🌍 i18n-agent MCP Client

Professional translation service client for Claude, Cursor, VS Code, Antigravity, and other AI IDEs using the Model Context Protocol (MCP).

npm version

✨ Features

• 🎯 Smart Translation: Context-aware translations with cultural adaptation
• 📁 File Translation: Support for JSON, YAML, CSV, XML, Markdown, and more
• ⚡ Large File Support: Async processing for files >50KB with progress tracking
• 🔄 Timeout Improvements: Extended timeouts (5-10 min) for large translations
• 📊 Progress Tracking: Real-time job status and completion monitoring
• 💰 Credit Tracking: Real-time credit balance and word count estimates
• 🌐 48 Languages: Comprehensive language support with regional variants
• 🔧 Easy Setup: One-command installation for major AI IDEs

🚀 Quick Installation

npx @i18n-agent/mcp-client install

The installer will detect all available AI IDEs and configure them automatically.

Claude Code Marketplace Installation

For Claude Code users, you can install directly from the marketplace:

Step 1: Get your API key

• Visit app.i18nagent.ai
• Sign up or log in
• Copy your API key (starts with "i18n_")

Step 2: Set environment variable

echo 'export I18N_AGENT_API_KEY=your-api-key-here' >> ~/.zshrc
source ~/.zshrc

Replace your-api-key-here with your actual API key.

Step 3: Install from marketplace

/plugin marketplace add i18n-agent/mcp-client
/plugin install i18n-agent@i18n-agent

Step 4: Restart Claude Code

That's it! The plugin will automatically use your API key from the environment variable.

🔑 Setup API Key

1. Get your API key from app.i18nagent.ai

2. Set environment variable:

   bash

   export I18N_AGENT_API_KEY=your-api-key-here
   

3. Make it permanent (add to ~/.bashrc or ~/.zshrc):

   bash

   echo 'export I18N_AGENT_API_KEY=your-api-key-here' >> ~/.zshrc
   

4. Restart your AI IDE to load the new configuration

🎮 Usage Examples

Text Translation

Translate "Hello, how are you?" to Spanish for a casual audience

File Translation

Translate this JSON file to French, preserving the structure

Credit Check

Check my translation credits

Language Support

List supported languages with quality ratings

Content Analysis

Analyze "Hello world! This is a test." for translation to Spanish

🛠 Supported AI IDEs

Note: The installer automatically detects your platform and uses the correct config paths.

🌐 Language Support (48 Languages)

• bg: Bulgarian
• ca: Catalan
• cs: Czech
• da: Danish
• de: German
• el: Greek
• en: English
• en-AU: English (Australia)
• en-CA: English (Canada)
• en-GB: English (United Kingdom)
• en-US: English (United States)
• es: Spanish
• es-MX: Spanish (Mexico)
• et: Estonian
• fi: Finnish
• fr: French
• fr-CA: French (Canada)
• hi: Hindi
• hr: Croatian
• hu: Hungarian
• id: Indonesian
• is: Icelandic
• it: Italian
• ja: Japanese
• ko: Korean
• lt: Lithuanian
• lv: Latvian
• ms: Malay
• nl: Dutch
• no: Norwegian
• pl: Polish
• pt: Portuguese
• pt-BR: Portuguese (Brazil)
• ro: Romanian
• ru: Russian
• sk: Slovak
• sl: Slovenian
• sr: Serbian
• sv: Swedish
• th: Thai
• tl: Filipino
• tr: Turkish
• uk: Ukrainian
• vi: Vietnamese
• zh-Hans: Chinese (Simplified)
• zh-Hant-HK: Chinese (Traditional, Hong Kong)
• zh-Hant-TW: Chinese (Traditional, Taiwan)

📁 Supported File Formats

🔧 Manual Setup

If auto-installation fails, you can manually configure your IDE:

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "i18n-agent": {
      "command": "node",
      "args": ["/path/to/i18n-agent.js"],
      "env": {
        "MCP_SERVER_URL": "https://mcp.i18nagent.ai",
        "I18N_AGENT_API_KEY": "your-api-key-here"
      }
    }
  }
}

