diff --git a/macos/fight-runner/.gitignore b/macos/fight-runner/.gitignore
new file mode 100644
index 0000000000..30bcfa4ed5
--- /dev/null
+++ b/macos/fight-runner/.gitignore
@@ -0,0 +1 @@
+.build/
diff --git a/macos/fight-runner/Package.swift b/macos/fight-runner/Package.swift
new file mode 100644
index 0000000000..171db262ef
--- /dev/null
+++ b/macos/fight-runner/Package.swift
@@ -0,0 +1,17 @@
+// swift-tools-version: 5.9
+import PackageDescription
+
+let package = Package(
+    name: "ACFightRunner",
+    platforms: [.macOS(.v12)],
+    targets: [
+        .executableTarget(
+            name: "ac-fight-runner",
+            linkerSettings: [
+                .linkedFramework("AppKit"),
+                .linkedFramework("WebKit"),
+                .linkedFramework("GameController"),
+            ]
+        )
+    ]
+)
diff --git a/macos/fight-runner/README.md b/macos/fight-runner/README.md
new file mode 100644
index 0000000000..6223ae3ede
--- /dev/null
+++ b/macos/fight-runner/README.md
@@ -0,0 +1,55 @@
+# AC Fight Runner for macOS
+
+A deliberately small native macOS host for running the live `fight.mjs` piece
+through `WKWebView`. It is a comparison BIOS for the Xbox dynamic shell: both
+load the deployed web runtime, while their native controller and WebView paths
+remain independently measurable.
+
+## Run
+
+```sh
+cd macos/fight-runner
+swift run ac-fight-runner
+```
+
+Use a local AC server or another endpoint without rebuilding:
+
+```sh
+swift run ac-fight-runner --url http://localhost:8888/fight
+AC_FIGHT_URL=https://staging.example/fight swift run ac-fight-runner
+```
+
+`Cmd-R` reloads from origin. For automatic reload, point the runner at a tiny
+endpoint whose response body or `ETag` changes when a deployment is ready:
+
+```sh
+swift run ac-fight-runner \
+  --url http://localhost:8888/fight \
+  --reload-endpoint http://localhost:8888/api/build-id
+```
+
+The host polls native `GameController` state at 60 Hz, logs controller identity
+and connection changes, displays identities at bottom-right, and publishes
+snapshots to the piece as both `window.acNativeGamepads` and the
+`ac-native-gamepads` DOM event. This is additive: WebKit's standard Gamepad API
+continues to work when available.
+
+## Where this fits
+
+- `ac-electron/` is the mature macOS/Windows desktop BIOS. Its flip view already
+  bridges Chromium host gamepads into a guest webview and has CDP automation.
+- `slab/menuband/Sources/MenuBand/AestheticWebWindow.swift` is the closest
+  existing native macOS BIOS: it already embeds AC in WKWebView and injects a
+  native bridge. Its `GamepadManager.swift` establishes GameController identity,
+  background monitoring, main-queue handlers, and positional face-button
+  semantics. This runner follows those contracts without importing the whole
+  piano/menubar executable.
+- `slab/menubar-swift/` supplies the broader native AppKit host conventions, but
+  is host tooling rather than an AC piece container.
+- `macos/fight-runner/` is intentionally focused: one native window, one live
+  piece, native controller telemetry, and no packaging or account machinery.
+- `xbox/` is the distribution target. Compare controller-to-piece timestamps and
+  audio/visual response between its WebView2 shell and this WKWebView shell.
+
+Executable updates still require rebuilding this host. Piece/runtime updates do
+not: change the URL content or reload endpoint and the same binary loads them.
diff --git a/macos/fight-runner/Sources/ac-fight-runner/main.swift b/macos/fight-runner/Sources/ac-fight-runner/main.swift
new file mode 100644
index 0000000000..73c033fe65
--- /dev/null
+++ b/macos/fight-runner/Sources/ac-fight-runner/main.swift
@@ -0,0 +1,194 @@
+import AppKit
+import GameController
+import WebKit
+
+private struct Options {
+    var baseURL = ProcessInfo.processInfo.environment["AC_FIGHT_URL"] ?? "https://aesthetic.computer/fight"
+    var watchURL = ProcessInfo.processInfo.environment["AC_FIGHT_RELOAD_ENDPOINT"]
+
+    init(arguments: [String]) {
+        var index = 1
+        while index < arguments.count {
+            switch arguments[index] {
+            case "--url" where index + 1 < arguments.count:
+                index += 1; baseURL = arguments[index]
+            case "--reload-endpoint" where index + 1 < arguments.count:
+                index += 1; watchURL = arguments[index]
+            case "--help", "-h":
+                print("usage: ac-fight-runner [--url URL] [--reload-endpoint URL]")
+                exit(0)
+            default: break
+            }
+            index += 1
+        }
+    }
+}
+
+private final class Runner: NSObject, NSApplicationDelegate, WKNavigationDelegate, WKScriptMessageHandler {
+    private let options = Options(arguments: CommandLine.arguments)
+    private var window: NSWindow!
