feat: blocking permission hook with FIFO-based approval

install.sh

@@ -172,14 +172,19 @@ else:
     settings = {}
 
 hooks = settings.setdefault("hooks", {})
-for event, arg in [("Stop", "stop"), ("PermissionRequest", "permission")]:
+# Permission hook blocks on a FIFO until the user approves via stack-nudge,
+# so it needs a longer timeout than Claude Code's 600s default.
+for event, arg, timeout in [("Stop", "stop", 30), ("PermissionRequest", "permission", 600)]:
     groups = hooks.setdefault(event, [])
     cmd = f"{notify} claude-code {arg}"
     if not any(
         any(h.get("command") == cmd for h in g.get("hooks", []))
         for g in groups
     ):
-        groups.append({"matcher": "", "hooks": [{"type": "command", "command": cmd}]})
+        groups.append({
+            "matcher": "",
+            "hooks": [{"type": "command", "command": cmd, "timeout": timeout}],
+        })
 
 path.write_text(json.dumps(settings, indent=2) + "\n")
 print(f"  Updated {path}")

notify.sh

@@ -282,6 +282,7 @@ post_to_panel() {
   NUDGE_WINDOW="$4" \
   NUDGE_IPC_HOOK="${VSCODE_IPC_HOOK_CLI:-}" \
   NUDGE_HAS_ACTION="$5" \
+  NUDGE_FIFO="${6:-}" \
   NUDGE_SOCK="$PANEL_SOCK" \
   NUDGE_AGENT_PID="${AGENT_PID:-}" \
   NUDGE_SHELL_PID="${SHELL_PID:-}" \
@@ -308,6 +309,7 @@ optional = {
     "bundle_id":     env.get("NUDGE_BUNDLE"),
     "window_title":  env.get("NUDGE_WINDOW"),
     "ipc_hook":      env.get("NUDGE_IPC_HOOK"),
+    "fifo_path":     env.get("NUDGE_FIFO"),
     "agent_pid":     env.get("NUDGE_AGENT_PID"),
     "shell_pid":     env.get("NUDGE_SHELL_PID"),
     "terminal_pid":  env.get("NUDGE_TERMINAL_PID"),
@@ -410,12 +412,16 @@ notify_macos() {
   fi
 
   local has_action="false"
-  [[ "${EVENT}" == "permission" ]] && has_action="true"
+  local fifo_path=""
+  if [[ "${EVENT}" == "permission" ]]; then
+    has_action="true"
+    fifo_path=$(create_perm_fifo)
+  fi
 
   # Post to the persistent app — it handles both the panel history and the
   # UNUserNotification banner based on the user's config. Backgrounded so
   # Python startup (~50ms) doesn't block the agent hook.
-  post_to_panel "${title}" "${message}" "${bundle_id}" "${project_name:-}" "${has_action}" &
+  post_to_panel "${title}" "${message}" "${bundle_id}" "${project_name:-}" "${has_action}" "${fifo_path}" &
 
   # Sound fires independently via afplay — guaranteed even if macOS throttles
   # or the app isn't running yet. Voice replaces the chime when enabled.
@@ -424,6 +430,63 @@ notify_macos() {
   fi
 
