GT Constructor
API Reference for the GT class constructor
Overview
The GT constructor creates a new instance of the General Translation class, which provides access to all translation, formatting, and locale functionality.
import { GT } from 'generaltranslation';
const gt = new GT({
  apiKey: 'your-api-key',
  projectId: 'your-project-id',
  sourceLocale: 'en',
  targetLocale: 'es'
});The constructor will automatically check the environment for GT_API_KEY and GT_PROJECT_ID environment variables, so you can omit them from the constructor parameters.
Additionally, it will validate all provided locale codes.
Reference
Parameters
Prop
Type
The GTConstructorParams object supports the following properties:
| Property | Type | Optional | Description | 
|---|---|---|---|
| apiKey | string | ✓ | Production API key for translation service | 
| devApiKey | string | ✓ | Development API key (takes precedence in development) | 
| projectId | string | ✓ | Unique project identifier | 
| sourceLocale | string | ✓ | Default source locale for translations | 
| targetLocale | string | ✓ | Default target locale for translations | 
| locales | string[] | ✓ | Array of supported locale codes | 
| baseUrl | string | ✓ | Custom API base URL (for enterprise deployments) | 
| customMapping | CustomMapping | ✓ | Custom locale code mappings and definitions | 
Returns
A new GT class instance with all translation and locale methods available.
Examples
Basic Usage
import { GT } from 'generaltranslation';
// Minimal setup - uses environment variables
const gt = new GT();With API Credentials
const gt = new GT({
  projectId: 'my-project-id',
  apiKey: 'my-api-key',
  targetLocale: 'fr'
});With Custom Locale Mapping
A custom mapping can be provided. This lets the user (1) use aliases for locale codes which, (2) can override the standard BCP 47 validation, and (3) override the standard BCP 47 locale information.
For example, say you wanted to use cn as an alias for zh.
Because the General Translation API does not support cn, you must specify a custom mapping.
const gt = new GT({
  projectId: 'my-project-id',
  apiKey: 'my-api-key',
  targetLocale: 'es',
  customMapping: {
    'cn': { code: 'zh' }
  }
});You can do other things with custom mappings, such as add custom names, emojis, etc.
const gt = new GT({
  projectId: 'my-project-id',
  apiKey: 'my-api-key',
  targetLocale: 'es',
  customMapping: { 'en-US': { name: 'Mandarin', emoji: '🇫🇷' } }
});Notes
- All parameters are optional, but API operations will require apiKeyandprojectId
- The constructor validates all locale codes immediately, throwing errors for invalid codes
- Custom mappings take precedence over standard BCP 47 validation
Next Steps
- Configure your instance with setConfig
- Start translating with translate
- Learn about GTConstructorParamstype
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