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DeepL MCP Server

Provides translation and language listing via DeepL API for MCP clients.

typescript

3stars

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Installation

Add the following to your MCP client configuration file.

Configuration

View docs

{
    "mcpServers": {
        "deepl_translator": {
            "command": "node",
            "args": [
                "/path/to/your/deepl-mcp-server/build/index.js"
            ],
            "env": {
                "DEEPL_API_KEY": "YOUR_DEEPL_API_KEY"
            }
        }
    }
}

You set up this MCP server to access DeepL translation capabilities from your tools and assistants. It exposes translation and language listing endpoints, enabling you to translate text strings or fetch supported languages through a simple MCP interface.

How to use

To use the server from an MCP client, connect to the server you configured (deepl-translator) and invoke the available tools. You can translate text strings by calling the translate_text tool with the text you want to translate and a target language, and you can retrieve the list of supported languages with the list_languages tool.

What you can accomplish with the two tools: - Translate one or more text strings into a target language, optionally specifying the source language. DeepL will handle the translation and return the results. - Retrieve the list of languages that the DeepL API supports for translation, either as potential source languages, target languages, or both depending on the request.

How to install

Prerequisites you need before starting:
- Node.js and npm or yarn installed on your system.
- A DeepL API key with access to the translation API.

Step 1: Clone the project repository and enter the folder.

git clone https://github.com/watchdealer-pavel/deepl-mcp-server.git
cd deepl-mcp-server

Step 2: Install dependencies using npm or yarn.

npm install
# or
# yarn install

Step 3: Build the server to produce the runnable index.

npm run build
```
This compiles the TypeScript sources into JavaScript in the build/ directory, with the main entry at build/index.js.

Step 4: Run the server locally and provide your DeepL API key via an environment variable.

DEEPL_API_KEY=YOUR_DEEPL_API_KEY node build/index.js
```
This starts the server locally and makes it available for MCP clients to connect using the configured environment variable.

Configuration and usage notes

You must supply your DeepL API key in the DEEPL_API_KEY environment variable. Your MCP client configurations will point to the server executable and pass this variable to enable authenticated translation requests.

If you are using an MCP client that stores server configurations, you can add the following entries to connect to the local server. The examples assume the compiled server is accessible at the specified path.

"deepl-translator": {
  "command": "node",
  "args": ["/path/to/your/deepl-mcp-server/build/index.js"],
  "env": {
    "DEEPL_API_KEY": "YOUR_DEEPL_API_KEY"
  },
  "disabled": false,
  "alwaysAllow": []
}

Notes on tools and capabilities

The server provides two main tools you can call via MCP: - translate_text translates one or more text strings into a target language, optionally including the source language. - list_languages returns the languages supported by the DeepL API for translation.

Troubleshooting and tips

If translation results are missing or the server does not respond, verify that the DEEPL_API_KEY environment variable is set correctly in the running process and that the server process is the one started from the compiled build/index.js file.

Available tools

translate_text

Translates one or more input strings into a specified target language, optionally using a provided source language. Returns translated text for each input string.

list_languages

Returns the list of supported source or target languages from the DeepL API, allowing you to discover available translation options.