   speak_notification "${voice_message}"
+
+  # For permission events, block reading from the FIFO. The user's Allow
+  # click in the panel/banner writes "allow" to it; we then output the
+  # PermissionRequest decision JSON to stdout so Claude Code skips its
+  # own UI prompt entirely. Timeout falls back to Claude Code's UI.
+  if [[ -n "$fifo_path" ]]; then
+    wait_for_permission_response "$fifo_path"
+  fi
+}
+
+# Create a unique FIFO at /tmp for the user's response. Echoes the path.
+# Returns empty if mkfifo fails.
+create_perm_fifo() {
+  local fifo
+  fifo="/tmp/stack-nudge-perm-$$-$(date +%s)-$RANDOM.fifo"
+  if mkfifo -m 0600 "$fifo" 2>/dev/null; then
+    echo "$fifo"
+  fi
+}
+
+# Block reading the user's decision from the FIFO with a timeout. Outputs
+# the PermissionRequest JSON to stdout when read; silent on timeout so
+# Claude Code falls back to its own UI prompt.
+# Uses Python because bash's `read -t` doesn't time out the FIFO open() call.
+wait_for_permission_response() {
+  local fifo="$1"
+  local timeout=550  # Claude Code's hook timeout defaults to 600s — leave buffer
+
+  trap 'rm -f "$fifo"' EXIT
+
+  local decision
+  decision=$(NUDGE_FIFO="$fifo" NUDGE_TIMEOUT="$timeout" python3 - <<'PY' 2>/dev/null
+import os, select, sys
+fifo = os.environ["NUDGE_FIFO"]
+timeout = float(os.environ["NUDGE_TIMEOUT"])
+try:
+    fd = os.open(fifo, os.O_RDONLY | os.O_NONBLOCK)
+except OSError:
+    sys.exit(0)
+try:
+    r, _, _ = select.select([fd], [], [], timeout)
+    if r:
+        data = os.read(fd, 1024).decode("utf-8", errors="replace").strip()
+        sys.stdout.write(data)
+finally:
+    os.close(fd)
+PY
+)
+
+  case "$decision" in
+    allow)
+      printf '{"hookSpecificOutput":{"hookEventName":"PermissionRequest","decision":{"behavior":"allow"}}}\n'
+      ;;
+    deny)
+      printf '{"hookSpecificOutput":{"hookEventName":"PermissionRequest","decision":{"behavior":"deny","message":"Denied via stack-nudge"}}}\n'
+      ;;
+  esac
 }
 
 

panel/EventListener.swift

@@ -123,6 +123,7 @@ private struct NudgeEventDTO: Decodable {
     let terminal_app: String?
     let term_program: String?
     let session_id: String?
+    let fifo_path: String?
 
     func toNudgeEvent() -> NudgeEvent {
         NudgeEvent(
@@ -141,7 +142,8 @@ private struct NudgeEventDTO: Decodable {
             terminalPID: terminal_pid,
             terminalApp: terminal_app,
             termProgram: term_program,
-            sessionID: session_id
+            sessionID: session_id,
+            fifoPath: fifo_path
         )
     }
 }

panel/EventStore.swift

@@ -33,14 +33,19 @@ struct NudgeEvent: Identifiable, Equatable {
     let terminalApp: String?
     let termProgram: String?
     let sessionID: String?
+    // FIFO that the source notify.sh hook is blocking on. Writing
+    // "allow" or "deny" to it lets stack-nudge return a PermissionRequest
+    // decision to Claude Code without touching the terminal UI.
+    let fifoPath: String?
 
     init(agent: String, kind: NudgeKind, title: String, message: String,
          projectPath: String? = nil, bundleID: String? = nil,
          windowTitle: String? = nil, ipcHook: String? = nil,
          hasActionButton: Bool = false, timestamp: Date = Date(),
          agentPID: Int? = nil, shellPID: Int? = nil,
          terminalPID: Int? = nil, terminalApp: String? = nil,
-         termProgram: String? = nil, sessionID: String? = nil) {
+         termProgram: String? = nil, sessionID: String? = nil,
+         fifoPath: String? = nil) {
         self.id = UUID()
         self.agent = agent
         self.kind = kind
@@ -58,6 +63,7 @@ struct NudgeEvent: Identifiable, Equatable {
         self.terminalApp = terminalApp
         self.termProgram = termProgram
         self.sessionID = sessionID
+        self.fifoPath = fifoPath
     }
 }
 

panel/Panel.swift

@@ -323,6 +323,22 @@ final class PanelController: NSObject, NSApplicationDelegate, PanelKeyDelegate,
         startConfigWatcher()
         setupNotificationCenter()
         store.onAppend = { [weak self] event in self?.postBannerIfNeeded(event) }
+        nav.loadFromConfig()  // populate panelPinned + other live values up-front
+
+        // Auto-hide when the panel loses key focus, if pin is off.
+        // Detect "click outside" without polling — NSWindow fires this when
+        // another window or app takes focus.
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(panelDidResignKey),
+            name: NSWindow.didResignKeyNotification,
+            object: panel
+        )
+    }
+
+    @objc private func panelDidResignKey(_ notification: Notification) {
+        guard !nav.panelPinned, panel.isVisible else { return }
+        hidePanel()
     }
 
