Add xdg-desktop-portal GlobalShortcuts backend for Wayland (Linux)

Implements a three-tier hotkey backend chain on Linux:
1. xdg-desktop-portal GlobalShortcuts — works on Hyprland, GNOME, and KDE
   without any privilege setup; requires one bind line in hyprland.conf for Hyprland
2. evdev — fallback for users in the input group or with systemd-logind seat ACLs
3. X11 XGrabKey — last resort for plain X11 sessions

Fixes double-fire on Hyprland by filtering signals by sig.Name to guard
against Deactivated events leaking through the Activated match rule.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

go.mod

@@ -9,7 +9,9 @@ require (
 )
 
 require (
+	fyne.io/systray v1.12.1 // indirect
+	github.com/godbus/dbus/v5 v5.1.0 // indirect
 	github.com/gorilla/websocket v1.4.2 // indirect
 	golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b // indirect
-	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 // indirect
+	golang.org/x/sys v0.15.0 // indirect
 )

go.sum

@@ -1,5 +1,9 @@
+fyne.io/systray v1.12.1 h1:ygBD6aZXwiOmZoY5N+ukbH9pih0Kq6fYgVeMYbr5skQ=
+fyne.io/systray v1.12.1/go.mod h1:RVwqP9nYMo7h5zViCBHri2FgjXF7H2cub7MAq4NSoLs=
 github.com/bwmarrin/discordgo v0.29.0 h1:FmWeXFaKUwrcL3Cx65c20bTRW+vOb6k8AnaP+EgjDno=
 github.com/bwmarrin/discordgo v0.29.0/go.mod h1:NJZpH+1AfhIcyQsPeuBKsUtYrRnjkyu0kIVMCHkZtRY=
+github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
+github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 golang.design/x/hotkey v0.4.1 h1:zLP/2Pztl4WjyxURdW84GoZ5LUrr6hr69CzJFJ5U1go=
@@ -12,6 +16,8 @@ golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/sys v0.0.0-20201022201747-fb209a7c41cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
+golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

hotkey_notwindows.go

@@ -0,0 +1,24 @@
+//go:build !windows && !linux
+
+package main
+
+import "golang.design/x/hotkey"
+
+func startHotkey(keybind string) (<-chan struct{}, error) {
+	mods, key, err := parseKeybind(keybind)
+	if err != nil {
+		return nil, err
+	}
+	hk := hotkey.New(mods, key)
+	if err := hk.Register(); err != nil {
+		return nil, err
+	}
+	out := make(chan struct{})
+	go func() {
+		for range hk.Keydown() {
+			out <- struct{}{}
+		}
+		close(out)
+	}()
+	return out, nil
+}

icon.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/png"
+)
+
+func monkeyIcon() []byte {
+	const size = 32
+	img := image.NewRGBA(image.Rect(0, 0, size, size))
+
+	brown := color.RGBA{110, 72, 38, 255}
+	tan   := color.RGBA{210, 175, 130, 255}
+	pink  := color.RGBA{190, 130, 110, 255}
+	dark  := color.RGBA{15, 8, 3, 255}
+	white := color.RGBA{255, 255, 255, 255}
+
+	// Ears drawn first so the head circle overlaps the inner edge naturally.
+	fillCircle(img, 4, 13, 5, brown)
+	fillCircle(img, 28, 13, 5, brown)
+	fillCircle(img, 4, 13, 3, pink)
+	fillCircle(img, 28, 13, 3, pink)
+
+	fillCircle(img, 16, 15, 13, brown) // head
+
+	fillEllipse(img, 16, 21, 7, 4, tan) // muzzle
+
+	// Eyes: light surround, dark iris, white highlight.
+	fillCircle(img, 11, 12, 3, tan)
+	fillCircle(img, 21, 12, 3, tan)
+	fillCircle(img, 11, 12, 2, dark)
+	fillCircle(img, 21, 12, 2, dark)
+	fillCircle(img, 12, 11, 1, white)
+	fillCircle(img, 22, 11, 1, white)
+
+	// Nostrils.
+	fillCircle(img, 14, 21, 1, dark)
+	fillCircle(img, 18, 21, 1, dark)
+
+	var buf bytes.Buffer
+	_ = png.Encode(&buf, img)
+	return buf.Bytes()
+}
+
+func fillCircle(img *image.RGBA, cx, cy, r int, c color.RGBA) {
+	for y := cy - r; y <= cy+r; y++ {
+		for x := cx - r; x <= cx+r; x++ {
+			dx, dy := x-cx, y-cy
+			if dx*dx+dy*dy <= r*r {
+				img.SetRGBA(x, y, c)
+			}
+		}
+	}
+}
+
+func fillEllipse(img *image.RGBA, cx, cy, rx, ry int, c color.RGBA) {
+	for y := cy - ry; y <= cy+ry; y++ {
+		for x := cx - rx; x <= cx+rx; x++ {
+			dx := float64(x-cx) / float64(rx)
+			dy := float64(y-cy) / float64(ry)
+			if dx*dx+dy*dy <= 1.0 {
+				img.SetRGBA(x, y, c)
+			}
+		}
+	}
+}

