DeepLX-translation-proxy

This is a proxy server designed specifically to securely forward translation requests to the DeepLX API. It acts as an intermediary to protect your DeepLX API key, preventing its exposure in client-side code.

The server is configured with a strict CORS policy, allowing requests only from specified origins.

How It Works

1. The server exposes a single POST /translate endpoint.
2. A client application sends a request to this endpoint with the text to be translated, the source language, and the target language.
3. The proxy server retrieves the secret DEEPLX_API_KEY from its environment variables.
4. It then forwards the translation request, including the secret key, to the https://api.deeplx.org/translate API.
5. Finally, it returns the response from the DeepLX API directly to the client.

Deploy Your Own

You can deploy your own instance to Vercel with one click:

API Endpoint

POST /translate

Forwards a translation request to the DeepLX API.

Request Body:

{
  "text": "Hello, world!",
  "source_lang": "EN",
  "target_lang": "ZH"
}

Success Response:

The JSON response from the DeepLX API.

Error Response:

If the request fails, the server-side API key is not configured, or input validation fails, it returns a 400 or 500 status code with a JSON body:

{
  "error": "Error message",
  "details": "Optional additional details or validation errors"
}

Configuration

To function correctly, the server requires the following environment variables. You can set these variables in your deployment environment, or by creating a .env file in the project root:

• DEEPLX_API_KEY: Your secret DeepLX API key.

  DEEPLX_API_KEY=your_secret_deeplx_api_key
  

• ALLOWED_ORIGINS: A comma-separated list of allowed CORS origins (e.g., https://example.com,http://localhost:8080).

  ALLOWED_ORIGINS=https://example.com,http://localhost:3000
  

• RATE_LIMIT_MAX: (Optional) The maximum number of requests allowed per IP per 15 minutes. Default is 100 if not set.

  RATE_LIMIT_MAX=200
  

Running Locally

1. Install dependencies:

   npm install

2. Run the server (make sure to replace your_api_key and your_allowed_origins with your actual values):

   DEEPLX_API_KEY=your_api_key ALLOWED_ORIGINS=your_allowed_origins npm start

   The server will start on port 3000.

Deployment

This project is configured for easy deployment as a serverless function on Vercel. The vercel.json file handles the necessary build and routing configurations.