LinkCaster

A Chrome Extension for seamless image link conversion and cloud uploads

LinkCaster transforms how you work with images online. Convert screenshot links from services like Lightshot into permanent, shareable URLs on your preferred cloud storage. Upload images and videos directly to Google Drive, Catbox, or vgy.me with a single click.

Key Features

Link Conversion

• Batch Processing - Convert multiple image links simultaneously
• Smart Detection - Automatically extracts direct image URLs from Lightshot pages
• Multiple Destinations - Upload to Catbox.moe, vgy.me, or Google Drive
• Parallel Processing - Concurrent uploads with intelligent rate limiting

Image Uploads

• Folder Monitoring - Auto-detect new screenshots from selected folders
• Time Filtering - Show only files from the last N minutes
• Batch Selection - Upload multiple images with one click
• Upload History - Track all uploads with one-click link copying

Video Uploads

• Google Drive Integration - Direct video uploads with auto-generated shareable links
• Large File Support - Handles videos up to Google Drive's limits
• Progress Tracking - Real-time upload progress indicators

Tech Stack

Layer	Technology
Frontend	Vanilla JavaScript (ES6 Modules), HTML5, CSS3
Extension	Chrome Manifest V3, Service Workers
Backend	Node.js, Express.js
Cloud APIs	Google Drive API, Catbox.moe API, vgy.me API
Storage	Chrome Storage API, IndexedDB
Deployment	Railway (backend)

Architecture

LinkCaster/
├── manifest.json           # Chrome extension manifest (MV3)
├── background.js           # Service worker for API calls & OAuth
├── popup.html/css          # Extension popup UI
├── js/
│   ├── popup.js            # Main entry point
│   └── modules/            # ES6 module architecture
│       ├── convertTab.js       # Link conversion logic
│       ├── uploadImageTab.js   # Image upload handling
│       ├── uploadVideoTab.js   # Video upload handling
│       ├── uploadServices.js   # Cloud service integrations
│       ├── storage.js          # Chrome storage abstraction
│       ├── fileMonitoring.js   # File System Access API
│       └── ...
└── backend/
    └── server.js           # OAuth proxy & token refresh

Design Decisions

• Manifest V3 - Future-proof architecture using service workers instead of background pages
• ES6 Modules - Clean separation of concerns with explicit imports/exports
• IndexedDB for File Handles - Persist folder access permissions across sessions
• Token Refresh Locking - Prevents race conditions during OAuth token refresh
• Exponential Backoff - Graceful retry logic for failed uploads

Installation

From Source

1. Clone the repository

   git clone https://github.com/yourusername/LinkCaster.git

2. Open Chrome and navigate to chrome://extensions/

3. Enable Developer mode (top right toggle)

4. Click Load unpacked and select the LinkCaster folder

5. The extension icon will appear in your browser toolbar

Backend Setup (for Google Drive)

1. Navigate to the backend directory

   cd backend
   npm install

2. Create a .env file with your Google OAuth credentials

   GOOGLE_CLIENT_ID=your_client_id
   GOOGLE_CLIENT_SECRET=your_client_secret
   GOOGLE_REDIRECT_URI=your_redirect_uri

3. Start the server

   npm start

Usage

Converting Links

1. Click the LinkCaster icon in your browser toolbar
2. Paste image links into the text area (one per line or space-separated)
3. Select your destination service (Catbox, vgy.me, or Google Drive)
4. Click Replace Links
5. Copy the converted URLs from the output

Uploading Images

1. Switch to the Upload Img tab
2. Either:
   • Select a folder to monitor for new screenshots, or
   • Use the file picker to select images directly
3. Check the files you want to upload
4. Click Upload

Supported Link Types

Service	Example URL
Lightshot	https://prnt.sc/abc123
Direct Images	https://example.com/image.png
Direct Videos	https://example.com/video.mp4

API Configuration

vgy.me

1. Create an account at vgy.me
2. Get your user key from Account Details
3. Enter the key in LinkCaster settings

Google Drive

1. Click Connect to Google Drive in the extension
2. Authorize the application
3. Files upload to a LinkCaster folder in your Drive

Development

Building for Distribution

python scripts/build/build.py

This creates a build/ directory with the packaged extension.

Project Structure

Directory	Purpose
js/modules/	Core business logic as ES6 modules
backend/	OAuth proxy server for Google Drive
docs/user/	End-user documentation
scripts/build/	Build automation

Privacy

• No data collection - All processing happens locally in your browser
• No tracking - No analytics or telemetry
• Minimal permissions - Only requests permissions necessary for functionality
• Secure OAuth - Tokens stored locally, never transmitted to third parties

Contributing

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

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

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