CapyLinker

CapyLinker is an intelligent link management Android app powered by Google's Gemini AI. Save, organize, and analyze your bookmarks with AI-generated summaries and smart tagging.

✨ Features

🤖 AI-Powered Analysis

• Automatic Summarization: Gemini AI analyzes web content and generates concise summaries
• Smart Tagging: Automatically extracts relevant keywords and tags from content
• Title Extraction: Intelligent title generation based on content analysis
• YouTube Video Analysis: Specialized support for YouTube videos with automatic title, description, and thumbnail extraction
• Multi-language Support: AI responds in your preferred language

📱 Core Functionality

• Quick Link Saving: Add links via in-app dialog or share menu
• Clipboard Auto-Detection: Automatically detects URLs in clipboard when opening the app (can be toggled in settings)
• Background Processing: Links are analyzed asynchronously without blocking the UI
• Visual Thumbnails: Automatically extracts and displays Open Graph images or representative thumbnails for each link
• QR Code Generation: Generate and share a QR code for any link, complete with an embedded app icon.
• Unified Search: Search across titles, summaries, URLs, and tags with real-time filtering
• Tag Filtering: Filter saved links by tags for easy organization
• Expandable Cards: Tap to expand/collapse full summaries
• Link Options Menu: Long-press on any link to access quick actions:
  • Open: Launch URL in default browser
  • Copy URL: Copy link to clipboard
  • Share: Share link via system share menu
  • Share as QR Code: Share a QR code image of the link.
  • Re-summarize: Re-run Gemini analysis to get a fresh summary
  • Delete: Remove link from collection

🌍 Multi-language Support

The app supports 10 languages with full UI translation:

• English
• Korean (한국어)
• Japanese (日本語)
• Simplified Chinese (简体中文)
• Traditional Chinese (繁體中文)
• Spanish (Español)
• French (Français)
• German (Deutsch)
• Russian (Русский)
• Portuguese (Português)

💾 Data Management

• Backup & Restore: Export all your data (links, settings, API key) to a JSON file
• Complete Backup: Single file contains everything - links, summaries, tags, thumbnails, and all settings
• Easy Migration: Transfer your data between devices or create safety backups
• Timestamped Backups: Automatic filename with date and time (e.g., capyLinker-backup-202501151430.json)

🎨 Customization

• Theme Options: System default, Light mode, or Dark mode
• Language Settings: Choose your preferred language (10 languages supported)
• Gemini Model Selection: Choose between Gemini 2.5 Flash Lite, Flash, or Pro models
• Clipboard Auto-Add: Toggle automatic URL detection from clipboard
• Persistent Settings: All preferences are saved locally

🔒 Privacy & Security

• 100% Local Storage: All your links, summaries, and tags are stored exclusively on your device
• No Cloud Sync: Your data never leaves your device (backup files are stored locally)
• No Account Required: Use the app without any registration or login
• No Analytics: We don't track or collect any user data
• Secure API Key Storage: API keys are encrypted using Android Keystore
• User-Controlled Backups: Backup files are created only when you request them and stored where you choose
• Open Source: Full transparency - inspect the code yourself

Your Privacy Matters: CapyLinker is designed with privacy-first principles. The only external communication is with Google's Gemini API for content analysis, and only when you explicitly save a link. Backup files are JSON format and stored locally - you have complete control over your data.

📸 Screenshots

🚀 Getting Started

Prerequisites

• Android device/emulator running Android 15 (API 35) or higher
• Android Studio (for development)
• Google Gemini API key (free tier available)

Installation

1. Clone the repository

   git clone https://github.com/yourusername/capylinker.git
   cd capylinker

2. Open in Android Studio

   • Launch Android Studio
   • Select "Open an Existing Project"
   • Navigate to the cloned repository

3. Build and Run

   • Sync Gradle files
   • Connect your Android device or start an emulator
   • Click "Run" or press Shift + F10

Setting Up Gemini API

CapyLinker requires a Google Gemini API key to enable AI-powered features.

1. Get Your API Key

1. Visit Google AI Studio
2. Sign in with your Google account
3. Click "Get API Key" or "Create API Key"
4. Copy your API key (starts with AIza...)

