-12-30
    changes: "Add init command"
  - version: 7.4.0
    date: 2025-12-11
    changes: "Introduce validatePrefix and add step 14 - Handling 404 pages with localized routes."
  - version: 7.3.9
    date: 2025-12-05
    changes: "Add step 13 - Retrieve the locale in your server actions (Optional)"
  - version: 7.2.3
    date: 2025-11-18
    changes: "Add step 13 - Adapt Nitro"
  - version: 7.1.0
    date: 2025-11-17
    changes: "Fix prefix default by adding getPrefix function useLocalizedNavigate, LocaleSwitcher and LocalizedLink."
  - version: 6.5.2
    date: 2025-10-03
    changes: "Update documentation"
  - version: 5.8.1
    date: 2025-09-09
    changes: "Added for Tanstack Start"
---

# Translate your Tanstack Start website using Intlayer | Internationalization (i18n)

## Table of Contents

<TOC/>

This guide demonstrates how to integrate **Intlayer** for seamless internationalization in Tanstack Start projects with locale-aware routing, TypeScript support, and modern development practices.

## What is Intlayer?

**Intlayer** is an innovative, open-source internationalization (i18n) library designed to simplify multilingual support in modern web applications.

With Intlayer, you can:

- **Easily manage translations** using declarative dictionaries at the component level.
- **Dynamically localize metadata**, routes, and content.
- **Ensure TypeScript support** with autogenerated types, improving autocompletion and error detection.
- **Benefit from advanced features**, like dynamic locale detection and switching.
- **Enable locale-aware routing** with Tanstack Start's file-based routing system.

---

## Step-by-Step Guide to Set Up Intlayer in a Tanstack Start Application

<Tabs defaultTab="video">
  <Tab label="Video" value="video">
  
<iframe title="The best i18n solution for Tanstack Start? Discover Intlayer" class="m-auto aspect-16/9 w-full overflow-hidden rounded-lg border-0" allow="autoplay; gyroscope;" loading="lazy" width="1080" height="auto" src="https://www.youtube.com/embed/_XTdKVWaeqg?autoplay=0&amp;origin=https://intlayer.org&amp;controls=0&amp;rel=1"/>

  </Tab>
  <Tab label="Code" value="code">

<iframe
  src="https://ide.intlayer.org/aymericzip/intlayer-tanstack-start-template?file=intlayer.config.ts"
  className="m-auto overflow-hidden rounded-lg border-0 max-md:size-full max-md:h-[700px] md:aspect-16/9 md:w-full"
  title="Demo CodeSandbox - How to Internationalize your application using Intlayer"
  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
  loading="lazy"
/>

  </Tab>
  <Tab label="Demo" value="demo">

<iframe
  src="https://intlayer-tanstack-start-template.vercel.app"
  className="m-auto overflow-hidden rounded-lg border-0 max-md:size-full max-md:h-[700px] md:aspect-16/9 md:w-full"
  title="Demo - intlayer-tanstack-start-template"
  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
  loading="lazy"
/>

  </Tab>
</Tabs>

See [Application Template](https://github.com/aymericzip/intlayer-tanstack-start-template) on GitHub.

### Step 1: Create Project

Start by creating a new TanStack Start project by following the [Start new project](https://tanstack.com/start/latest/docs/framework/react/quick-start) guide on the TanStack Start website.

### Step 2: Install Intlayer Packages

Install the necessary packages using your preferred package manager:

```bash packageManager="npm"
npm install intlayer react-intlayer
npm install vite-intlayer --save-dev
npx intlayer init
```

```bash packageManager="pnpm"
pnpm add intlayer react-intlayer
pnpm add vite-intlayer --save-dev
pnpm intlayer init
```

```bash packageManager="yarn"
yarn add intlayer react-intlayer
yarn add vite-intlayer --save-dev
yarn intlayer init
```

```bash packageManager="bun"
bun add intlayer react-intlayer
bun add vite-intlayer --dev
bun x intlayer init
```

- **intlayer**

  The core package that provides internationalization tools for configuration management, translation, [content declaration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md), transpilation, and [CLI commands](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/index.md).

- **react-intlayer**
  The package that integrates Intlayer with React application. It provides context providers and hooks for React internationalization.

