diff --git a/CLAUDE.md b/CLAUDE.md
index 59028b5..592ea72 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -9,7 +9,7 @@ A native macOS app that shows video from a capture device (camera / capture card
 - Optional start in full screen. On by default, choice is remembered.
 - Localization: English and Polish (`Resources/{en,pl}.lproj`), following the system language.
 - Extras: per-device format (resolution/FPS), scaling modes (fit/fill/stretch), always on top, mute (⇧⌘M), Window menu (system tiling, full screen ⌃⌘F), automatic resume when a device is unplugged/replugged.
-- Autostart menu: launch the app when a chosen USB device is attached (`Sources/Autostart.swift`, per-user LaunchAgent with an IOKit match on USB vendor/product ID parsed from `AVCaptureDevice.modelID`). `uninstall.sh` must remove the agent.
+- Autostart menu: launch the app when a chosen USB device is attached (`Sources/Autostart.swift`, per-user LaunchAgent with an IOKit match on USB vendor/product ID parsed from `AVCaptureDevice.modelID`). `uninstall.sh` must remove the agent. The agent runs the app executable itself, and `main.swift` must keep acknowledging the `com.apple.iokit.matching` event stream — otherwise launchd relaunches the job every 10 s while the device is attached.
 - Out of scope (for now): launch at login, recording, screenshots, volume slider.
 
 ## Structure
diff --git a/Sources/App.swift b/Sources/App.swift
index c0b384a..792a3f4 100644
--- a/Sources/App.swift
+++ b/Sources/App.swift
@@ -16,6 +16,10 @@ final class App: NSObject, NSApplicationDelegate {
     let defaults = UserDefaults.standard
 
     func applicationDidFinishLaunching(_ n: Notification) {
+        // launched by the autostart agent while already running: just bring the running one forward
+        if let other = NSRunningApplication.runningApplications(withBundleIdentifier: Bundle.main.bundleIdentifier ?? "").first(where: { $0 != .current }) {
+            other.activate(); return NSApp.terminate(nil)
+        }
         guard !videoDevices().isEmpty else { return quitNoDevices() }
         window = NSWindow(contentRect: NSRect(x: 0, y: 0, width: 960, height: 540),
                           styleMask: [.titled, .closable, .miniaturizable, .resizable],
diff --git a/Sources/Autostart.swift b/Sources/Autostart.swift
index 434fca7..fe9bdba 100644
--- a/Sources/Autostart.swift
+++ b/Sources/Autostart.swift
@@ -37,7 +37,8 @@ extension App {
         }
         let plist: [String: Any] = [
             "Label": Self.agentLabel,
-            "ProgramArguments": ["/usr/bin/open", Bundle.main.bundlePath],
+            "ProgramArguments": [Bundle.main.executablePath ?? ""],  // the job itself must be the app so it can acknowledge the event
+            "LimitLoadToSessionType": "Aqua",
             "LaunchEvents": ["com.apple.iokit.matching": ["attach": [
                 "IOProviderClass": "IOUSBHostDevice", "idVendor": ids.vendor, "idProduct": ids.product, "IOMatchLaunchStream": true]]],
         ]
diff --git a/Sources/main.swift b/Sources/main.swift
index 144eae4..a2c05ac 100644
--- a/Sources/main.swift
+++ b/Sources/main.swift
@@ -1,4 +1,8 @@
 import AppKit
+import XPC
+
+// Acknowledge launchd's USB-match events (see Autostart.swift); unacknowledged ones make launchd relaunch the job every 10 s.
+xpc_set_event_stream_handler("com.apple.iokit.matching", nil) { _ in }
 
 let app = NSApplication.shared
 let delegate = App()