# node: initializeGT
URL: https://generaltranslation.com/en-GB/docs/node/api/initialize-gt.mdx
---
title: initializeGT
description: API reference for the initializeGT setup function
---

## Overview

The `initializeGT` function configures General Translation for use in a Node.js runtime.
It must be called once before any translation functions are used.

```js
import { initializeGT } from 'gt-node';

initializeGT({
  defaultLocale: 'en-US',
  locales: ['en-US', 'es', 'fr'],
  projectId: 'your-project-id',
});
```

<Callout type="warn">
  **Required setup:**
  `initializeGT` must be called before using `withGT`, `getGT`, `getMessages`, `getTranslations`, or any other translation function.
  Call it once during your server&#39;s initialisation (e.g. at the top of your entry file).
</Callout>

## Reference

### Parameters

<TypeTable
  type={{
"defaultLocale?": {
type: 'string',
optional: true,
default: "'en-US'",
},
"locales?": {
type: 'string[]',
optional: true,
},
"projectId?": {
type: 'string',
optional: true,
},
"devApiKey?": {
type: 'string',
optional: true,
},
"cacheUrl?": {
type: 'string | null',
optional: true,
},
"runtimeUrl?": {
type: 'string | null',
optional: true,
},
"dictionary?": {
type: 'Dictionary',
optional: true,
},
"loadDictionary?": {
type: 'DictionaryLoader',
optional: true,
},
"loadTranslations?": {
type: 'TranslationsLoader',
optional: true,
},
"customMapping?": {
type: 'Record<string, string | Partial<LocaleProperties>>',
optional: true,
},
"enableI18n?": {
type: 'boolean',
optional: true,
},
"cacheExpiryTime?": {
type: 'number',
optional: true,
},
}}
/>

### Description

| Prop               | Description                                                                                               |
| ------------------ | --------------------------------------------------------------------------------------------------------- |
| `defaultLocale`    | The default locale for your application. Defaults to `'en-US'`.                                           |
| `locales`          | An array of locale codes your application supports.                                                       |
| `projectId`        | Your General Translation project ID, required for cloud translation services.                             |
| `devApiKey`        | API key for on-demand translations in the development environment.                                        |
| `cacheUrl`         | URL of the GT cache service. Set to `null` to disable.                                                    |
| `runtimeUrl`       | URL of the GT runtime translation service. Set to `null` to disable.                                      |
| `dictionary`       | A source-language dictionary object for use with [`getTranslations`](/docs/node/api/get-translations).    |
| `loadDictionary`   | An async function that loads a translated dictionary for a given locale. Requires `dictionary` to be set. |
| `loadTranslations` | A custom function to load translations from your own source.                                              |
| `customMapping`    | A mapping of custom locale codes to standard locale codes or locale properties.                           |
| `enableI18n`       | Whether to enable i18n features.                                                                          |
| `cacheExpiryTime`  | Time in milliseconds before cached translations expire.                                                   |

### Returns

`void`

***

## Examples

### Basic setup

```js title="server.js"
import { initializeGT } from 'gt-node';

initializeGT({
  defaultLocale: 'en-US',
  locales: ['en-US', 'es', 'fr', 'ja'],
  projectId: process.env.GT_PROJECT_ID,
});
```


### With a custom translation loader

```js title="server.js"
import { initializeGT } from 'gt-node';

initializeGT({
  defaultLocale: 'en-US',
  locales: ['en-US', 'es'],
  loadTranslations: async (locale) => {
    const res = await fetch(`https://my-api.com/translations/${locale}`);
    return res.json();
  },
});
```

***


## Notes

* `initializeGT` must be called **once** before any translation functions are used.
* If using GT cloud services, provide `projectId`. For development, also provide `devApiKey`.
* The `loadTranslations` option lets you bring your own translation source instead of using GT&#39;s CDN.

## Next steps

* See [`withGT`](/docs/node/api/with-gt) to provide locale context for each request.
* See [`getGT`](/docs/node/api/get-gt) and [`getMessages`](/docs/node/api/get-messages) for translating inline strings.
* See [`getTranslations`](/docs/node/api/get-translations) for dictionary-based translations.