- **vite-intlayer**
  Includes the Vite plugin for integrating Intlayer with the [Vite bundler](https://vite.dev/guide/why.html#why-bundle-for-production), as well as middleware for detecting the user's preferred locale, managing cookies, and handling URL redirection.

### Step 3: Configuration of your project

Create a config file to configure the languages of your application:

```typescript fileName="intlayer.config.ts"
import type { IntlayerConfig } from "intlayer";

import { Locales } from "intlayer";

const config: IntlayerConfig = {
  internationalization: {
    defaultLocale: Locales.ENGLISH,
    locales: [Locales.ENGLISH, Locales.FRENCH, Locales.SPANISH],
  },
};

export default config;
```

> Through this configuration file, you can set up localized URLs, middleware redirection, cookie names, the location and extension of your content declarations, disable Intlayer logs in the console, and more. For a complete list of available parameters, refer to the [configuration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md).

### Step 4: Integrate Intlayer in Your Vite Configuration

Add the intlayer plugin into your configuration:

```typescript fileName="vite.config.ts"
import { tanstackStart } from "@tanstack/react-start/plugin/vite";
import viteReact from "@vitejs/plugin-react";
import { nitro } from "nitro/vite";
import { defineConfig } from "vite";
import { intlayer } from "vite-intlayer";

const config = defineConfig({
  plugins: [
    nitro(),
    intlayer(),
    tanstackStart({
      router: {
        routeFileIgnorePattern:
          ".content.(ts|tsx|js|mjs|cjs|jsx|json|jsonc|json5)$",
      },
    }),
    viteReact(),
  ],
});

export default config;
```

> The `intlayer()` Vite plugin is used to integrate Intlayer with Vite. It ensures the building of content declaration files and monitors them in development mode. It defines Intlayer environment variables within the Vite application. Additionally, it provides aliases to optimize performance.

### Step 5: Create Root Layout

Configure your root layout to support internationalization by using `useParams` to detect the current locale and setting the `lang` and `dir` attributes on the `html` tag.

```tsx fileName="src/routes/__root.tsx"
import {
  createRootRouteWithContext,
  HeadContent,
  Scripts,
} from "@tanstack/react-router";
import { defaultLocale, getHTMLTextDir } from "intlayer";
import { type ReactNode } from "react";
import { IntlayerProvider } from "react-intlayer";
import { Route as LocaleRoute } from "./{-$locale}/route";

export const Route = createRootRouteWithContext<{}>()({
  head: () => ({
    meta: [
      {
        charSet: "utf-8",
      },
      {
        content: "width=device-width, initial-scale=1",
        name: "viewport",
      },
      {
        title: "TanStack Start Starter",
      },
    ],
  }),

  shellComponent: RootDocument,
});

function RootDocument({ children }: { children: ReactNode }) {
  const params = LocaleRoute.useParams();
  const locale = params?.locale ?? defaultLocale;

  return (
    <html dir={getHTMLTextDir(locale)} lang={locale}>
      <head>
        <HeadContent />
      </head>
      <body>
        <IntlayerProvider locale={locale}>{children}</IntlayerProvider>
        <Scripts />
      </body>
    </html>
  );
}
```

### Step 6: Create Locale Layout

Create a layout that handles the locale prefix and performs validation.

```tsx fileName="src/routes/{-$locale}/route.tsx"
import { createFileRoute, Outlet, redirect } from "@tanstack/react-router";
import { validatePrefix } from "intlayer";

export const Route = createFileRoute("/{-$locale}")({
  beforeLoad: ({ params }) => {
    const localeParam = params.locale;

    // Validate the locale prefix
    const { isValid, localePrefix } = validatePrefix(localeParam);

    if (!isValid) {
      throw redirect({
        to: "/{-$locale}/404",
        params: { locale: localePrefix },
      });
    }
  },
  component: Outlet,
});
```

> Here, `{-$locale}` is a dynamic route parameter that gets replaced with the current locale. This notation makes the slot optional, allowing it to work with routing modes such as `'prefix-no-default'` etc.

> Be aware that this slot may cause issues if you use multiple dynamic segments in the same route (e.g., `/{-$locale}/other-path/$anotherDynamicPath/...`).
> For the `'prefix-all'` mode, you may prefer switching the slot to `$locale` instead.
> For the `'no-prefix'` or `'search-params'` mode, you can remove the slot entirely.