     // MARK: - UNUserNotificationCenter
@@ -394,6 +410,17 @@ final class PanelController: NSObject, NSApplicationDelegate, PanelKeyDelegate,
 
         store.remove(id: event.id)
         let approve = response.actionIdentifier == "ALLOW"
+
+        // If we have a FIFO, the source hook is blocking on it — write the
+        // decision and let Claude Code skip its own UI prompt entirely.
+        // No keystroke injection or window targeting needed.
+        if approve, let fifo = event.fifoPath {
+            DispatchQueue.global(qos: .userInitiated).async {
+                Self.writeFIFO(fifo, "allow")
+            }
+            return
+        }
+
         guard let bundleID = event.bundleID else { return }
 
         // Hide the app first so the system restores focus to the previous
@@ -413,6 +440,16 @@ final class PanelController: NSObject, NSApplicationDelegate, PanelKeyDelegate,
         }
     }
 
+    // Write a decision string to the hook's FIFO. The source notify.sh
+    // is blocked on `select`, so this returns immediately after writing.
+    private static func writeFIFO(_ path: String, _ decision: String) {
+        let fd = Darwin.open(path, O_WRONLY | O_NONBLOCK)
+        guard fd >= 0 else { return }
+        defer { Darwin.close(fd) }
+        let line = decision + "\n"
+        _ = line.withCString { Darwin.write(fd, $0, strlen($0)) }
+    }
+
     // Show banners even when the app is frontmost (needed for accessory apps).
     func userNotificationCenter(_ center: UNUserNotificationCenter,
                                 willPresent notification: UNNotification,
@@ -653,8 +690,18 @@ final class PanelController: NSObject, NSApplicationDelegate, PanelKeyDelegate,
         store.remove(id: event.id)
         hidePanel()
 
-        guard let bundleID = event.bundleID else { return }
         let sendApproval = approve && event.hasActionButton
+
+        // FIFO path = the source hook is blocking on a permission decision.
+        // Write "allow" to it and we're done — Claude Code skips its UI prompt.
+        if sendApproval, let fifo = event.fifoPath {
+            DispatchQueue.global(qos: .userInitiated).async {
+                Self.writeFIFO(fifo, "allow")
+            }
+            return
+        }
+
+        guard let bundleID = event.bundleID else { return }
         DispatchQueue.global(qos: .userInitiated).async {
             AppActivator.activate(
                 bundleID: bundleID,

panel/PanelNav.swift

@@ -30,6 +30,7 @@ final class PanelNav: ObservableObject {
     @Published var hotkeyError:     String?
     @Published var bannerEnabled:   Bool = true
     @Published var voiceEnabled:    Bool = false
+    @Published var panelPinned:     Bool = true
     @Published var soundStop:       String = "Glass"
     @Published var soundPermission: String = "Ping"
     @Published var voice:           String = "af_heart"
@@ -68,28 +69,30 @@ final class PanelNav: ObservableObject {
         "I'd love your input on this.",
     ]
 
-    var rowCount: Int { 10 }
+    var rowCount: Int { 11 }
 
     // Row layout (kept in one place so the controller, view, and indexing
     // logic all agree on what each row index means):
     //   0  Hotkey                hotkey-record
     //   1  Banner notifications  toggle
     //   2  Voice notifications   toggle
-    //   3  Agent done sound      cycle
-    //   4  Permission sound      cycle
-    //   5  Voice                 cycle
-    //   6  Speed                 cycle
-    //   7  Check permissions…    action
-    //   8  Open config file…     action
-    //   9  Quit panel            action
+    //   3  Pin panel             toggle
+    //   4  Agent done sound      cycle
+    //   5  Permission sound      cycle
+    //   6  Voice                 cycle
+    //   7  Speed                 cycle
+    //   8  Check permissions…    action
+    //   9  Open config file…     action
+    //  10  Quit panel            action
 