+    private var webView: WKWebView!
+    private var controllerTimer: Timer?
+    private var reloadTimer: Timer?
+    private var reloadTag: String?
+
+    func applicationDidFinishLaunching(_ notification: Notification) {
+        let scripts = WKUserContentController()
+        scripts.add(self, name: "acNative")
+        scripts.addUserScript(WKUserScript(source: Self.hostScript, injectionTime: .atDocumentStart, forMainFrameOnly: true))
+        let configuration = WKWebViewConfiguration()
+        configuration.userContentController = scripts
+        configuration.websiteDataStore = .default()
+
+        webView = WKWebView(frame: .zero, configuration: configuration)
+        webView.customUserAgent = "AestheticComputerFightRunner/1 (Macintosh; native-host)"
+        webView.navigationDelegate = self
+        window = NSWindow(
+            contentRect: NSScreen.main?.visibleFrame ?? NSRect(x: 0, y: 0, width: 1280, height: 720),
+            styleMask: [.titled, .closable, .resizable, .miniaturizable],
+            backing: .buffered,
+            defer: false
+        )
+        window.title = "Aesthetic Computer — Fight (native macOS host)"
+        window.contentView = webView
+        window.makeKeyAndOrderFront(nil)
+        window.toggleFullScreen(nil)
+
+        installMenu()
+        observeControllers()
+        load()
+        if options.watchURL != nil { startReloadWatch() }
+    }
+
+    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool { true }
+
+    private func load() {
+        guard let url = URL(string: options.baseURL) else {
+            fputs("invalid --url: \(options.baseURL)\n", stderr); return
+        }
+        print("[fight-runner] loading \(url.absoluteString)")
+        webView.load(URLRequest(url: url, cachePolicy: .reloadRevalidatingCacheData))
+    }
+
+    private func reload() {
+        print("[fight-runner] reload")
+        webView.reloadFromOrigin()
+    }
+
+    private func installMenu() {
+        let menu = NSMenu()
+        let appItem = NSMenuItem(); menu.addItem(appItem)
+        let appMenu = NSMenu(); appItem.submenu = appMenu
+        appMenu.addItem(withTitle: "Reload Fight", action: #selector(reloadAction), keyEquivalent: "r").target = self
+        appMenu.addItem(withTitle: "Toggle Full Screen", action: #selector(NSWindow.toggleFullScreen(_:)), keyEquivalent: "f").target = window
+        appMenu.addItem(.separator())
+        appMenu.addItem(withTitle: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
+        NSApp.mainMenu = menu
+    }
+
+    @objc private func reloadAction() { reload() }
+
+    private func observeControllers() {
+        if #available(macOS 11.3, *) { GCController.shouldMonitorBackgroundEvents = true }
+        NotificationCenter.default.addObserver(forName: .GCControllerDidConnect, object: nil, queue: .main) { [weak self] note in
+            guard let pad = note.object as? GCController else { return }
+            print("[fight-runner] controller connected: \(pad.vendorName ?? "unknown") / \(pad.productCategory)")
+            self?.publishControllers()
+        }
+        NotificationCenter.default.addObserver(forName: .GCControllerDidDisconnect, object: nil, queue: .main) { [weak self] note in
+            guard let pad = note.object as? GCController else { return }
+            print("[fight-runner] controller disconnected: \(pad.vendorName ?? "unknown")")
+            self?.publishControllers()
+        }
+        GCController.startWirelessControllerDiscovery(completionHandler: {})
+        for controller in GCController.controllers() { controller.handlerQueue = .main }
+        controllerTimer = Timer.scheduledTimer(withTimeInterval: 1.0 / 60.0, repeats: true) { [weak self] _ in self?.publishControllers() }
+    }
+
+    private func publishControllers() {
+        let pads: [[String: Any]] = GCController.controllers().enumerated().map { index, controller in
+            var pad: [String: Any] = [
+                "index": index,
+                "id": controller.vendorName ?? controller.productCategory,