### Step 7: Declare Your Content

Create and manage your content declarations to store translations:

```tsx fileName="src/contents/page.content.ts"
import type { Dictionary } from "intlayer";

import { t } from "intlayer";

const appContent = {
  content: {
    links: {
      about: t({
        en: "About",
        es: "Acerca de",
        fr: "À propos",
      }),
      home: t({
        en: "Home",
        es: "Inicio",
        fr: "Accueil",
      }),
    },
    meta: {
      title: t({
        en: "Welcome to Intlayer + TanStack Router",
        es: "Bienvenido a Intlayer + TanStack Router",
        fr: "Bienvenue à Intlayer + TanStack Router",
      }),
      description: t({
        en: "This is an example of using Intlayer with TanStack Router",
        es: "Este es un ejemplo de uso de Intlayer con TanStack Router",
        fr: "Ceci est un exemple d'utilisation d'Intlayer avec TanStack Router",
      }),
    },
  },
  key: "app",
} satisfies Dictionary;

export default appContent;
```

> Your content declarations can be defined anywhere in your application as soon they are included into the `contentDir` directory (by default, `./app`). And match the content declaration file extension (by default, `.content.{json,ts,tsx,js,jsx,mjs,cjs}`).

> For more details, refer to the [content declaration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md).

### Step 7: Create Locale-Aware Components and Hooks

Create a `LocalizedLink` component for locale-aware navigation:

```tsx fileName="src/components/localized-link.tsx"
import type { FC } from "react";

import { Link, type LinkComponentProps } from "@tanstack/react-router";
import { useLocale } from "react-intlayer";
import { getPrefix } from "intlayer";

export const LOCALE_ROUTE = "{-$locale}" as const;

export type To = StripLocalePrefix<LinkComponentProps["to"]>;

export type StripLocalePrefix<T extends string | undefined> = T extends
  | `/${typeof LOCALE_ROUTE}/`
  | `/${typeof LOCALE_ROUTE}`
  ? "/"
  : T extends `/${typeof LOCALE_ROUTE}/${infer Rest}`
    ? `/${Rest}`
    : T;

type LocalizedLinkProps = {
  to?: To;
} & Omit<LinkComponentProps, "to">;

export const LocalizedLink: FC<LocalizedLinkProps> = (props) => {
  const { locale } = useLocale();
  const { localePrefix } = getPrefix(locale);

  return (
    <Link
      {...props}
      params={{
        locale: localePrefix,
        ...(typeof props?.params === "object" ? props?.params : {}),
      }}
      to={`/${LOCALE_ROUTE}${props.to}` as LinkComponentProps["to"]}
    />
  );
};
```

This component has two objectives:

- Remove the unnecessary `{-$locale}` prefix from the URL.
- Inject the locale parameter into the URL to ensure the user is directly redirected to the localized route.

Then we can create a `useLocalizedNavigate` hook for programmatic navigation:

```tsx fileName="src/hooks/useLocalizedNavigate.tsx"
import { useNavigate } from "@tanstack/react-router";
import { getPrefix } from "intlayer";
import { useLocale } from "react-intlayer";
import type { StripLocalePrefix } from "@/components/localized-link";
import type { FileRouteTypes } from "@/routeTree.gen";

type NavigateFn = ReturnType<typeof useNavigate>;
type BaseNavigateOptions = Parameters<NavigateFn>[0];

type LocalizedTo = StripLocalePrefix<FileRouteTypes["to"]>;

export type LocalizedNavigateOptions = Omit<
  BaseNavigateOptions,
  "to" | "params"
> & {
  to: LocalizedTo;
  params?: Omit<NonNullable<BaseNavigateOptions["params"]>, "locale">;
};

type LocalizedNavigate = (
  options: LocalizedNavigateOptions
) => ReturnType<NavigateFn>;

export const useLocalizedNavigate = () => {
  const navigate = useNavigate();

  const { locale } = useLocale();

  const localizedNavigate: LocalizedNavigate = (args: any) => {
    const { localePrefix } = getPrefix(locale);

    if (typeof args === "string") {
      return navigate({
        to: `/${LOCALE_ROUTE}${args}`,
        params: { locale: localePrefix },
      });
    }

    const { to, ...rest } = args;

    const localizedTo = `/${LOCALE_ROUTE}${to}` as any;

    return navigate({
      to: localizedTo,
      params: { locale: localePrefix, ...rest } as any,
    });
  };

  return localizedNavigate;
};
```

