diff --git a/js/misc/portalHandlers.js b/js/misc/portalHandlers.js
new file mode 100644
index 0000000000..de85235cd0
--- /dev/null
+++ b/js/misc/portalHandlers.js
@@ -0,0 +1,88 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+
+const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
+const Cinnamon = imports.gi.Cinnamon;
+
+const XdgAppState = {
+    BACKGROUND: 0, // window.is_hidden
+    RUNNING:    1, // window visible
+    ACTIVE:     2  // window focused
+}
+
+const CinnamonPortalIface =
+    '<node> \
+        <interface name="org.cinnamon.PortalHandlers"> \
+            <method name="GetAppStates"> \
+                <arg type="a{sv}" direction="out" name="apps" /> \
+            </method> \
+            <signal name="RunningAppsChanged"/> \
+        </interface> \
+    </node>';
+
+
+var CinnamonPortalHandler = class CinnamonPortalHandler {
+    constructor() {
+        this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(CinnamonPortalIface, this);
+        this._dbusImpl.export(Gio.DBus.session, '/org/Cinnamon');
+
+        this.running_apps = {}
+        Cinnamon.AppSystem.get_default().connect("app-state-changed", () => this.EmitRunningAppsChanged());
+        Cinnamon.WindowTracker.get_default().connect("notify::focus-app", () => this.EmitRunningAppsChanged());
+    }
+
+    EmitRunningAppsChanged() {
+        this._dbusImpl.emit_signal('RunningAppsChanged', null);
+    }
+
+    has_focus(app) {
+        const fwin = global.display.get_focus_window();
+        if (fwin == null) {
+            return false;
+        }
+
+        const app_windows = app.get_windows();
+        for (let w of app_windows) {
+            if (w == fwin) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /* org.freedesktop.impl.portal.Background.GetAppState:
+     * A big issue right now is that in X11, CinnamonAppSystem stops caring
+     * about an app if its windows are closed or *hidden* to tray, so our list
+     * here won't contain any background apps until this behavior is addressed. */
+    GetAppStates() {
+        const appsys = Cinnamon.AppSystem.get_default();
+        const running = appsys.get_running();
+        const apps = {}
+
+        for (let app of running) {
+            var id = null;
+
+            if (app.get_is_flatpak()) {
+                id = app.get_flatpak_app_id();
+            }
+            else
+            {
+                id = app.get_id();
+            }
+            if (app.get_n_windows() === 0) {
+                apps[id] = GLib.Variant.new_uint32(XdgAppState.BACKGROUND); // Can't happen currently.
+            } else {
+                if (this.has_focus(app)) {
+                    apps[id] = GLib.Variant.new_uint32(XdgAppState.ACTIVE);
+                }
+                else
+                {
+                    apps[id] = GLib.Variant.new_uint32(XdgAppState.RUNNING);
+                }
+            }
+        }
+
+        return new GLib.Variant("(a{sv})", [apps]);
+    }
+}
diff --git a/js/ui/main.js b/js/ui/main.js
index 30eed583ab..66b9f01e05 100644
--- a/js/ui/main.js
+++ b/js/ui/main.js
@@ -127,6 +127,7 @@ const InputMethod = imports.misc.inputMethod;
 const ScreenRecorder = imports.ui.screenRecorder;
 const {GesturesManager} = imports.ui.gestures.gesturesManager;
 const {MonitorLabeler} = imports.ui.monitorLabeler;
+const {CinnamonPortalHandler} = imports.misc.portalHandlers;
 
 var LAYOUT_TRADITIONAL = "traditional";
 var LAYOUT_FLIPPED = "flipped";
@@ -310,6 +311,7 @@ function start() {
 
     Clutter.get_default_backend().set_input_method(new InputMethod.InputMethod());
 
+    new CinnamonPortalHandler();
     cinnamonDBusService = new CinnamonDBus.CinnamonDBus();
     setRunState(RunState.STARTUP);