2. Configure in App

1. Open CapyLinker app
2. Tap the Settings icon (⚙️) in the top right
3. Scroll to "Gemini API Configuration"
4. Paste your API key in the text field
5. Select your preferred Gemini model:
   • Gemini 2.5 Flash Lite (Default): Fastest, best for most use cases
   • Gemini 2.5 Flash: Balanced speed and quality
   • Gemini 2.5 Pro: Highest quality, slower but more detailed analysis
6. Tap "Save API Key"

💡 Tip: The free tier allows 15 requests per minute. If you hit the rate limit, the app automatically retries after a short delay.

API Key Storage & Privacy

• ✅ Your API key is stored locally on your device only
• ✅ Encrypted using Android's secure DataStore
• ✅ Never transmitted to any server except Google Gemini API
• ✅ Never shared with third parties
• ✅ You can delete it anytime from Settings

What data is sent to Gemini API?

• Only the URL content when you save a link for analysis
• For YouTube videos: video title, description, and metadata
• Your language preference (to get responses in your language)
• Nothing else - no personal data, no usage statistics

YouTube Video Support

CapyLinker has special handling for YouTube links:

• Automatically detects YouTube URLs (youtu.be, youtube.com/watch, youtube.com/embed)
• Extracts video title and description from YouTube metadata
• Displays high-quality video thumbnail
• Gemini AI analyzes the video information to generate summary and tags
• Works seamlessly like any other link

📖 Usage Guide

Adding Links

Method 1: In-App

1. Tap the + (Floating Action Button)
2. Enter the URL
3. Tap "Save"
4. The link is analyzed in the background

Method 2: Share Menu

1. In any browser or app, tap the Share button
2. Select "CapyLinker" from the share menu
3. The link is automatically saved and analyzed

Method 3: Clipboard Auto-Detection

1. Copy any URL to your clipboard
2. Open CapyLinker
3. A dialog will appear asking if you want to add the URL
4. Tap "Add" to save the link
   • Can be disabled in Settings if not needed

Finding & Organizing Links

Unified Search

1. Tap the 🔍 Search icon in the top bar
2. Type your search query
3. Results filter in real-time across:
   • Link titles
   • Summaries
   • URLs
   • Tags
4. Press back or tap ✕ to exit search mode

Filtering by Tags

• Tap any tag chip at the top of the screen
• Only links with that tag will be displayed
• Tap "All" to show all links
• Search and tag filters work together for precise results

Viewing Details

• Tap a link card to expand/collapse the full summary
• Thumbnails are displayed automatically for visual recognition
• Long press to open the Link Options Menu

Link Options Menu

Long-press any link to access quick actions:

• Open: Opens the URL in your default browser
• Copy URL: Copies the link to clipboard
• Share: Share via system share menu
• Share as QR Code: Share a QR code image of the link.
• Re-summarize: Re-run Gemini analysis to get a fresh summary
• Delete: Removes the link from your collection

Backup & Restore

Creating a Backup

1. Open Settings (⚙️)
2. Scroll to "Backup & Restore" section
3. Tap "Create Backup"
4. Choose a location to save the backup file
5. Your backup file is created with timestamp: capyLinker-backup-YYYYMMDDHHMM.json

What's included in the backup?

• All saved links with titles, summaries, and tags
• Thumbnail URLs
• Gemini API key
• Selected Gemini model
• Language preference
• Theme setting
• Clipboard auto-add preference

Restoring from Backup

1. Open Settings (⚙️)
2. Scroll to "Backup & Restore" section
3. Tap "Restore Backup"
4. Select your backup JSON file
5. All data will be restored and overwrite existing data

• A success message will appear when complete

⚠️ Warning: Restoring a backup will replace all existing data. Make sure to create a backup of your current data before restoring if you want to keep it.

Use Cases for Backup:

• 📱 Device Migration: Moving to a new phone
• 🔄 Multiple Devices: Keep data in sync across devices
• 💾 Safety Backup: Regular backups to prevent data loss
• 🧪 Testing: Try different configurations without losing data

Managing Settings

Navigate to Settings (⚙️) to customize:

• Language: Choose your preferred language (10 languages available)
• Theme: Light, Dark, or System default
• Clipboard Auto-Add: Enable/disable automatic URL detection
• Gemini Model: Select which AI model to use for analysis
• API Key: Update or change your Gemini API key
• Backup & Restore: Export or import your data

Back Button Behavior

For a better user experience:

• In Search Mode: Back button exits search
• In Link List: Press back twice within 2 seconds to exit the app
  • First press shows a toast message
  • Second press closes the app
• With Dialogs Open: Back button closes the dialog