keybind_linux.go

@@ -2,9 +2,24 @@
 
 package main
 
-import "golang.design/x/hotkey"
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
 
-// Mod1 = Alt, Mod4 = Super/Win on most Linux desktop environments.
+	dbus "github.com/godbus/dbus/v5"
+	"golang.design/x/hotkey"
+)
+
+// modMap is used by parseKeybind (called from main.go and tests).
 var modMap = map[string]hotkey.Modifier{
 	"ctrl":  hotkey.ModCtrl,
 	"shift": hotkey.ModShift,
@@ -12,3 +27,328 @@ var modMap = map[string]hotkey.Modifier{
 	"win":   hotkey.Mod4,
 	"super": hotkey.Mod4,
 }
+
+// ── Portal (xdg-desktop-portal GlobalShortcuts) ──────────────────────────────
+
+// toPortalTrigger converts "ctrl+alt+m" → "<Control><Alt>m".
+func toPortalTrigger(keybind string) string {
+	parts := strings.Split(strings.ToLower(strings.TrimSpace(keybind)), "+")
+	mods := map[string]string{
+		"ctrl": "<Control>", "shift": "<Shift>",
+		"alt": "<Alt>", "win": "<Super>", "super": "<Super>",
+	}
+	var sb strings.Builder
+	for _, p := range parts[:len(parts)-1] {
+		if m, ok := mods[strings.TrimSpace(p)]; ok {
+			sb.WriteString(m)
+		}
+	}
+	sb.WriteString(strings.TrimSpace(parts[len(parts)-1]))
+	return sb.String()
+}
+
+func startHotkeyPortal(keybind string) (<-chan struct{}, error) {
+	if os.Getenv("WAYLAND_DISPLAY") == "" {
+		return nil, fmt.Errorf("not a Wayland session")
+	}
+
+	conn, err := dbus.SessionBus()
+	if err != nil {
+		return nil, fmt.Errorf("D-Bus session bus: %w", err)
+	}
+
+	// ":1.123" → "1_123"
+	sender := strings.ReplaceAll(strings.TrimPrefix(conn.Names()[0], ":"), ".", "_")
+	portal := conn.Object("org.freedesktop.portal.Desktop", "/org/freedesktop/portal/desktop")
+	pid := os.Getpid()
+
+	awaitResponse := func(token string) (map[string]dbus.Variant, error) {
+		reqPath := dbus.ObjectPath(fmt.Sprintf(
+			"/org/freedesktop/portal/desktop/request/%s/%s", sender, token))
+		ch := make(chan *dbus.Signal, 8)
+		conn.Signal(ch)
+		defer conn.RemoveSignal(ch)
+		opts := []dbus.MatchOption{
+			dbus.WithMatchInterface("org.freedesktop.portal.Request"),
+			dbus.WithMatchMember("Response"),
+			dbus.WithMatchObjectPath(reqPath),
+		}
+		if err := conn.AddMatchSignal(opts...); err != nil {
+			return nil, err
+		}
+		defer conn.RemoveMatchSignal(opts...) //nolint:errcheck
+		for {
+			select {
+			case sig := <-ch:
+				if sig == nil || sig.Path != reqPath {
+					continue
+				}
+				if code, _ := sig.Body[0].(uint32); code != 0 {
+					return nil, fmt.Errorf("portal declined (code %d)", code)
+				}
+				if results, ok := sig.Body[1].(map[string]dbus.Variant); ok {
+					return results, nil
+				}
+				return map[string]dbus.Variant{}, nil
+			case <-time.After(30 * time.Second):
+				return nil, fmt.Errorf("portal response timed out")
+			}
+		}
+	}
+
+	// CreateSession
+	reqToken1 := fmt.Sprintf("dlm_r1_%d", pid)
+	sessToken := fmt.Sprintf("dlm_s_%d", pid)
+	if err := portal.Call("org.freedesktop.portal.GlobalShortcuts.CreateSession", 0,
+		map[string]dbus.Variant{
+			"handle_token":         dbus.MakeVariant(reqToken1),
+			"session_handle_token": dbus.MakeVariant(sessToken),
+		}).Err; err != nil {
+		return nil, fmt.Errorf("GlobalShortcuts portal unavailable: %w", err)
+	}
+	if _, err := awaitResponse(reqToken1); err != nil {
+		return nil, fmt.Errorf("CreateSession: %w", err)
+	}
+	// xdg-desktop-portal-hyprland doesn't populate session_handle in the response
+	// (spec bug). The path is always predictable from sender + session token.
+	sessionHandle := dbus.ObjectPath(fmt.Sprintf(
+		"/org/freedesktop/portal/desktop/session/%s/%s", sender, sessToken))
