Keyboard Manager

// Remapping structure
public class KeyRemapping
{
    public uint OriginalKey { get; set; }     // Virtual key code
    public uint RemappedKey { get; set; }     // Target virtual key code
}

public class ShortcutRemapping
{
    public Shortcut Original { get; set; }
    public Shortcut Remapped { get; set; }
    public string TargetApp { get; set; }     // Optional, for app-specific
}

public class Shortcut
{
    public uint Key { get; set; }
    public bool Win { get; set; }
    public bool Ctrl { get; set; }
    public bool Alt { get; set; }
    public bool Shift { get; set; }
}

%LOCALAPPDATA%\Microsoft\PowerToys\KeyboardManager\default.json

// Install keyboard hook
HHOOK keyboardHook = SetWindowsHookEx(
    WH_KEYBOARD_LL,           // Low-level keyboard hook
    KeyboardProc,             // Callback function
    hInstance,
    0                         // All threads
);

// Hook callback
LRESULT CALLBACK KeyboardProc(
    int nCode,
    WPARAM wParam,
    LPARAM lParam)
{
    if (nCode == HC_ACTION)
    {
        KBDLLHOOKSTRUCT* kbd = (KBDLLHOOKSTRUCT*)lParam;
        
        // Check if key should be remapped
        if (ShouldRemapKey(kbd->vkCode))
        {
            uint remappedKey = GetRemappedKey(kbd->vkCode);
            
            // Inject remapped key
            InjectKey(remappedKey, wParam);
            
            // Block original key
            return 1;
        }
    }
    
    return CallNextHookEx(keyboardHook, nCode, wParam, lParam);
}

void InjectKey(UINT vkCode, WPARAM event)
{
    INPUT input = {};
    input.type = INPUT_KEYBOARD;
    input.ki.wVk = vkCode;
    input.ki.dwFlags = (event == WM_KEYUP) ? KEYEVENTF_KEYUP : 0;
    
    SendInput(1, &input, sizeof(INPUT));
}

// Common virtual key codes
#define VK_BACK         0x08  // Backspace
#define VK_TAB          0x09  // Tab
#define VK_RETURN       0x0D  // Enter
#define VK_SHIFT        0x10  // Shift
#define VK_CONTROL      0x11  // Ctrl
#define VK_MENU         0x12  // Alt
#define VK_CAPITAL      0x14  // Caps Lock
#define VK_ESCAPE       0x1B  // Escape
#define VK_SPACE        0x20  // Space
// ... and many more

Common productivity remappings:

✓ Caps Lock → Ctrl or Escape
  (Most users don't need Caps Lock)

✓ Right Alt → Win
  (Easier PowerToys shortcuts)

✓ Menu Key → Ctrl
  (Rarely used key becomes useful)

✗ Avoid remapping:
  - Left Ctrl (too many shortcuts depend on it)
  - Enter (critical for many operations)
  - Backspace (essential editing key)