### Step 8: Utilize Intlayer in Your Pages

Access your content dictionaries throughout your application:

#### Localized Home Page

```tsx fileName="src/routes/{-$locale}/index.tsx"
import { createFileRoute } from "@tanstack/react-router";
import { getIntlayer, defaultLocale } from "intlayer";
import { useIntlayer } from "react-intlayer";

import LocaleSwitcher from "@/components/locale-switcher";
import { LocalizedLink } from "@/components/localized-link";
import { useLocalizedNavigate } from "@/hooks/useLocalizedNavigate";

export const Route = createFileRoute("/{-$locale}/")({
  component: RouteComponent,
});

function RouteComponent() {
  const content = useIntlayer("app");
  const navigate = useLocalizedNavigate();

  return (
    <div>
      <div>
        {content.title}
        <LocaleSwitcher />
        <div>
          <LocalizedLink to="/">{content.links.home}</LocalizedLink>
          <LocalizedLink to="/about">{content.links.about}</LocalizedLink>
        </div>
        <div>
          <button onClick={() => navigate({ to: "/" })}>
            {content.links.home}
          </button>
          <button onClick={() => navigate({ to: "/about" })}>
            {content.links.about}
          </button>
        </div>
      </div>
    </div>
  );
}
```

> If you want to use your content in a `string` attribute, such as `alt`, `title`, `href`, `aria-label`, etc., you can use the value of the function, like:
>
> ```html
> <img src="{content.image.src.value}" alt="{content.image.value}" />
> <img src="{content.image.src.toString()}" alt="{content.image.toString()}" />
> <img src="{String(content.image.src)}" alt="{String(content.image)}" />
> ```

> To Learn more about the `useIntlayer` hook, refer to the [documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useIntlayer.md).

### Step 9: Create a Locale Switcher Component

Create a component to allow users to change languages:

```tsx fileName="src/components/locale-switcher.tsx"
import { useLocation } from "@tanstack/react-router";
import {
  getHTMLTextDir,
  getLocaleName,
  getPathWithoutLocale,
  getPrefix,
  Locales,
} from "intlayer";
import type { FC } from "react";
import { useLocale } from "react-intlayer";

import { LocalizedLink, type To } from "./localized-link";

export const LocaleSwitcher: FC = () => {
  const { pathname } = useLocation();

  const { availableLocales, locale, setLocale } = useLocale();

  const pathWithoutLocale = getPathWithoutLocale(pathname);

  return (
    <ol>
      {availableLocales.map((localeEl) => (
        <li key={localeEl}>
          <LocalizedLink
            aria-current={localeEl === locale ? "page" : undefined}
            onClick={() => setLocale(localeEl)}
            params={{ locale: getPrefix(localeEl).localePrefix }}
            to={pathWithoutLocale as To}
          >
            <span>
              {/* Locale - e.g. FR */}
              {localeEl}
            </span>
            <span>
              {/* Language in its own Locale - e.g. Français */}
              {getLocaleName(localeEl, locale)}
            </span>
            <span dir={getHTMLTextDir(localeEl)} lang={localeEl}>
              {/* Language in current Locale - e.g. Francés with current locale set to Locales.SPANISH */}
              {getLocaleName(localeEl)}
            </span>
            <span dir="ltr" lang={Locales.ENGLISH}>
              {/* Language in English - e.g. French */}
              {getLocaleName(localeEl, Locales.ENGLISH)}
            </span>
          </LocalizedLink>
        </li>
      ))}
    </ol>
  );
};
```

> To Learn more about the `useLocale` hook, refer to the [documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useLocale.md).

