Rosetta

🚀 Rosetta

An AI-powered Excel translation CLI that translates Excel files while preserving formatting, formulas, and data integrity.

🚀 Quick Start

Rosetta is an AI - powered CLI tool that translates Excel files using Claude AI. It ensures that formulas, formatting, and other elements in the Excel files remain intact during the translation process.

✨ Features

• Translate all text in Excel files using Claude AI without breaking formulas, calculations, formatting, merged cells, charts, images, dropdown menus, and rich text.
• Support for specifying source and target languages, output file names, specific sheets to translate, and adding context for better translations.
• Provide a web application and REST API for browser - based translations with real - time progress tracking.
• Integrate with MCP for both Claude Desktop and Claude Web.

📦 Installation

Install from PyPI:

pip install rosetta-xl

Then set your API key:

# Linux/macOS
export ANTHROPIC_API_KEY=sk-ant-your-key-here

# Windows (Command Prompt)
set ANTHROPIC_API_KEY=sk-ant-your-key-here

# Windows (PowerShell)
$env:ANTHROPIC_API_KEY="sk-ant-your-key-here"

Or create a .env file in your working directory:

ANTHROPIC_API_KEY=sk-ant-your-key-here

💻 Usage Examples

Basic Usage

# Translate to French
rosetta input.xlsx -t french

# Translate to Spanish with custom output name
rosetta input.xlsx -t spanish -o translated.xlsx

# Specify source language (auto-detected by default)
rosetta input.xlsx -s english -t german

# Translate only specific sheets
rosetta input.xlsx -t french --sheets "Sheet1" --sheets "Data"

# Add context for better translations (e.g., domain-specific terms)
rosetta input.xlsx -t french -c "Medical terminology document"

Advanced Usage

Translate a price list to multiple languages:

rosetta prices.xlsx -t french -o prices_fr.xlsx
rosetta prices.xlsx -t german -o prices_de.xlsx
rosetta prices.xlsx -t spanish -o prices_es.xlsx

Translate a medical form with context:

rosetta patient_form.xlsx -t french -c "Medical intake form with clinical terminology"

Translate only the "Questions" sheet:

rosetta survey.xlsx -t japanese --sheets "Questions"

📚 Documentation

Options

Troubleshooting

⚠️ Important Note

"ANTHROPIC_API_KEY not set":

• Make sure you've exported the key: export ANTHROPIC_API_KEY=sk-ant-...
• Or create a .env file with the key

⚠️ Important Note

"Invalid API key":

• Check that your key starts with sk-ant-
• Make sure you copied the full key from console.anthropic.com

⚠️ Important Note

"Rate limit exceeded":

• You've hit Anthropic's rate limits. Wait a minute and try again
• Or reduce batch size: rosetta input.xlsx -t french -b 20

How it works

1. Extracts all text cells from your Excel file
2. Sends text to Claude AI for translation (in batches)
3. Writes translations back, preserving all formatting
4. Saves the translated file

Your original file is never modified.

Web App & API

Rosetta also includes a web application and REST API for browser - based translations.

Running the API server

# Install with uv (recommended)
uv sync

# Start the server
uv run uvicorn rosetta.api:app --reload

# Or with pip
pip install -e .
uvicorn rosetta.api:app --reload

The API runs at http://localhost:8000 by default.

Running the frontend

cd frontend
npm install
npm run dev

The frontend runs at http://localhost:5173 and connects to the API.

API Endpoints

Real-time Progress

The /translate-stream endpoint uses Server - Sent Events (SSE) to stream translation progress in real - time. The frontend automatically falls back to the standard /translate endpoint on networks that don't support SSE (e.g., corporate proxies).

MCP Integration

Rosetta includes MCP (Model Context Protocol) servers for both Claude Desktop and Claude Web.

For Claude Desktop (Local)

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "rosetta": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/rosetta", "python", "-m", "rosetta.api.mcp"],
      "env": {
        "ANTHROPIC_API_KEY": "your-key-here"
      }
    }
  }
}

Usage: Use local file paths for best results.

Translate ~/Downloads/report.xlsx to French

For Claude Web (Browser)

⚠️ Important Note

Claude.ai does not yet support custom MCP servers in the browser (as of January 2026).

💡 Usage Tip

Current recommendation: Use the web app for browser - based translations.

See MCP_USAGE.md for detailed instructions.

🔧 Technical Details

Prerequisites

You need a Claude API key from Anthropic.

1. Go to console.anthropic.com
2. Create an account (or sign in)
3. Go to API Keys and create a new key
4. Copy the key (starts with sk-ant-...)

⚠️ Important Note

API usage is billed by Anthropic. See anthropic.com/pricing for current rates. Translating a typical Excel file costs a few cents.

Requirements

• Python 3.11+
• Anthropic API key

📄 License

MIT