NFC Actions

A Windows 11 system tray application that monitors NFC card readers and performs automated actions when NFC tags are detected.

Features

• System Tray Application: Runs in the background with a system tray icon
• Multi-Reader Support: Automatically detects and monitors all connected PC/SC-compatible NFC readers
• Dynamic USB Detection: Automatically handles USB reader plug/unplug events
• Reader Selection: Enable/disable monitoring for specific readers
• NDEF Payload Extraction: Reads NDEF data from NFC tags
• Configurable Actions:
  • Copy NDEF payload to clipboard
  • Launch URLs in default browser
  • Type NDEF content as keyboard input
• Persistent Settings: Remembers reader preferences and action settings between sessions

Requirements

• Windows 11 (or Windows 10 with PC/SC service)
• .NET 7.0 Runtime or later
• PC/SC-compatible NFC reader

Building the Application

Using Visual Studio 2022

1. Open NfcActions.sln in Visual Studio 2022
2. Build the solution (Ctrl+Shift+B)
3. Run the application (F5)

Using .NET CLI

dotnet build NfcActions.sln
dotnet run --project NfcActions/NfcActions.csproj

Usage

Starting the Application

When you run NFC Actions, it will:

1. Start minimized to the system tray
2. Show a notification balloon indicating it's running
3. Automatically detect all connected NFC readers
4. Begin monitoring enabled readers for card events

Accessing the Main Window

• Double-click the tray icon, OR
• Right-click the tray icon and select "Open"

Configuring Readers

In the main window:

1. View all detected NFC readers in the "Active Readers" list
2. Check/uncheck readers to enable/disable monitoring
3. Settings are saved automatically

Configuring Actions

Select which actions to perform when an NFC tag is detected:

• Copy NDEF data to clipboard: Copies the NDEF payload text to the clipboard
• Launch URLs in default browser: If the NDEF payload is a URL, opens it in your default browser
• Type NDEF content as keyboard input: Simulates typing the NDEF payload (useful for form filling)

Note: Only the payload from the first NDEF record is used. Tags with multiple messages/records will use the first one.

Exiting the Application

• Right-click the tray icon and select "Exit"

Settings

Settings are stored in:

%APPDATA%\NfcActions\settings.json

The settings file includes:

• List of disabled readers
• Action preferences (clipboard, URLs, keyboard)

Project Structure

NfcActions/
├── Models/
│   ├── AppSettings.cs      # Application settings model
│   └── ReaderItem.cs        # Reader list item model
├── Services/
│   ├── ActionService.cs     # Handles clipboard, browser, and keyboard actions
│   ├── CardReaderService.cs # PC/SC reader monitoring and card detection
│   ├── NdefParser.cs        # NDEF message parsing
│   └── SettingsService.cs   # Settings persistence
├── ViewModels/
│   └── MainViewModel.cs     # Main window view model
├── App.xaml                 # Application resources and startup
├── App.xaml.cs              # Application lifecycle and tray icon
├── MainWindow.xaml          # Main window UI
└── MainWindow.xaml.cs       # Main window code-behind

Dependencies

• PCSC (v7.0.1): PC/SC wrapper for smart card communication
• PCSC.Iso7816 (v7.0.1): ISO 7816 APDU commands
• InputSimulatorCore (v1.0.5): Keyboard input simulation
• System.Management (v9.0.10): USB device detection (via WMI)

Technical Details

NDEF Parsing

The application reads NDEF (NFC Data Exchange Format) messages from NFC tags using standard ISO 7816 APDUs:

• Selects the NDEF Tag Application
• Reads the Capability Container
• Reads the NDEF file
• Parses the NDEF message structure to extract the payload

Reader Monitoring

The application polls PC/SC readers every 500ms to detect:

• New readers being connected
• Readers being disconnected
• Cards being inserted
• Cards being removed

Thread Safety

All PC/SC operations are thread-safe and properly synchronized to handle concurrent reader access.

Troubleshooting

No Readers Detected

• Ensure your NFC reader is properly connected
• Check that the Windows Smart Card service is running:

  services.msc → Smart Card
  

• Try unplugging and replugging the reader

Card Not Detected

• Ensure the reader is enabled in the main window
• Try holding the card on the reader for a longer duration
• Some readers require specific card positioning

Actions Not Working

• Clipboard: Ensure no other application has locked the clipboard
• Browser: Check that you have a default browser configured
• Keyboard: The keyboard simulation requires the target window to have focus

License

This project is provided as-is for educational and development purposes.

Contributing

Feel free to submit issues or pull requests for improvements or bug fixes.