+
+	// BindShortcuts — portal expects a(sa{sv}): array of (id, props) structs.
+	type shortcutEntry struct {
+		ID    string
+		Props map[string]dbus.Variant
+	}
+	reqToken2 := fmt.Sprintf("dlm_r2_%d", pid)
+	shortcuts := []shortcutEntry{{
+		ID: "mute-toggle",
+		Props: map[string]dbus.Variant{
+			"description":       dbus.MakeVariant("Toggle Discord Lobby Mute"),
+			"preferred_trigger": dbus.MakeVariant(toPortalTrigger(keybind)),
+		},
+	}}
+	if err := portal.Call("org.freedesktop.portal.GlobalShortcuts.BindShortcuts", 0,
+		sessionHandle, shortcuts, "", map[string]dbus.Variant{
+			"handle_token": dbus.MakeVariant(reqToken2),
+		}).Err; err != nil {
+		return nil, fmt.Errorf("BindShortcuts: %w", err)
+	}
+	if _, err := awaitResponse(reqToken2); err != nil {
+		return nil, fmt.Errorf("BindShortcuts: %w", err)
+	}
+
+	// Activated signals are emitted from /org/freedesktop/portal/desktop,
+	// not from the session handle path.
+	const portalDesktopPath = dbus.ObjectPath("/org/freedesktop/portal/desktop")
+	out := make(chan struct{}, 1)
+	sigCh := make(chan *dbus.Signal, 8)
+	conn.Signal(sigCh)
+	conn.AddMatchSignal( //nolint:errcheck
+		dbus.WithMatchInterface("org.freedesktop.portal.GlobalShortcuts"),
+		dbus.WithMatchMember("Activated"),
+		dbus.WithMatchObjectPath(portalDesktopPath),
+	)
+	go func() {
+		for sig := range sigCh {
+			if sig.Name != "org.freedesktop.portal.GlobalShortcuts.Activated" {
+				continue
+			}
+			if sig.Path != portalDesktopPath || len(sig.Body) < 2 {
+				continue
+			}
+			// Body: (o session_handle, s shortcut_id, t timestamp, a{sv} options)
+			if sh, _ := sig.Body[0].(dbus.ObjectPath); sh != sessionHandle {
+				continue
+			}
+			if id, _ := sig.Body[1].(string); id == "mute-toggle" {
+				select {
+				case out <- struct{}{}:
+				default:
+				}
+			}
+		}
+	}()
+
+	return out, nil
+}
+
+// ── evdev ─────────────────────────────────────────────────────────────────────
+
+// evdev key codes from linux/input-event-codes.h
+var evdevKeyMap = map[string]uint16{
+	"a": 30, "b": 48, "c": 46, "d": 32, "e": 18, "f": 33, "g": 34, "h": 35,
+	"i": 23, "j": 36, "k": 37, "l": 38, "m": 50, "n": 49, "o": 24, "p": 25,
+	"q": 16, "r": 19, "s": 31, "t": 20, "u": 22, "v": 47, "w": 17, "x": 45,
+	"y": 21, "z": 44,
+	"0": 11, "1": 2, "2": 3, "3": 4, "4": 5, "5": 6, "6": 7, "7": 8, "8": 9, "9": 10,
+	"f1": 59, "f2": 60, "f3": 61, "f4": 62, "f5": 63, "f6": 64, "f7": 65, "f8": 66,
+	"f9": 67, "f10": 68, "f11": 87, "f12": 88,
+	"f13": 183, "f14": 184, "f15": 185, "f16": 186,
+	"f17": 187, "f18": 188, "f19": 189, "f20": 190,
+	"space": 57, "return": 28, "enter": 28, "escape": 1, "esc": 1,
+	"tab": 15, "delete": 111, "left": 105, "right": 106, "up": 103, "down": 108,
+}
+
+// evdevModGroups maps each modifier to its [leftKey, rightKey] evdev codes.
+var evdevModGroups = map[string][]uint16{
+	"ctrl":  {29, 97},
+	"shift": {42, 54},
+	"alt":   {56, 100},
+	"win":   {125, 126},
+	"super": {125, 126},
+}
+
+func parseEvdevKeybind(s string) (modGroups [][]uint16, mainKey uint16, err error) {
+	parts := strings.Split(strings.ToLower(strings.TrimSpace(s)), "+")
+	if len(parts) == 0 {
+		return nil, 0, fmt.Errorf("empty keybind")
+	}
+	for _, p := range parts[:len(parts)-1] {
+		p = strings.TrimSpace(p)
+		g, ok := evdevModGroups[p]
+		if !ok {
+			return nil, 0, fmt.Errorf("unknown modifier %q", p)
+		}
+		modGroups = append(modGroups, g)
+	}
+	keyStr := strings.TrimSpace(parts[len(parts)-1])
+	k, ok := evdevKeyMap[keyStr]
+	if !ok {
+		return nil, 0, fmt.Errorf("unknown key %q", keyStr)
+	}