Cursor / VS Code

Create .cursor/mcp_settings.json or .vscode/mcp_settings.json:

{
  "mcpServers": {
    "i18n-agent": {
      "command": "node", 
      "args": ["/path/to/i18n-agent.js"],
      "env": {
        "MCP_SERVER_URL": "https://mcp.i18nagent.ai",
        "I18N_AGENT_API_KEY": "your-api-key-here"
      }
    }
  }
}

💡 Usage Tips

Translation Context

• Target Audience: Specify "technical", "casual", "formal", or "general"
• Industry Context: Use "technology", "healthcare", "finance", "education"
• Regional Variations: Add regions like "Spain", "Mexico", "Brazil"

File Translation

• Preserve Structure: Keeps original file format and structure
• Output Format: Convert between formats (JSON ↔ YAML ↔ CSV)
• Large Files: Automatically chunks large files for processing
• Async Processing: Files >50KB processed asynchronously with job tracking
• Progress Monitoring: Real-time status updates for long-running translations
• Timeout Resilience: Up to 10 minutes for large translation jobs

Large Translation Handling

• Async Processing: >100 texts or >50KB files processed asynchronously
• Job Tracking: Unique job IDs for monitoring long-running translations
• Progress Updates: Real-time completion percentages and status
• Extended Timeouts: 5-10 minute timeouts prevent interruptions
• Automatic Polling: Client automatically polls for job completion

Credit Management

• Cost: 1 credit per word ($0.01/word)
• Monitoring: Check balance before large translations
• Estimates: Get word count estimates before translation

Quality Warnings

• Source Analysis: By default, source content is analyzed for quality issues before translation
• Skip Warnings: Use skipWarnings: true to bypass warnings in automated workflows
• Trade-off: Skipping warnings may reduce translation quality as potential issues aren't addressed
• Best Practice: Keep warnings enabled (default) for production translations

🚨 Troubleshooting

Installation Issues

Permission denied:

sudo npm install -g @i18n-agent/mcp-client

IDE not detected:

# Check if IDE directory exists
ls ~/Library/Application\ Support/Claude/
ls ~/.cursor/
ls ~/.vscode/

MCP Connection Issues

"Failed" status in Claude Code:

This usually happens with Node Version Managers (nvm, fnm, n). The installer now automatically detects nvm and creates a wrapper script. If you still have issues:

1. Check your Node installation:

   bash

   which node
   # If output contains .nvm, you're using nvm
   

2. Manual wrapper script (if auto-detection fails): Create ~/.claude/run-mcp.sh:

   bash

   #!/bin/bash
   export PATH="$(dirname $(which node)):$PATH"
   cd ~/.claude
   exec node node_modules/@i18n-agent/mcp-client/i18n-agent.js
   

   Make it executable:

   bash

   chmod +x ~/.claude/run-mcp.sh
   

3. Update Claude configuration: Edit ~/.claude.json:

   json

   {
     "mcpServers": {
       "i18n-agent": {
         "command": "/Users/YOUR_USERNAME/.claude/run-mcp.sh",
         "env": {
           "MCP_SERVER_URL": "https://mcp.i18nagent.ai",
           "I18N_AGENT_API_KEY": "your-api-key"
         }
       }
     }
   }
   

4. Restart Claude Code completely (not just close window, quit the app)

Runtime Issues

API Key not found:

echo $I18N_AGENT_API_KEY  # Should show your key
export I18N_AGENT_API_KEY=your-key-here

Connection errors:

• Check your internet connection
• Verify API key is valid
• Try again after a few seconds

Translation quality:

• Use Tier 1 languages for production
• Add context with industry/audience parameters
• Review Tier 2/3 translations manually

📊 Pricing

• Pay-per-use: 1 credit per word ($0.01/word)
• No subscriptions: Only pay for what you translate
• Bulk discounts: Available for enterprise usage
• Free tier: New accounts get starter credits

🔐 Privacy & Security

• No data storage: Translations are processed in real-time
• Encrypted transport: All data sent over HTTPS
• API key security: Keys are stored locally, never transmitted in logs
• GDPR compliant: EU privacy standards