### Step 10: HTML Attributes Management

As seen in Step 5, you can manage the `lang` and `dir` attributes of the `html` tag using `useParams` in your root component. This ensures that the correct attributes are set on the server and client.

```tsx fileName="src/routes/__root.tsx"
function RootDocument({ children }: { children: ReactNode }) {
  const params = LocaleRoute.useParams();
  const locale = params?.locale ?? defaultLocale;

  return (
    <html dir={getHTMLTextDir(locale)} lang={locale}>
      {/* ... */}
    </html>
  );
}
```

---

### Step 11: Add middleware (Optional)

You can also use the `intlayerProxy` to add server-side routing to your application. This plugin will automatically detect the current locale based on the URL and set the appropriate locale cookie. If no locale is specified, the plugin will determine the most appropriate locale based on the user's browser language preferences. If no locale is detected, it will redirect to the default locale.

> Note that to use the `intlayerProxy` in production, you need to switch the `vite-intlayer` package from `devDependencies` to `dependencies`.

```typescript {7,14-17} fileName="vite.config.ts"
import { tanstackStart } from "@tanstack/react-start/plugin/vite";
import viteReact from "@vitejs/plugin-react";
import { nitro } from "nitro/vite";
import { defineConfig } from "vite";
import { intlayer, intlayerProxy } from "vite-intlayer";

export default defineConfig({
  plugins: [
    intlayerProxy(), // The proxy should be placed before server if you use Nitro
    nitro(),
    intlayer(),
    tanstackStart({
      router: {
        routeFileIgnorePattern:
          ".content.(ts|tsx|js|mjs|cjs|jsx|json|jsonc|json5)$",
      },
    }),
    viteReact(),
  ],
});
```

---

### Step 12: Internationalize your Metadata (Optional)

You can also use the `getIntlayer` hook to access your content dictionaries throughout your application:

```tsx fileName="src/routes/{-$locale}/index.tsx"
import { createFileRoute } from "@tanstack/react-router";
import { getIntlayer } from "intlayer";

export const Route = createFileRoute("/{-$locale}/")({
  component: RouteComponent,
  head: ({ params }) => {
    const { locale } = params;
    const path = "/"; // The path for this route

    const metaContent = getIntlayer("app", locale);

    return {
      links: [
        // Canonical link: Points to the current localized page
        { rel: "canonical", href: getLocalizedUrl(path, locale) },

        // Hreflang: Tell Google about all localized versions
        ...localeMap(({ locale: mapLocale }) => ({
          rel: "alternate",
          hrefLang: mapLocale,
          href: getLocalizedUrl(path, mapLocale),
        })),

        // x-default: For users in unmatched languages
        // Define the default fallback locale (usually your primary language)
        {
          rel: "alternate",
          hrefLang: "x-default",
          href: getLocalizedUrl(path, defaultLocale),
        },
      ],
      meta: [
        { title: metaContent.title },
        { name: "description", content: metaContent.meta.description },
      ],
    };
  },
});
```

---

### Step 13: Retrieve the locale in your server actions (Optional)

You may want to access the current locale from inside your server actions or API endpoints.
You can do this using the `getLocale` helper from `intlayer`.

Here's an example using TanStack Start's server functions:

```tsx fileName="src/routes/{-$locale}/index.tsx"
import { createServerFn } from "@tanstack/react-start";
import {
  getRequestHeader,
  getRequestHeaders,
} from "@tanstack/react-start/server";
import { getCookie, getIntlayer, getLocale } from "intlayer";

export const getLocaleServer = createServerFn().handler(async () => {
  const locale = await getLocale({
    // Get the cookie from the request (default: 'INTLAYER_LOCALE')
    getCookie: (name) => {
      const cookieString = getRequestHeader("cookie");

      return getCookie(name, cookieString);
    },
    // Get the header from the request (default: 'x-intlayer-locale')
    // Fallback using Accept-Language negotiation
    getHeader: (name) => getRequestHeader(name),
  });

  // Retrieve some content using getIntlayer()
  const content = getIntlayer("app", locale);

  return { locale, content };
});
```

---

### Step 14: Manage not found pages (Optional)

When a user visits a non-existing page, you can display a custom not found page and the locale prefix may impact the way the not found page is triggered.