+	return modGroups, k, nil
+}
+
+// eviocgbitKey = EVIOCGBIT(EV_KEY=1, 32): 256-bit mask of supported key codes.
+// _IOC(_IOC_READ=2, 'E', 0x21, 32) on Linux x86-64.
+const eviocgbitKey = uintptr(0x80204521)
+
+func hasKey(f *os.File, code uint16) bool {
+	if code >= 256 {
+		return false
+	}
+	var bits [32]byte
+	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), eviocgbitKey, uintptr(unsafe.Pointer(&bits[0])))
+	return errno == 0 && bits[code/8]&(1<<(code%8)) != 0
+}
+
+func comboActive(held map[uint16]bool, modGroups [][]uint16, mainKey uint16) bool {
+	if !held[mainKey] {
+		return false
+	}
+	for _, group := range modGroups {
+		found := false
+		for _, code := range group {
+			if held[code] {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+func startHotkeyEvdev(keybind string) (<-chan struct{}, error) {
+	modGroups, mainKey, err := parseEvdevKeybind(keybind)
+	if err != nil {
+		return nil, err
+	}
+	paths, _ := filepath.Glob("/dev/input/event*")
+	var devices []*os.File
+	for _, p := range paths {
+		f, err := os.Open(p)
+		if err != nil {
+			continue
+		}
+		if hasKey(f, mainKey) {
+			devices = append(devices, f)
+		} else {
+			f.Close()
+		}
+	}
+	if len(devices) == 0 {
+		return nil, fmt.Errorf("no accessible keyboard devices in /dev/input (add user to 'input' group)")
+	}
+	ch := make(chan struct{}, 1)
+	var mu sync.Mutex
+	held := make(map[uint16]bool)
+	for _, dev := range devices {
+		go func(f *os.File) {
+			defer f.Close()
+			// input_event on 64-bit Linux: 8+8 bytes timeval + 2+2+4 = 24 bytes
+			buf := make([]byte, 24)
+			for {
+				if _, err := io.ReadFull(f, buf); err != nil {
+					return
+				}
+				if binary.LittleEndian.Uint16(buf[16:18]) != 1 { // EV_KEY
+					continue
+				}
+				code := binary.LittleEndian.Uint16(buf[18:20])
+				value := int32(binary.LittleEndian.Uint32(buf[20:24]))
+				mu.Lock()
+				switch value {
+				case 1:
+					held[code] = true
+					if comboActive(held, modGroups, mainKey) {
+						select {
+						case ch <- struct{}{}:
+						default:
+						}
+					}
+				case 0:
+					delete(held, code)
+				}
+				mu.Unlock()
+			}
+		}(dev)
+	}
+	return ch, nil
+}
+
+// ── startHotkey: portal → evdev → X11 ────────────────────────────────────────
+
+func startHotkey(keybind string) (<-chan struct{}, error) {
+	// On Wayland, try xdg-desktop-portal GlobalShortcuts first.
+	// Works on GNOME, KDE, and Hyprland (via xdg-desktop-portal-hyprland)
+	// without any privilege setup.
+	if os.Getenv("WAYLAND_DISPLAY") != "" {
+		ch, err := startHotkeyPortal(keybind)
+		if err == nil {
+			log.Println("hotkey backend: xdg-desktop-portal")
+			return ch, nil
+		}
+		log.Printf("portal unavailable (%v), trying evdev", err)
+	}
+
+	// evdev: works on both X11 and Wayland if the user is in the 'input'
+	// group or systemd-logind grants seat ACLs (default on GNOME/KDE).
+	ch, err := startHotkeyEvdev(keybind)
+	if err == nil {
+		log.Println("hotkey backend: evdev")
+		return ch, nil
+	}
+	log.Printf("evdev unavailable (%v), falling back to X11", err)
+
+	// X11 XGrabKey: works on plain X11 sessions.
+	mods, key, err2 := parseKeybind(keybind)
+	if err2 != nil {
+		return nil, err2
+	}
+	hk := hotkey.New(mods, key)
+	if err2 := hk.Register(); err2 != nil {
+		return nil, fmt.Errorf("all hotkey backends failed — on Wayland without xdg-desktop-portal support, add user to 'input' group: %v", err2)
+	}
+	log.Println("hotkey backend: X11")
+	out := make(chan struct{})
+	go func() {
+		for range hk.Keydown() {
+			out <- struct{}{}
+		}
+		close(out)
+	}()
+	return out, nil
+}