+                "category": controller.productCategory,
+                "connected": true,
+                "timestamp": ProcessInfo.processInfo.systemUptime * 1000,
+            ]
+            if let g = controller.extendedGamepad {
+                pad["axes"] = [g.leftThumbstick.xAxis.value, g.leftThumbstick.yAxis.value,
+                               g.rightThumbstick.xAxis.value, g.rightThumbstick.yAxis.value]
+                pad["buttons"] = [
+                    button(g.buttonA, "A"), button(g.buttonB, "B"), button(g.buttonX, "X"), button(g.buttonY, "Y"),
+                    button(g.leftShoulder, "LB"), button(g.rightShoulder, "RB"),
+                    button(g.leftTrigger, "LT"), button(g.rightTrigger, "RT"),
+                    button(g.dpad.up, "UP"), button(g.dpad.down, "DOWN"),
+                    button(g.dpad.left, "LEFT"), button(g.dpad.right, "RIGHT"),
+                ]
+            }
+            return pad
+        }
+        guard JSONSerialization.isValidJSONObject(pads),
+              let data = try? JSONSerialization.data(withJSONObject: pads),
+              let json = String(data: data, encoding: .utf8) else { return }
+        webView.evaluateJavaScript("window.__acNativeGamepads && window.__acNativeGamepads(\(json))")
+    }
+
+    private func button(_ input: GCControllerButtonInput, _ label: String) -> [String: Any] {
+        ["label": label, "pressed": input.isPressed, "value": input.value]
+    }
+
+    private func startReloadWatch() {
+        reloadTimer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in self?.pollReloadEndpoint() }
+        pollReloadEndpoint()
+    }
+
+    private func pollReloadEndpoint() {
+        guard let text = options.watchURL, let url = URL(string: text) else { return }
+        var request = URLRequest(url: url); request.cachePolicy = .reloadIgnoringLocalCacheData
+        URLSession.shared.dataTask(with: request) { [weak self] data, response, _ in
+            guard let self, let data,
+                  let http = response as? HTTPURLResponse, (200..<300).contains(http.statusCode) else { return }
+            let tag = http.value(forHTTPHeaderField: "ETag") ?? String(data: data, encoding: .utf8)
+            DispatchQueue.main.async {
+                defer { self.reloadTag = tag }
+                if let old = self.reloadTag, old != tag { self.reload() }
+            }
+        }.resume()
+    }
+
+    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
+        print("[fight-runner] ready: \(webView.url?.absoluteString ?? "unknown")")
+        publishControllers()
+    }
+
+    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
+        print("[fight-web] \(message.body)")
+    }
+
+    private static let hostScript = #"""
+    (() => {
+      window.acNativeHost = { platform: 'macOS', runner: 'fight', version: 1 };
+      window.__acNativeGamepads = (pads) => {
+        window.acNativeGamepads = pads;
+        window.dispatchEvent(new CustomEvent('ac-native-gamepads', { detail: pads }));
+        const out = document.getElementById('ac-native-controller-overlay');
+        if (out) out.textContent = pads.length ? pads.map(p => `${p.index + 1}: ${p.id}`).join('\n') : 'NO CONTROLLER';
+      };
+      addEventListener('DOMContentLoaded', () => {
+        const out = document.createElement('pre');
+        out.id = 'ac-native-controller-overlay'; out.textContent = 'NO CONTROLLER';
+        out.style.cssText = 'position:fixed;right:12px;bottom:12px;z-index:2147483647;margin:0;padding:7px 9px;background:#0009;color:#fff;font:11px/1.3 monospace;pointer-events:none';
+        document.documentElement.appendChild(out);
+      });
+      const original = console.log;
+      console.log = (...args) => { original(...args); try { webkit.messageHandlers.acNative.postMessage(args.map(String).join(' ')); } catch (_) {} };
+    })();
+    """#
+}
+
+private let application = NSApplication.shared
+private let runner = Runner()
+application.delegate = runner
+application.setActivationPolicy(.regular)
+application.activate(ignoringOtherApps: true)
+application.run()