TxtSync

macOS menubar app that makes your screen readable by AI

Extracting text from windows via OCR, accessible through MCP (Model Context Protocol)

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Overview

TxtSync is a lightweight menubar application that monitors selected windows and provides their text content to AI assistants like Claude Code via the Model Context Protocol (MCP).

Key Features:

• On-demand OCR - Only processes when AI requests, saving CPU & battery
• Multi-window support - Monitor multiple windows simultaneously
• Japanese & English - Full support for both languages
• Native macOS - Built with SwiftUI and Vision framework

How It Works

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│   Your Screen   │────▶│    TxtSync      │────▶│   Claude Code   │
│  (Slack, etc.)  │     │  (Vision OCR)   │     │   (via MCP)     │
└─────────────────┘     └─────────────────┘     └─────────────────┘

1. Select windows to monitor from the menubar
2. AI requests window content through MCP
3. TxtSync captures and OCRs the window (~1.5s)
4. Text is returned to AI for analysis

Installation

Build from Source

# Clone
git clone https://github.com/tomohiro-owada/TxtSync.git
cd TxtSync

# Build
./scripts/build.sh

# Create app bundle
./scripts/bundle.sh

# Install
cp -r TxtSync.app /Applications/

First Launch

1. Open TxtSync from Applications
2. Grant Screen Recording permission when prompted
3. Select windows to monitor from the menubar

Note: If window titles don't appear, reset permissions:

tccutil reset ScreenCapture com.txtsync.app

Then relaunch TxtSync and grant permission again.

Claude Code Integration

Add to your MCP configuration (~/.claude.json):

{
  "mcpServers": {
    "txtsync": {
      "command": "/Applications/TxtSync.app/Contents/MacOS/TxtSyncMCP"
    }
  }
}

Available Tools

Tool	Description
list_windows	List monitored windows with IDs and titles
get_window_text	Get OCR text from a specific window
get_all_text	Get OCR text from all monitored windows
search_text	Search for text across all windows
get_window_screenshot	Save window screenshot to temp file (JPEG compressed for large images)

Example Usage

You: What's in my Slack?

Claude: [calls get_window_text with app_name="Slack"]
        Your Slack shows a thread in #general with messages about...

You: Search for "error" in my terminal

Claude: [calls search_text with query="error"]
        Found "error" in Ghostty window: "npm ERR! code ENOENT..."

Architecture

TxtSync/
├── Sources/
│   ├── TxtSync/           # Menubar app (SwiftUI)
│   │   ├── App/           # Entry point, state management
│   │   ├── Views/         # UI components
│   │   ├── Models/        # Data structures
│   │   ├── Services/      # Window management, permissions
│   │   └── Theme/         # Styling
│   └── TxtSyncMCP/        # MCP server (JSON-RPC over stdio)
├── Resources/
│   └── Info.plist
└── scripts/
    ├── build.sh
    └── bundle.sh

Requirements

• macOS 13.0 (Ventura) or later
• Screen Recording permission
• ~50MB disk space

Performance

Metric	Value
Idle CPU	< 1%
OCR latency	~1.5 seconds
Memory	~70MB

Privacy

• Local only - All processing happens on your Mac
• No network - No data sent anywhere
• You control - Only monitors windows you explicitly select

License

MIT License - see LICENSE for details.

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Built with Vision Framework and MCP

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