     // MARK: - Disk I/O
 
     func loadFromConfig() {
         let config = ConfigFile.read()
         hotkeyDisplay   = config["STACKNUDGE_PANEL_HOTKEY"]    ?? "cmd+opt+n"
-        bannerEnabled   = ConfigFile.bool(config, "STACKNUDGE_BANNER", default: true)
-        voiceEnabled    = ConfigFile.bool(config, "STACKNUDGE_VOICE",  default: false)
+        bannerEnabled   = ConfigFile.bool(config, "STACKNUDGE_BANNER",    default: true)
+        voiceEnabled    = ConfigFile.bool(config, "STACKNUDGE_VOICE",     default: false)
+        panelPinned     = ConfigFile.bool(config, "STACKNUDGE_PANEL_PIN", default: true)
         soundStop       = config["STACKNUDGE_SOUND_STOP"]       ?? "Glass"
         soundPermission = config["STACKNUDGE_SOUND_PERMISSION"] ?? "Ping"
         voice           = config["STACKNUDGE_VOICE_NAME"]       ?? "af_heart"
@@ -143,9 +146,9 @@ final class PanelNav: ObservableObject {
     func activate() {
         switch selectedSettingIndex {
         case 0: startRecordingHotkey()
-        case 7: actions?.checkPermissions()
-        case 8: actions?.openConfig()
-        case 9: actions?.quit()
+        case 8: actions?.checkPermissions()
+        case 9: actions?.openConfig()
+        case 10: actions?.quit()
         default: applyCycle(forward: true)
         }
     }
@@ -165,15 +168,18 @@ final class PanelNav: ObservableObject {
             voiceEnabled.toggle()
             ConfigFile.write(key: "STACKNUDGE_VOICE", value: voiceEnabled ? "true" : "false")
         case 3:
-            soundStop = step(soundStop, in: Self.macSounds, forward: forward, key: "STACKNUDGE_SOUND_STOP", preview: true)
+            panelPinned.toggle()
+            ConfigFile.write(key: "STACKNUDGE_PANEL_PIN", value: panelPinned ? "true" : "false")
         case 4:
-            soundPermission = step(soundPermission, in: Self.macSounds, forward: forward, key: "STACKNUDGE_SOUND_PERMISSION", preview: true)
+            soundStop = step(soundStop, in: Self.macSounds, forward: forward, key: "STACKNUDGE_SOUND_STOP", preview: true)
         case 5:
+            soundPermission = step(soundPermission, in: Self.macSounds, forward: forward, key: "STACKNUDGE_SOUND_PERMISSION", preview: true)
+        case 6:
             guard !voicesLoading, !voicesAvailable.isEmpty else { return }
             voice = step(voice, in: voicesAvailable, forward: forward, key: "STACKNUDGE_VOICE_NAME", preview: false)
             let phrase = Self.voicePreviewPhrases.randomElement() ?? "Hello."
             Speaker.speak(phrase, voice: voice, speed: String(format: "%.2f", voiceSpeed))
-        case 6:
+        case 7:
             let next = forward ? voiceSpeed + Self.speedStep : voiceSpeed - Self.speedStep
             voiceSpeed = max(Self.speedMin, min(Self.speedMax, (next * 100).rounded() / 100))
             ConfigFile.write(key: "STACKNUDGE_VOICE_SPEED", value: String(format: "%.2f", voiceSpeed))

panel/Settings.swift

@@ -30,22 +30,23 @@ struct SettingsView: View {
                         section("Toggles") {
                             row(1, label: "Banner notifications", kind: .toggle, value: nav.bannerEnabled ? "On" : "Off")
                             row(2, label: "Voice notifications",  kind: .toggle, value: nav.voiceEnabled  ? "On" : "Off")
+                            row(3, label: "Pin panel",            kind: .toggle, value: nav.panelPinned   ? "On" : "Off")
                         }
 
                         section("Sounds") {
-                            row(3, label: "Agent done", kind: .cycle, value: nav.soundStop)
-                            row(4, label: "Permission", kind: .cycle, value: nav.soundPermission)
+                            row(4, label: "Agent done", kind: .cycle, value: nav.soundStop)
+                            row(5, label: "Permission", kind: .cycle, value: nav.soundPermission)
                         }
 
                         section("Voice") {
-                            row(5, label: "Voice",  kind: .cycle, value: voiceLabel)
-                            row(6, label: "Speed",  kind: .cycle, value: String(format: "%.2f×", nav.voiceSpeed))
+                            row(6, label: "Voice",  kind: .cycle, value: voiceLabel)
+                            row(7, label: "Speed",  kind: .cycle, value: String(format: "%.2f×", nav.voiceSpeed))
                         }
 
                         section("Actions") {
-                            row(7, label: "Check permissions…", kind: .action, value: "")
-                            row(8, label: "Open config file…",  kind: .action, value: "")
-                            row(9, label: "Quit panel",         kind: .action, value: "")
+                            row(8, label: "Check permissions…", kind: .action, value: "")
+                            row(9, label: "Open config file…",  kind: .action, value: "")
+                            row(10, label: "Quit panel",        kind: .action, value: "")
                         }
                     }
                     .padding(.horizontal, 14)