NestJS DeepL Module

A NestJS module that provides seamless integration with the DeepL translation API. This module wraps the official DeepL Node.js client and makes it easy to use translation services in your NestJS applications.

Features

• 🔧 Easy Integration: Simple module setup with NestJS dependency injection
• 🌍 Translation Support: Full access to DeepL's translation capabilities
• ⚙️ Configurable: Flexible configuration options for different environments
• 🔒 Type Safe: Built with TypeScript for better development experience
• 📦 Lightweight: Minimal overhead with clean architecture

Installation

npm install nestjs-deepl deepl-node
# or
yarn add nestjs-deepl deepl-node
# or
pnpm add nestjs-deepl deepl-node

Note: This module requires deepl-node as a peer dependency. Make sure to install it alongside nestjs-deepl.

Prerequisites

• Node.js (v18 or higher)
• NestJS framework
• DeepL API key (Get one here)

Quick Start

1. Import the Module

import { Module } from '@nestjs/common';
import { DeepLModule } from 'nestjs-deepl';

@Module({
  imports: [
    DeepLModule.register({
      authKey: 'your-deepl-api-key',
    }),
  ],
})
export class AppModule {}

2. Use the DeepL Client

import { Injectable } from '@nestjs/common';
import { DeepLClient } from 'deepl-node';

@Injectable()
export class TranslationService {
  constructor(private readonly deepLClient: DeepLClient) {}

  async translateText(text: string, targetLang: string) {
    try {
      const result = await this.deepLClient.translateText(
        text,
        null,
        targetLang,
      );
      return result.text;
    } catch (error) {
      throw new Error(`Translation failed: ${error.message}`);
    }
  }
}

Configuration Options

The module accepts all configuration options from the official DeepL Node.js client:

DeepLModule.register({
  authKey: 'your-deepl-api-key',
  serverUrl: 'https://api-free.deepl.com', // Optional: for DeepL Free API
  // Other DeepL client options...
});

Global Module

To make the DeepL client available globally across your application:

DeepLModule.register({
  authKey: 'your-deepl-api-key',
  isGlobal: true,
});

Async Configuration

For dynamic configuration (e.g., from environment variables):

DeepLModule.registerAsync({
  useFactory: (configService: ConfigService) => ({
    authKey: configService.get('DEEPL_API_KEY'),
  }),
  inject: [ConfigService],
});

API Reference

DeepLModule

The main module class that provides the DeepL client.

Static Methods

• register(options: DeepLModuleOptions): Configure the module with static options
• registerAsync(options: DeepLModuleAsyncOptions): Configure the module with async options

DeepLModuleOptions

Extends the official DeepL client options:

interface DeepLModuleOptions extends DeepLClientOptions {
  authKey: string;
}

Examples

Basic Translation

@Injectable()
export class TranslationService {
  constructor(private readonly deepLClient: DeepLClient) {}

  async translateToGerman(text: string) {
    const result = await this.deepLClient.translateText(text, null, 'DE');
    return result.text;
  }
}

Document Translation

@Injectable()
export class DocumentService {
  constructor(private readonly deepLClient: DeepLClient) {}

  async translateDocument(filePath: string, targetLang: string) {
    const result = await this.deepLClient.translateDocument(
      filePath,
      targetLang,
    );
    return result;
  }
}

Usage Statistics

@Injectable()
export class UsageService {
  constructor(private readonly deepLClient: DeepLClient) {}

  async getUsage() {
    const usage = await this.deepLClient.getUsage();
    return usage;
  }
}

Environment Variables

It's recommended to use environment variables for your DeepL API key:

# .env
DEEPL_API_KEY=your-deepl-api-key

// app.module.ts
DeepLModule.register({
  authKey: process.env.DEEPL_API_KEY,
});

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Development Setup

1. Clone the repository
2. Install dependencies: pnpm install
3. Run tests: pnpm test
4. Run linting: pnpm lint
5. Build the project: pnpm build

License

This project is licensed under the MIT License - see the LICENSE file for details.

Author

Xudong Huang

• Email: [email protected]
• Website: https://www.huangxudong.com
• GitHub: @xudongcc

Related Links

• DeepL API Documentation
• DeepL Node.js Client
• NestJS Documentation
• NestJS Module Guide

Support

If you encounter any issues or have questions, please:

1. Check the DeepL API documentation
2. Search existing issues
3. Create a new issue with detailed information

Made with ❤️ for the NestJS community