JSON Translation AI (JTA)

A CLI tool that automatically synchronizes and translates JSON translation files using multiple AI providers including OpenAI GPT, Anthropic Claude, and Google Gemini models. Perfect for maintaining consistent translations across multiple languages in your i18n projects.

✨ Features

🔒 Privacy & Security

• 100% Private: Your content never stored except communication with AI providers.
• Secure API Keys: Your API keys are only used for translation requests, never stored. If you still worried, use a specific key and disable it.

💰 Cost-Effective AI Models

• Smart Model Selection: Choose from cost-effective models like Claude Haiku, GPT-4o Mini, and Gemini Flash.
• Intelligent Caching: Use cache first to avoid re-translating existing content to minimize API costs
• Batch Processing: Optimize API usage with efficient batch translations
• Performance Presets: Configure for your API limits

🚀 Advanced Translation Features

• Multi-File Structure Support: Organize translations in folders with multiple JSON files per language
• Flexible Key Structures: Full support for both nested and flattened JSON key structures
• Multi-Format Language Support: Supports both 2-letter (ISO 639-1) and 4-letter (ISO 639-1 + ISO 3166-1) language codes
• Locale-Specific Translations: Handle regional variants like en-US, zh-TW, es-MX, fr-CA for precise localization
• Folder Structure Preservation: Maintains exact folder structure across all target languages
• Concurrent File Processing: Process multiple files per language simultaneously
• Custom System Messages: Provide specific context for better translation quality
• Parallel Processing: Multi-language processing with configurable concurrency
• Fallback Strategy: Automatic fallback to individual translations if batch processing fails
• Progress Tracking: Real-time progress bars and detailed logging for scheduling tasks
• Comprehensive Reporting: Detailed reports on translation success, failures, and missing keys

🚀 Quick Start

1. Installation

npm install -g json-translated-ai

2. Configure OpenRouter

Set your OpenRouter(only OpenRouter tested currently) API key and proxy URL in your environment or .env file:

PROVIDER_KEY=your_openrouter_api_key_here
PROVIDER_PROXY_URL=https://openrouter.ai/api/v1

3. Run Translation

# Specify a custom folder, assume en.json in locales folder
jta --folder ./locales

# Specify a language file, language codes (2-letter or 4-letter) in each line
jta --languages languages.txt

# Use a specific AI model
jta --model anthropic/claude-3-haiku
jta --model google/gemini-2.5-flash

# Use performance preset
jta --preset FAST

# Specify API key and proxy URL directly
jta --key your_openrouter_key --url https://openrouter.ai/api/v1

📁 Multi-File Structure Support

The tool now supports organizing translations in multiple JSON files per language, making it perfect for large projects with organized translation structures.

Single-File Structure (Legacy - Still Supported)

locales/
├── en.json
├── es.json
└── zh-TW.json

Multi-File Structure (New Feature)

locales/
├── en/
│   ├── home.json
│   ├── products.json
│   ├── auth.json
│   └── common.json
├── es/
│   ├── home.json
│   ├── products.json
│   ├── auth.json
│   └── common.json
└── zh-TW/
    ├── home.json
    ├── products.json
    ├── auth.json
    └── common.json

Nested Folder Structure

locales/
├── en/
│   ├── pages/
│   │   ├── home.json
│   │   └── products.json
│   ├── components/
│   │   ├── auth.json
│   │   └── common.json
│   └── admin/
│       └── dashboard.json
├── es/
│   ├── pages/
│   │   ├── home.json
│   │   └── products.json
│   ├── components/
│   │   ├── auth.json
│   │   └── common.json
│   └── admin/
│       └── dashboard.json
└── zh-TW/
    ├── pages/
    │   ├── home.json
    │   └── products.json
    ├── components/
    │   ├── auth.json
    │   └── common.json
    └── admin/
        └── dashboard.json

Usage

Simply run the tool with your multi-file structure:

# Multi-file structure - automatically detected
jta --folder ./locales

# Single-file structure - still works as before
jta --folder ./locales

The system will:

• ✅ Automatically detect whether you're using single-file or multi-file structure
• ✅ Maintain the exact folder structure in target languages

🔄 Updated Keys Feature

The tool supports marking keys as updated in template files using __updated_keys__ arrays. When a key is marked as updated, it will be re-translated in all target language files, even if it already exists.

Usage

Add __updated_keys__ arrays to your template objects(deepest) to mark keys that need re-translation:

{
  "hero": {
    "title": "Welcome to Our Platform",
    "subtitle": "The best solution for your needs",
    "cta": "Get Started",
    "__updated_keys__": ["title"]
  },
  "common": {
    "loading": "Loading...",
    "error": "An error occurred",
    "success": "Success!",
    "__updated_keys__": ["error", "success"]
  }
}

Key Benefits

• Selective Updates: Only re-translate keys that have been updated
• Cost Efficiency: Avoid re-translating unchanged content
• Precise Control: Mark exactly which keys need updates
• Nested Support: Works with deeply nested object structures

Best Practices

• Add __updated_keys__ only to objects where updates occur
• Remove __updated_keys__ arrays after translation is complete

🌐 Custom Template Language Support

The tool supports using any language as the template language, not just English. This is useful when your primary language is not English or when you want to use a specific regional variant.