keybind_windows.go

@@ -2,7 +2,14 @@
 
 package main
 
-import "golang.design/x/hotkey"
+import (
+	"fmt"
+	"runtime"
+	"syscall"
+	"unsafe"
+
+	"golang.design/x/hotkey"
+)
 
 var modMap = map[string]hotkey.Modifier{
 	"ctrl":  hotkey.ModCtrl,
@@ -11,3 +18,71 @@ var modMap = map[string]hotkey.Modifier{
 	"win":   hotkey.ModWin,
 	"super": hotkey.ModWin,
 }
+
+var (
+	user32             = syscall.NewLazyDLL("user32.dll")
+	procRegisterHotKey = user32.NewProc("RegisterHotKey")
+	procGetMessageW    = user32.NewProc("GetMessageW")
+)
+
+// winMsg mirrors the Win32 MSG struct.
+type winMsg struct {
+	hwnd    uintptr
+	message uint32
+	wParam  uintptr
+	lParam  uintptr
+	time    uint32
+	ptX     int32
+	ptY     int32
+}
+
+func startHotkey(keybind string) (<-chan struct{}, error) {
+	mods, key, err := parseKeybind(keybind)
+	if err != nil {
+		return nil, err
+	}
+
+	// hotkey.Modifier and hotkey.Key values on Windows are the native Win32
+	// MOD_* and VK_* constants, so they can be passed directly to RegisterHotKey.
+	var modFlags uintptr
+	for _, m := range mods {
+		modFlags |= uintptr(m)
+	}
+	vk := uintptr(key)
+
+	ch := make(chan struct{}, 1)
+	ready := make(chan error, 1)
+
+	go func() {
+		runtime.LockOSThread()
+		// Intentionally no defer UnlockOSThread — this goroutine owns its OS
+		// thread for the lifetime of the app to keep the hotkey message queue alive.
+
+		ret, _, e := procRegisterHotKey.Call(0, 1, modFlags, vk)
+		if ret == 0 {
+			ready <- fmt.Errorf("RegisterHotKey: %w", e)
+			return
+		}
+		close(ready)
+
+		const wmHotkey = 0x0312
+		var msg winMsg
+		for {
+			r, _, _ := procGetMessageW.Call(
+				uintptr(unsafe.Pointer(&msg)), 0, wmHotkey, wmHotkey,
+			)
+			if r == 0 || r == ^uintptr(0) { // WM_QUIT or error
+				return
+			}
+			select {
+			case ch <- struct{}{}:
+			default:
+			}
+		}
+	}()
+
+	if err := <-ready; err != nil {
+		return nil, err
+	}
+	return ch, nil
+}

main.go

@@ -3,14 +3,16 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
+	"fyne.io/systray"
 	"github.com/bwmarrin/discordgo"
 	"golang.design/x/hotkey"
-	"golang.design/x/mainthread"
 )
 