🏗️ Architecture

The MCP client installer uses a modular architecture for bulletproof installation:

lib/
├── config-manager.js      # Config file operations with atomic writes
├── installer-core.js      # Installation orchestration
├── transport-detector.js  # Auto-detect SSE vs stdio transport
└── validator.js          # Input validation and sanitization

Key Features

• Atomic Config Writes: Use temp files + rename for crash safety
• Automatic Backups: Create timestamped backups before modifications
• Transport Detection: Auto-detect SSE vs stdio from config
• Comprehensive Validation: Validate all inputs at module boundaries
• Zero External Dependencies: Uses only Node.js built-ins

Architecture Details

See detailed documentation:

• Module Architecture - Module responsibilities and design
• Full Architecture Guide - Complete system design

🤝 Contributing

We welcome contributions! Please see our Contributing Guidelines.

Development Setup

git clone https://github.com/i18n-agent/mcp-client.git
cd mcp-client
npm install
npm test

Publishing

Use the publishing script with built-in test gate:

./scripts/publish-mcp-client.sh --dry-run  # Preview package
./scripts/publish-mcp-client.sh            # Run pre-publish checks
npm publish                                 # Publish to npm

📝 License

MIT License - see LICENSE file for details.

Copyright (c) 2025 FatCouple OÜ

🔗 Links

• Website: i18nagent.ai
• Dashboard: app.i18nagent.ai
• Documentation: docs.i18nagent.ai
• GitHub: github.com/i18n-agent/mcp-client
• Issues: github.com/i18n-agent/mcp-client/issues

🆘 Support

• Email: support@i18nagent.ai
• Documentation: docs.i18nagent.ai

🔧 Available MCP Tools

translate_text

Translate text content with cultural adaptation and context awareness.

Parameters:

• texts (array): Array of strings to translate
• targetLanguage (string): Target language code
• targetAudience (string): Target audience context
• industry (string): Industry context
• namespace (string, optional): Optional namespace identifier for backend tracking and project organization
• sourceLanguage (string, optional): Source language (auto-detected if not provided)
• region (string, optional): Specific region for localization
• skipWarnings (boolean, optional): Skip source text quality warnings (default: false). ⚠️ WARNING: May hurt translation quality by bypassing source analysis. Only use when confident about content quality or in automated workflows.

translate_file

Translate files while preserving structure and format.

Parameters:

• filePath or fileContent (string): File path or content to translate
• fileType (string): File format (json, yaml, xml, csv, txt, md, etc.)
• targetLanguage (string): Target language code
• namespace (string, required): Unique namespace identifier for backend tracking and project organization
• preserveKeys (boolean): Whether to preserve object keys/structure
• outputFormat (string): Output format (same, json, yaml, txt)
• skipWarnings (boolean, optional): Skip source text quality warnings (default: false). ⚠️ WARNING: May hurt translation quality by bypassing source analysis. Only use when confident about content quality or in automated workflows.

analyze_content

Analyze content for translation readiness and get improvement suggestions before translation. This helps identify potential issues and optimize content before spending credits on translation.

Parameters:

• content (string/array/object): Content to analyze
• targetLanguage (string): Target language for translation
• fileType (string, optional): File type if content is from a file
• sourceLanguage (string, optional): Source language (auto-detected)
• industry (string): Industry context
• targetAudience (string): Target audience
• region (string, optional): Specific region for localization

Returns:

• Source language detection with confidence score
• Content type and tone analysis
• Translation readiness score (0-100)
• Specific improvement suggestions
• Quality metrics and issues
• Warnings for potential problems
• Estimated credits required

list_supported_languages

Get list of all supported languages with quality ratings.

Parameters:

• includeQuality (boolean): Include quality ratings (default: true)

get_credits

Check remaining translation credits and word count estimates.

Parameters:

• apiKey (string): Your API key

check_translation_status

Check status of async translation jobs (for large files).

Parameters:

• jobId (string): Job ID from async translation

Made with ❤️ by FatCouple OÜ