diff --git a/apps/macos/Sources/OpenClaw/CLIInstallPrompter.swift b/apps/macos/Sources/OpenClaw/CLIInstallPrompter.swift
index 4957245138f4..c503d5a9efcc 100644
--- a/apps/macos/Sources/OpenClaw/CLIInstallPrompter.swift
+++ b/apps/macos/Sources/OpenClaw/CLIInstallPrompter.swift
@@ -60,14 +60,17 @@ final class CLIInstallPrompter {
         guard lastPrompt != version else { return }
         AppDefaults.standard.set(version, forKey: cliInstallPromptedVersionKey)
 
-        if let target = self.installTargetForCurrentBuild(confirmStable: true) {
+        if let target = await self.installTargetForCurrentBuild(confirmStable: true, presentingSheetOn: nil) {
             Task { _ = await self.installCLI(target: target) }
         }
 
         self.logger.debug("cli install prompt handled reason=\(reason, privacy: .public)")
     }
 
-    func installTargetForCurrentBuild(confirmStable: Bool = false) -> CLIInstaller.InstallTarget? {
+    func installTargetForCurrentBuild(
+        confirmStable: Bool = false,
+        presentingSheetOn window: NSWindow?) async -> CLIInstaller.InstallTarget?
+    {
         let appVersion = Self.appVersion()
         if let target = CLIInstaller.automaticInstallTarget(
             appVersion: appVersion,
@@ -80,7 +83,7 @@ final class CLIInstallPrompter {
             alert.addButton(withTitle: "Install CLI")
             alert.addButton(withTitle: "Not Now")
             alert.addButton(withTitle: "Open Settings")
-            switch alert.runModal() {
+            switch await self.present(alert, presentingSheetOn: window) {
             case .alertFirstButtonReturn:
                 return target
             case .alertThirdButtonReturn:
@@ -91,14 +94,18 @@ final class CLIInstallPrompter {
             }
         }
 
-        return self.chooseChannel(
+        return await self.chooseChannel(
             suggested: CLIInstaller.suggestedChannel(
                 appVersion: appVersion,
-                isDebug: CLIInstallBuild.isDebug))
+                isDebug: CLIInstallBuild.isDebug),
+            presentingSheetOn: window)
             .map(CLIInstaller.InstallTarget.channel)
     }
 
-    private func chooseChannel(suggested: CLIInstaller.Channel) -> CLIInstaller.Channel? {
+    private func chooseChannel(
+        suggested: CLIInstaller.Channel,
+        presentingSheetOn window: NSWindow?) async -> CLIInstaller.Channel?
+    {
         let channels = [suggested] + CLIInstaller.Channel.allCases.filter { $0 != suggested }
         let alert = NSAlert()
         alert.messageText = "Choose OpenClaw CLI channel"
@@ -111,12 +118,18 @@ final class CLIInstallPrompter {
             alert.addButton(withTitle: channel.label)
         }
         alert.addButton(withTitle: "Not Now")
-        let response = alert.runModal()
+        let response = await self.present(alert, presentingSheetOn: window)
         let index = response.rawValue - NSApplication.ModalResponse.alertFirstButtonReturn.rawValue
         guard channels.indices.contains(index) else { return nil }
         return channels[index]
     }
 
+    private func present(_ alert: NSAlert, presentingSheetOn window: NSWindow?) async -> NSApplication.ModalResponse {
+        // Attaching onboarding alerts preserves their AX visibility and window-relative z-order.
+        guard let window else { return alert.runModal() }
+        return await alert.beginSheetModal(for: window)
+    }
+
     private func installCLI(
         target: CLIInstaller.InstallTarget,
         showCompletionAlert: Bool = true,
diff --git a/apps/macos/Sources/OpenClaw/Onboarding.swift b/apps/macos/Sources/OpenClaw/Onboarding.swift
index 02c729ef3916..5bc7db526502 100644
--- a/apps/macos/Sources/OpenClaw/Onboarding.swift
+++ b/apps/macos/Sources/OpenClaw/Onboarding.swift
@@ -539,6 +539,10 @@ final class OnboardingController: NSObject, NSWindowDelegate {
     static let shared = OnboardingController()
     static let windowStyleMask: NSWindow.StyleMask = [.titled, .closable, .resizable, .fullSizeContentView]
     private var window: NSWindow?
+    var sheetPresentationWindow: NSWindow? {
+        self.window
+    }
+
     /// Human description of work in flight ("Installing the Gateway…").
     /// While set, closing the window asks for confirmation instead of quitting
     /// setup mid-operation.
@@ -638,6 +642,7 @@ final class OnboardingController: NSObject, NSWindowDelegate {
 struct OnboardingView: View {
     enum CLIInstallPhase {
         case idle
+        case choosingTarget
         case installing
         case startingService
     }
diff --git a/apps/macos/Sources/OpenClaw/OnboardingView+Monitoring.swift b/apps/macos/Sources/OpenClaw/OnboardingView+Monitoring.swift
index 2e99e80098c5..8b8e5c2fed31 100644
--- a/apps/macos/Sources/OpenClaw/OnboardingView+Monitoring.swift
+++ b/apps/macos/Sources/OpenClaw/OnboardingView+Monitoring.swift
@@ -146,9 +146,6 @@ extension OnboardingView {
     func startCLIInstall() {
         guard self.onboardingVisible, !installingCLI else { return }
         installingCLI = true
-        OnboardingController.shared.setWindowCloseEnabled(false)
-        // Cmd-W bypasses the disabled close button; the delegate asks first.
-        OnboardingController.shared.busyReason = "OpenClaw is installing the Gateway service."
         Task { @MainActor in await self.runCLIInstall() }
     }
 
@@ -159,17 +156,24 @@ extension OnboardingView {
     }
 
     func runCLIInstall() async {
-        self.cliInstallPhase = .installing
+        self.cliInstallPhase = .choosingTarget
         defer {
             self.installingCLI = false
             self.cliInstallPhase = .idle
             OnboardingController.shared.setWindowCloseEnabled(true)
             OnboardingController.shared.busyReason = nil
         }
-        guard let target = CLIInstallPrompter.shared.installTargetForCurrentBuild() else {
+        // Choosing a target is not installation: keep its spinner and close/busy guards inactive.
+        guard let target = await CLIInstallPrompter.shared.installTargetForCurrentBuild(
+            presentingSheetOn: OnboardingController.shared.sheetPresentationWindow)
+        else {
             cliStatus = "CLI installation cancelled."
             return
         }
+        self.cliInstallPhase = .installing
+        OnboardingController.shared.setWindowCloseEnabled(false)
+        // Cmd-W bypasses the disabled close button; the delegate asks first.
+        OnboardingController.shared.busyReason = "OpenClaw is installing the Gateway service."
         let installed = await CLIInstaller.install(target: target) { message in
             self.cliStatus = message
         }
diff --git a/apps/macos/Sources/OpenClaw/OnboardingView+Pages.swift b/apps/macos/Sources/OpenClaw/OnboardingView+Pages.swift
index 741c8e3a2ce9..cb59d4631a01 100644
--- a/apps/macos/Sources/OpenClaw/OnboardingView+Pages.swift
+++ b/apps/macos/Sources/OpenClaw/OnboardingView+Pages.swift
@@ -879,6 +879,7 @@ extension OnboardingView {
     private var installStepStateForInstall: InstallStepState {
         if self.cliInstalled { return .done }
         if self.installingCLI {
+            if self.cliInstallPhase == .choosingTarget { return .pending }
             return self.cliInstallPhase == .startingService ? .done : .running
         }
         if self.installFailed { return .failed }