# General Translation React SDKs (gt-react, gt-next, gt-react-native): gtMiddleware
URL: https://generaltranslation.com/en-US/docs/react/tanstack-start/reference/functions/gt-middleware.mdx
Docs index: https://generaltranslation.com/llms.txt
Description: Create request-scoped locale state for TanStack Start server functions. API reference for gtMiddleware.

The `gtMiddleware` export is global TanStack Start request middleware. Import it from `gt-tanstack-start` and register it before calling runtime helpers on the server.

## Overview [#overview]

```ts title="src/start.ts"
import { createCsrfMiddleware, createStart } from '@tanstack/react-start';
import { gtMiddleware } from 'gt-tanstack-start';

const csrfMiddleware = createCsrfMiddleware({
  filter: ({ handlerType }) => handlerType === 'serverFn',
});

export const startInstance = createStart(() => ({
  requestMiddleware: [csrfMiddleware, gtMiddleware],
}));
```

## How it works [#how-it-works]

- Resolves the locale, region, and internationalization setting from the incoming request and your General Translation configuration.
- When `localeRouting` is enabled, prioritizes the first supported path segment over the locale cookie and `Accept-Language` header. The default locale remains unprefixed.
- Respects TanStack Router's base path through `TSS_ROUTER_BASEPATH`.
- Stores those values in request-local state for server-side rendering, server routes, and server functions.
- Keeps request state isolated during concurrent server requests.
- Persists the resolved locale in the General Translation locale cookie.

Call [`initializeGT`](/docs/react/reference/config#initialize) from `gt-tanstack-start` before the middleware handles a request. The middleware throws if initialization has not created its condition store.

## Server helpers [#server-helpers]

The middleware provides request state to:

- [`getLocale`](/docs/react/tanstack-start/reference/functions/get-locale)
- [`getEnableI18n`](/docs/react/tanstack-start/reference/functions/get-enable-i18n)
- [`getGT`](/docs/react/tanstack-start/reference/functions/get-gt)
- [`getMessages`](/docs/react/tanstack-start/reference/functions/get-messages)
- [`getTranslations`](/docs/react/tanstack-start/reference/functions/get-translations)

These helpers are isomorphic. Their server branches throw when called outside the active middleware request scope; their client branches read the browser condition store initialized by [`initializeGT`](/docs/react/reference/config#initialize).

## Version history [#version-history]

| Version | Changes |
| --- | --- |
| `11.1.5` | Exported `gtMiddleware` from the root browser condition so setup files can use the root import in client builds. |

## Sitemap

See the full [sitemap](https://generaltranslation.com/sitemap.md) for all pages.