Usage

Specify a custom template language using the --template or -t option:

# Use Spanish as template language
jta --template es

# Use British English as template
jta --template en-GB

# Use French (France) as template
jta --template fr-FR

# Use German as template
jta --template de

Supported Template Languages

The tool supports both 2-letter and 4-letter language codes:

• 2-letter codes: en, es, fr, de, it, pt, nl, ru, ja, ko, zh, ar, etc.
• 4-letter codes: en-US, en-GB, es-ES, es-MX, fr-FR, fr-CA, de-DE, de-AT, etc.

How It Works

• Fallback: If no template language is found, it falls back to English (en)

Examples

# Single-file structure with Spanish template
locales/
├── es.json          # Template (Spanish)
├── en.json          # Target language
└── fr.json          # Target language

jta --template es

# Multi-file structure with French template
locales/
├── fr-FR/           # Template (French France)
│   ├── home.json
│   └── products.json
├── en/              # Target language
│   ├── home.json
│   └── products.json
└── de/              # Target language
    ├── home.json
    └── products.json

jta --template fr-FR

🤖 Supported AI Models

We select the most Cost-effective or capable models for translation.

OpenAI Models

• openai/gpt-4o-mini ⭐💰 - Cost-effective GPT-4 model (default)
• openai/gpt-4.1 💰💰 - Latest GPT-4 model with improved performance
• openai/gpt-4o 💰💰 - Fast and efficient GPT-4 model

Anthropic Models

• anthropic/claude-3.5-sonnet ⭐💰💰 - Claude model with excellent performance
• anthropic/claude-3-haiku ⭐💰 - Fast and cost-effective Claude model

Google Models

• google/gemini-2.5-flash ⭐💰 - Fast and efficient Gemini model

🎯 Usage Examples

jta -h

Combine options

# Combine options
jta --folder ./locales --languages languages.txt --model anthropic/claude-3-haiku --preset FAST --system "E-commerce website translations" --cache /path/to/custom-cache.json

Short options are supported.

⚙️ Configuration

Performance Presets

| Preset | Concurrent Languages | Batch Size | Use Case | | -------------- | -------------------- | ---------- | ---------------------------------------- | | CONSERVATIVE | 2 | 1 | Low API limits, safe processing | | BALANCED | 5 | 4 | Good balance of speed and safety | | FAST | 8 | 5 | High API limits, aggressive optimization |

📊 Output

The tool provides comprehensive output including:

• Progress Tracking: Real-time progress bars for languages and batches
• Translation Logs: Detailed logs of each translation operation
• Success Reports: Summary of completed translations
• Failure Reports: Detailed report of failed translations
• Cache Statistics: Information about cache hits and misses

🔧 Advanced Features

Notes

• The tool automatically handles arrays with dot notation indexing.

Language-Specific Processing

Each language code on a line for languages.txt. Supports both 2-letter and 4-letter codes:

# Process specific languages (2-letter codes)
echo "es\nfr\nde" > languages.txt

# Process specific languages (4-letter locale codes)
echo "en-US\nzh-TW\nes-MX" > languages.txt

# Mix both formats
echo "es\nen-US\nzh-TW\nfr-CA" > languages.txt

jta --languages languages.txt

Supported Language Code Formats

2-letter codes (ISO 639-1):

• es - Spanish
• fr - French

4-letter codes (ISO 639-1 + ISO 3166-1):

• en-US - American English
• en-GB - British English
• zh-TW - Traditional Chinese (Taiwan)
• zh-CN - Simplified Chinese (China)

The system automatically recognizes the appropriate language name for translation context.

Custom System Messages

You can provide custom context for better translation quality:

# Mobile app UI translations
jta --system "Translate for mobile app UI with friendly, casual tone"

# E-commerce website
jta --system "E-commerce website translations, professional and trustworthy tone"

# Gaming application
jta --system "Gaming app translations, exciting and engaging tone"

# Technical documentation
jta --system "Technical documentation, precise and clear terminology"

The system message is prepended to the default translation instructions, allowing you to specify:

• Target audience (users, developers, customers)
• Tone and style (casual, professional, friendly, technical)
• Context (mobile app, website, documentation, gaming)
• Special requirements (brand voice, industry terminology)

🚨 Troubleshooting

Common Issues

1. API Key Not Found

   • Ensure PROVIDER_KEY is set in environment or .env file
   • Ensure PROVIDER_PROXY_URL is set to your OpenRouter proxy URL

2. Model Not Supported

   • Check available models with jta --help
   • Ensure you're using a supported model ID

3. OpenRouter Connection Issues

   • Verify PROVIDER_PROXY_URL is set to https://openrouter.ai/api/v1
   • Check network connectivity to OpenRouter endpoint
   • Ensure your OpenRouter API key is valid and has sufficient credits

4. Language Code Issues

   • Mix both formats in your languages.txt file as needed

🤝 Contributing

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

📄 License

This project is licensed under the Apache License 2.0.

💼 Support & Hiring

If this project is helpful to you, please help by sharing this tool or hiring me(I need a job) or using our services. Learn more about me. I, just like you are, need to support a family.

🙏 Acknowledgments

• The open-source community for various dependencies