MCP ScreenCatch

An MCP (Model Context Protocol) server that provides screen capture functionality for Claude Desktop, emulating Windows Snipping Tool capabilities.

Overview

MCP ScreenCatch enables Claude Desktop to capture screenshots of user-selected screen regions. The tool allows users to highlight areas of their monitor(s), capture them, and save the images with timestamps for easy retrieval and processing.

Objectives

• Seamless Integration: Provide an MCP command that Claude Desktop can invoke to initiate screen captures
• Interactive Selection: Allow users to select specific regions of their screen(s) using a familiar snipping interface
• Multi-Monitor Support: Work across multiple monitors for flexible screen capture
• Sequential Captures: Enable users to capture multiple screenshots in succession without restarting the tool
• Timestamped Files: Automatically timestamp each capture for chronological ordering
• Configurable Output: Let users specify the output directory for captured images
• Pipeline Ready: Save files in a location accessible to other MCP commands or external applications

Features

Core Functionality

• Region Selection: Click and drag interface to select screen regions
• Capture & Save: Button/icon to finalize and save the selected region
• Continuous Mode: After each capture, prompt user to:
  • Capture another screenshot
  • Quit the tool
• Timestamp Naming: Files named with ISO 8601 timestamps (e.g., capture_2025-11-27_064730.png)
• Directory Selection: User-configurable output directory

Use Cases

• Capture UI elements for debugging
• Document visual workflows
• Create sequential tutorials or guides
• Feed captured images to Claude for analysis
• Build visual documentation pipelines

Technical Implementation

MCP Protocol

The tool will be exposed as an MCP server that Claude Desktop can connect to, providing:

• Tool: capture_screen - Initiates the screen capture interface
• Tool: set_output_directory - Configure where captures are saved
• Tool: list_captures - Retrieve timestamped capture files

Technology Stack

• Language: TypeScript/Node.js
• MCP SDK: @modelcontextprotocol/sdk
• Screen Capture: screenshot-desktop for cross-platform screen capture
• Image Processing: Sharp for image cropping and manipulation
• UI Framework: Electron for transparent overlay and region selection

File Format

• Default format: PNG (lossless, good for UI captures)
• Naming convention: capture_YYYY-MM-DD_HHMMSS.png
• Metadata: Optional JSON sidecar with capture timestamp and dimensions

Installation

npm install
npm run build

Configuration

Add to Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "screencatch": {
      "command": "node",
      "args": ["/path/to/mcp-screencatch/build/index.js"]
    }
  }
}

Usage

From Claude Desktop

Once configured, you can ask Claude to capture screenshots:

Claude, can you capture a screenshot of my screen?

Interactive Overlay

1. An Electron overlay window will appear covering your screen(s)
2. Click and drag to select the region you want to capture
3. Click the Capture button or press Enter to save
4. Press ESC or click Cancel to abort
5. The captured image is saved with a timestamp

Available Commands

Capture a screenshot:

Claude, capture a screenshot

Set output directory:

Claude, set the screenshot output directory to C:\Users\johne\screenshots

List recent captures:

Claude, list my recent screenshots

File Naming

Screenshots are automatically named with ISO 8601 timestamps:

• capture_2025-11-27_143052.png
• capture_2025-11-27_143105.png

This ensures chronological ordering and prevents filename conflicts.

Development Status

✅ Implemented - Core functionality complete

• ✅ MCP server with stdio transport
• ✅ Interactive region selection with Electron overlay
• ✅ Timestamped file naming
• ✅ Configurable output directory
• ✅ List and manage captures
• ⚠️ Note: Requires Electron, which adds ~150MB to node_modules. For production use, consider electron-builder for packaging.

Future Enhancements

• Support for full screen and window captures
• Multiple image format options (PNG, JPG, WebP)
• Annotation tools (arrows, text, highlights)
• Clipboard integration
• Automatic cleanup of old captures
• Screenshot comparison tools

License

MIT

Contributing

Contributions welcome! Please open an issue or submit a pull request.