#### Understanding TanStack Router's 404 Handling with Locale Prefixes

In TanStack Router, handling 404 pages with localized routes requires a multi-layered approach:

1. **Dedicated 404 route**: A specific route to display the 404 UI
2. **Route-level validation**: Validates locale prefixes and redirects invalid ones to 404
3. **Catch-all route**: Captures any unmatched paths within the locale segment

```tsx fileName="src/routes/{-$locale}/404.tsx"
import { createFileRoute } from "@tanstack/react-router";

// This creates a dedicated /[locale]/404 route
// It's used both as a direct route and imported as a component in other files
export const Route = createFileRoute("/{-$locale}/404")({
  component: NotFoundComponent,
});

// Exported separately so it can be reused in notFoundComponent and catch-all routes
export function NotFoundComponent() {
  return (
    <div>
      <h1>404</h1>
    </div>
  );
}
```

```tsx fileName="src/routes/{-$locale}/route.tsx"
import { createFileRoute, Outlet, redirect } from "@tanstack/react-router";
import { validatePrefix } from "intlayer";
import { NotFoundComponent } from "./404";

export const Route = createFileRoute("/{-$locale}")({
  // beforeLoad runs before the route renders (on both server and client)
  // It's the ideal place to validate the locale prefix
  beforeLoad: ({ params }) => {
    const localeParam = params.locale;

    // validatePrefix checks if the locale is valid according to your intlayer config
    const { isValid, localePrefix } = validatePrefix(localeParam);

    if (!isValid) {
      // Invalid locale prefix - redirect to the 404 page with a valid locale prefix
      throw redirect({
        to: "/{-$locale}/404",
        params: { locale: localePrefix },
      });
    }
  },
  component: Outlet,
  // notFoundComponent is called when a child route doesn't exist
  // e.g., /en/non-existent-page triggers this within the /en layout
  notFoundComponent: NotFoundComponent,
});
```

```tsx fileName="src/routes/{-$locale}/$.tsx"
import { createFileRoute } from "@tanstack/react-router";

import { NotFoundComponent } from "./404";

// The $ (splat/catch-all) route matches any path that doesn't match other routes
// e.g., /en/some/deeply/nested/invalid/path
// This ensures ALL unmatched paths within a locale show the 404 page
// Without this, unmatched deep paths might show a blank page or error
export const Route = createFileRoute("/{-$locale}/$")({
  component: NotFoundComponent,
});
```

### (Optional) Step 15: Extract the content of your components

If you have an existing codebase, transforming thousands of files can be time-consuming.

To ease this process, Intlayer propose a [compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md) / [extractor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md) to transform your components and extract the content.

To set it up, you can add a `compiler` section in your `intlayer.config.ts` file:

```typescript fileName="intlayer.config.ts" codeFormat={["typescript", "esm", "commonjs"]}
import { type IntlayerConfig } from "intlayer";

const config: IntlayerConfig = {
  // ... Rest of your config
  compiler: {
    /**
     * Indicates if the compiler should be enabled.
     */
    enabled: true,

    /**
     * Defines the output files path
     */
    output: ({ fileName, extension }) => `./${fileName}${extension}`,

    /**
     * Indicates if the components should be saved after being transformed.
     *
     * - If `true`, the compiler will rewrite the component file in the disk. So the transformation will be permanent, and the compiler will skip the transformation for the next process. That way, the compiler can transform the app, and then it can be removed.
     *
     * - If `false`, the compiler will inject the `useIntlayer()` function call into the code in the build output only, and keep the base codebase intact. The transformation will be done only in memory.
     */
    saveComponents: false,

    /**
     * Dictionary key prefix
     */
    dictionaryKeyPrefix: "",
  },
};

export default config;
```

<Tabs>
 <Tab value='Extract command'>

Run the extractor to transform your components and extract the content

```bash packageManager="npm"
npx intlayer extract
```

```bash packageManager="pnpm"
pnpm intlayer extract
```

```bash packageManager="yarn"
yarn intlayer extract
```

```bash packageManager="bun"
bun x intlayer extract
```

 </Tab>
 <Tab value='Babel compiler'>

Update your `vite.config.ts` to include the `intlayerCompiler` plugin:

```ts fileName="vite.config.ts"
import { defineConfig } from "vite";
import { intlayer, intlayerCompiler } from "vite-intlayer";

export default defineConfig({
  plugins: [
    intlayer(),
    intlayerCompiler(), // Adds the compiler plugin
  ],
});
```

```bash packageManager="npm"
npm run build # Or npm run dev
```

```bash packageManager="pnpm"
pnpm run build # Or pnpm run dev
```

```bash packageManager="yarn"
yarn build # Or yarn dev
```

```bash packageManager="bun"
bun run build # Or bun run dev
```

 </Tab>
</Tabs>

---

### Step 16: Pre-render & Generate Sitemap (Optional)

Intlayer comes with a built-in sitemap generator to help you create a sitemap for your application easily. It handles localized routes and adds the necessary metadata for search engines.