 type Config struct {
@@ -107,25 +109,46 @@ func toggleMute(dg *discordgo.Session, cfg *Config, muted bool) {
 	for _, vs := range guild.VoiceStates {
 		if vs.ChannelID == cfg.ChannelID && !exempt[vs.UserID] {
 			if err := dg.GuildMemberMute(cfg.GuildID, vs.UserID, muted); err != nil {
-				log.Printf("  warning: user %s: %v", vs.UserID, err)
+				log.Printf("warning: user %s: %v", vs.UserID, err)
 			}
 			count++
 		}
 	}
 	if count == 0 {
-		fmt.Println("  (no users found in channel)")
+		log.Println("(no users found in channel)")
 	} else {
-		fmt.Printf("  %d user(s) affected\n", count)
+		log.Printf("%d user(s) affected", count)
 	}
 }
 
-func main() { mainthread.Init(run) }
+func setupLogging() {
+	// Try exe directory first, fall back to temp dir (e.g. if installed in Program Files).
+	var dirs []string
+	if exe, err := os.Executable(); err == nil {
+		dirs = append(dirs, filepath.Dir(exe))
+	}
+	dirs = append(dirs, os.TempDir())
+
+	for _, dir := range dirs {
+		logPath := filepath.Join(dir, "discord-lobby-mute.log")
+		f, err := os.OpenFile(logPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+		if err != nil {
+			continue
+		}
+		log.SetOutput(io.MultiWriter(os.Stderr, f))
+		return
+	}
+}
 
 func run() {
+	setupLogging()
+	log.Println("starting")
+
 	cfg, err := loadConfig()
 	if err != nil {
 		log.Fatal(err)
 	}
+	log.Println("config loaded")
 
 	dg, err := discordgo.New("Bot " + cfg.Token)
 	if err != nil {
@@ -138,35 +161,49 @@ func run() {
 		close(ready)
 	})
 
+	log.Println("connecting to Discord...")
 	if err := dg.Open(); err != nil {
 		log.Fatalf("connect to Discord: %v", err)
 	}
 	defer dg.Close()
 
-	<-ready
+	select {
-	fmt.Println("Connected to Discord.")
+	case <-ready:
-
+	case <-time.After(30 * time.Second):
-	mods, key, err := parseKeybind(cfg.Keybind)
+		log.Fatal("timed out waiting for Discord ready — check token and network connection")
-	if err != nil {
-		log.Fatalf("keybind: %v", err)
 	}
+	log.Println("connected to Discord")
 
-	hk := hotkey.New(mods, key)
+	keydownCh, err := startHotkey(cfg.Keybind)
-	if err := hk.Register(); err != nil {
+	if err != nil {
 		log.Fatalf("register hotkey %q: %v", cfg.Keybind, err)
 	}
-	defer hk.Unregister()
 
-	fmt.Printf("Listening on %s — toggles server mute for channel %s\n", cfg.Keybind, cfg.ChannelID)
+	log.Printf("Listening on %s — toggles server mute for channel %s", cfg.Keybind, cfg.ChannelID)
 
-	muted := false
+	go func() {
-	for range hk.Keydown() {
+		muted := false
-		muted = !muted
+		for range keydownCh {
-		if muted {
+			muted = !muted
-			fmt.Print("Muting all users... ")
+			if muted {
-		} else {
+				log.Print("Muting all users...")
-			fmt.Print("Unmuting all users... ")
+			} else {
+				log.Print("Unmuting all users...")
+			}
+			toggleMute(dg, cfg, muted)
 		}
-		toggleMute(dg, cfg, muted)
+	}()
-	}
+
+	systray.Run(
+		func() {
+			systray.SetIcon(monkeyIcon())
+			systray.SetTooltip("Discord Lobby Mute — " + cfg.Keybind)
+			mQuit := systray.AddMenuItem("Quit", "Quit Discord Lobby Mute")
+			go func() {
+				<-mQuit.ClickedCh
+				systray.Quit()
+			}()
+		},
+		func() {},
+	)
 }

main_other.go

@@ -0,0 +1,7 @@
+//go:build !windows
+
+package main
+
+import "golang.design/x/mainthread"
+
+func main() { mainthread.Init(run) }

main_windows.go

@@ -0,0 +1,5 @@
+//go:build windows
+
+package main
+
+func main() { run() }