Modern Cross-Platform Screen Capture and Annotation Tool
A high-performance screen capture tool built with .NET 10 and Avalonia UI, featuring intelligent overlay system, comprehensive annotation capabilities, and cross-platform support.
π δΈζζζ‘£ | π€ Contributing | π§ͺ Testing
πΊ Watch Full Demo Video (2:07, click to download)
Quick demonstration of AGI.Kapster's capture and annotation capabilities
- Global Hotkeys:
Alt+Ato capture,Alt+Sfor settings - Multi-Monitor: Seamless across all displays
- Element Detection: Auto UI element detection (Windows)
- Single Instance: Only one app instance runs at a time
- Tools: Arrow (A), Rectangle (R), Ellipse (E), Text (T), Freehand (F), Mosaic (M), Emoji (J)
- Customization: Colors, thickness, fonts, sizes
- Undo/Redo:
Ctrl+Z/Ctrl+Y - Hotkey Access: Press tool key while drawing
- Formats: PNG, JPEG, BMP, TIFF, WebP
- Quick Export:
Enter(clipboard) orCtrl+S(save) - Auto-Update: Configurable update checking
- System Startup: Optional auto-start with OS
| Platform | Version | Architecture | Runtime |
|---|---|---|---|
| Windows | Windows 10 1809+ | x64, ARM64 | .NET 10.0 Desktop |
| macOS | macOS 10.15+ | x64, ARM64 | .NET 10.0 Runtime |
| Linux | Ubuntu 20.04+ | x64, ARM64 | .NET 10.0 Runtime (X11/Wayland) |
Download from GitHub Releases:
Windows:
AGI.Kapster-win-x64.msi- Windows InstallerAGI.Kapster-win-x64-portable.zip- Portable version
macOS:
AGI.Kapster-osx-x64.pkg- Intel MacAGI.Kapster-osx-arm64.pkg- Apple Silicon
Unsigned packages may require removing the quarantine attribute:
xattr -d com.apple.quarantine <your>.pkg
Linux:
agi-kapster_*_amd64.deb- Debian/Ubuntuagi-kapster-*-1.x86_64.rpm- Red Hat/CentOS/FedoraAGI.Kapster-linux-x64-portable.zip- Portable version
git clone https://github.com/AGIBuild/AGI.Kapster.git
cd AGI.Kapster
./build.ps1 # Build and test
./build.ps1 Publish # Create packages- Start Application: Launch from Start Menu/Applications
- Grant Permissions: Allow screen recording (macOS)
- Take Screenshot: Use
Alt+Ahotkey or system tray icon - Annotate: Use toolbar tools to add annotations
- Export: Press
Enterto copy orCtrl+Sto save
| Action | Hotkey | Description |
|---|---|---|
| Capture Screen | Alt+A |
Start screen capture |
| Open Settings | Alt+S |
Open settings window |
| Save to File | Ctrl+S |
Save current capture |
| Copy to Clipboard | Enter |
Copy to clipboard |
| Cancel | Escape |
Cancel operation |
| Action | Hotkey | Description |
|---|---|---|
| Undo | Ctrl+Z |
Undo last action |
| Redo | Ctrl+Y or Ctrl+Shift+Z |
Redo last undone action |
| Select All | Ctrl+A |
Select all annotations |
| Delete Selection | Delete |
Remove selected items |
| Move Selection | Arrow keys | Nudge by 1 px |
| Adjust Stroke Width | Ctrl+- / Ctrl++ |
Decrease/Increase width |
| Tool | Hotkey | Description |
|---|---|---|
| Select | S |
Selection/edit mode |
| Arrow | A |
Draw arrows |
| Rectangle | R |
Draw rectangles |
| Ellipse | E |
Draw ellipses |
| Text | T |
Add text |
| Freehand | F |
Free drawing |
| Mosaic | M |
Pixelate/blur regions |
| Emoji | J |
Insert emoji |
| Color Picker | C |
Pick color |
- .NET 10.0 SDK
- Visual Studio 2022 / JetBrains Rider / VS Code
git clone https://github.com/AGIBuild/AGI.Kapster.git
cd AGI.Kapster
dotnet restore
./build.ps1
# Run application
dotnet run --project src/AGI.Kapster.Desktop# Run all tests
./build.ps1 Test
# Run with coverage
./build.ps1 Test -CoverageAGI.Kapster is a personal open-source project developed with passion and care. While we strive to provide the best experience across all platforms, please note:
- Primary Testing: Most testing is conducted on Windows and macOS platforms
- Linux Support: Linux functionality is implemented but may receive less extensive testing
- Known Limitations: Some platform-specific features or edge cases may not be fully covered
We appreciate your understanding that as a personal project, resources for comprehensive cross-platform testing are limited. Your experience and feedback help make AGI.Kapster better for everyone!
We warmly welcome contributions from the community:
- π Report Issues: Found a bug? Please open an issue on GitHub
- π‘ Share Feedback: Tell us about your experience on different platforms
- π§ Contribute Code: Pull requests are always welcome! See CONTRIBUTING.md
- π Improve Documentation: Help us make the docs better
- β Star the Project: Show your support by starring the repository
Your platform experience matters! Whether you're on Windows, macOS, or Linux, we'd love to hear from you. Every issue report and suggestion helps improve the tool for the entire community.
This project is developed with AI assistance. The primary purpose of AGI.Kapster is to explore the feasibility of using AI tools (such as GitHub Copilot, Cursor, Claude, etc.) for real-world software development and to document practical experiences and best practices in AI-assisted programming.
While this project is AI-assisted, I am committed to ensuring its sustainability and production-readiness. However, due to limited time and resources, it is not possible to thoroughly test all scenarios and edge cases. You may encounter various issues during use.
Please note:
- Linux platform has NOT been tested - functionality on Linux distributions is unverified
- Some features may behave unexpectedly on certain system configurations
- Bug reports and feedback are highly appreciated to help improve the project
By using this software, you acknowledge that it is provided "as is" without warranty of any kind. Use at your own risk.
This project is licensed under the MIT License.
AGI.Kapster - Making screenshot annotation simpler and more efficient! π