> The Intlayer generated sitemap supports the `xhtml:link` namespace (Hreflang XML Extensions). Unlike the default sitemap generators that only list raw URLs, Intlayer automatically creates the required bidirectional links between all language versions of a page (e.g., `/about`, `/about?lang=fr`, and `/about?lang=es`). This ensures search engines correctly index and serve the right language version to the right audience.

To use it, you first need to configure your `vite.config.ts` to enable pre-rendering for your localized routes and disable the default TanStack Start sitemap generation.

```typescript fileName="vite.config.ts"
import { localeFlatMap } from "intlayer";
// ... other imports

export const pathList = ["", "/about", "/404"];

const localizedPages = localeFlatMap(({ urlPrefix }) =>
  pathList.map((path) => ({
    path: `${urlPrefix}${path}`,
    prerender: {
      enabled: true,
    },
  }))
);

export default defineConfig({
  plugins: [
    // ... other plugins
    tanstackStart({
      // ... other config
      sitemap: {
        enabled: false,
      },
      prerender: {
        enabled: true,
        crawlLinks: false,
        concurrency: 10,
      },
      pages: localizedPages,
    }),
  ],
});
```

Then, create a `src/routes/sitemap[.]xml.ts` route that uses the `generateSitemap` function:

```typescript fileName="src/routes/sitemap[.]xml.ts"
import { createFileRoute } from "@tanstack/react-router";
import { generateSitemap } from "intlayer";

const SITE_URL = (
  import.meta.env.VITE_SITE_URL ?? "http://localhost:3000"
).replace(/\/$/, "");

export const Route = createFileRoute("/sitemap.xml")({
  server: {
    handlers: {
      GET: async () => {
        const sitemap = generateSitemap(
          [
            { path: "/", changefreq: "daily", priority: 1.0 },
            { path: "/about", changefreq: "monthly", priority: 0.8 },
          ],
          { siteUrl: SITE_URL }
        );

        return new Response(sitemap, {
          headers: { "Content-Type": "application/xml" },
        });
      },
    },
  },
});
```

---

### Step 17: Configure TypeScript (Optional)

Intlayer uses module augmentation to get benefits of TypeScript and make your codebase stronger.

Ensure your TypeScript configuration includes the autogenerated types:

```json5 fileName="tsconfig.json"
{
  // ... your existing configurations
  include: [
    // ... your existing includes
    ".intlayer/**/*.ts", // Include the auto-generated types
  ],
}
```

---

### Git Configuration

It is recommended to ignore the files generated by Intlayer. This allows you to avoid committing them to your Git repository.

To do this, you can add the following instructions to your `.gitignore` file:

```plaintext fileName=".gitignore"
# Ignore the files generated by Intlayer
.intlayer
```

---

## VS Code Extension

To improve your development experience with Intlayer, you can install the official **Intlayer VS Code Extension**.

[Install from the VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=intlayer.intlayer-vs-code-extension)

This extension provides:

- **Autocompletion** for translation keys.
- **Real-time error detection** for missing translations.
- **Inline previews** of translated content.
- **Quick actions** to easily create and update translations.

For more details on how to use the extension, refer to the [Intlayer VS Code Extension documentation](https://intlayer.org/doc/vs-code-extension).

---

## Go Further

To go further, you can implement the [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md) or externalize your content using the [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md).

---

## Documentation References

- [Intlayer Documentation](https://intlayer.org)
- [Tanstack Start Documentation](https://reactrouter.com/)
- [useIntlayer hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useIntlayer.md)
- [useLocale hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useLocale.md)
- [Content Declaration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md)
- [Configuration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md)
