diff --git a/3rdparty/plog b/3rdparty/plog
index f4c22b0..914e799 160000
--- a/3rdparty/plog
+++ b/3rdparty/plog
@@ -1 +1 @@
-Subproject commit f4c22b03d5d3aa753cca8e716636ac4eb29b0917
+Subproject commit 914e799d2b08d790f5d04d1c46928586b3a41250
diff --git a/GPClient/CMakeLists.txt b/GPClient/CMakeLists.txt
index 9c52cdd..5387aa4 100644
--- a/GPClient/CMakeLists.txt
+++ b/GPClient/CMakeLists.txt
@@ -33,6 +33,8 @@ add_executable(gpclient
     gpclient.ui
     normalloginwindow.ui
     settingsdialog.ui
+    vpn_dbus.cpp
+    vpn_json.cpp
     resources.qrc
     ${gpclient_GENERATED_SOURCES}
 )
@@ -52,7 +54,7 @@ add_3rdparty(
 add_3rdparty(
     plog
     GIT_REPOSITORY https://github.com/SergiusTheBest/plog.git
-    GIT_TAG 1.1.5
+    GIT_TAG master
     CMAKE_ARGS
         -DPLOG_BUILD_SAMPLES=OFF
         -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
diff --git a/GPClient/gpclient.cpp b/GPClient/gpclient.cpp
index 76cfd58..a2741cb 100644
--- a/GPClient/gpclient.cpp
+++ b/GPClient/gpclient.cpp
@@ -11,9 +11,10 @@
 
 using namespace gpclient::helper;
 
-GPClient::GPClient(QWidget *parent)
+GPClient::GPClient(QWidget *parent, IVpn *vpn)
     : QMainWindow(parent)
     , ui(new Ui::GPClient)
+    , vpn(vpn)
     , settingsDialog(new SettingsDialog(this))
 {
     ui->setupUi(this);
@@ -25,14 +26,14 @@ GPClient::GPClient(QWidget *parent)
     setupSettings();
 
     // Restore portal from the previous settings
-    ui->portalInput->setText(settings::get("portal", "").toString());
+    this->portal(settings::get("portal", "").toString());
 
     // DBus service setup
-    vpn = new com::yuezk::qt::GPService("com.yuezk.qt.GPService", "/", QDBusConnection::systemBus(), this);
-    connect(vpn, &com::yuezk::qt::GPService::connected, this, &GPClient::onVPNConnected);
-    connect(vpn, &com::yuezk::qt::GPService::disconnected, this, &GPClient::onVPNDisconnected);
-    connect(vpn, &com::yuezk::qt::GPService::error, this, &GPClient::onVPNError);
-    connect(vpn, &com::yuezk::qt::GPService::logAvailable, this, &GPClient::onVPNLogAvailable);
+    QObject *ov = dynamic_cast<QObject*>(vpn);
+    connect(ov, SIGNAL(connected()), this, SLOT(onVPNConnected()));
+    connect(ov, SIGNAL(disconnected()), this, SLOT(onVPNDisconnected()));
+    connect(ov, SIGNAL(error(const &QString)), this, SLOT(onVPNError(const QString&)));
+    connect(ov, SIGNAL(logAvailable(const &QString)), this, SLOT(onVPNLogAvailable(const QString&)));
 
     // Initiallize the context menu of system tray.
     initSystemTrayIcon();
@@ -373,7 +374,11 @@ void GPClient::onGatewaySuccess(const QString &authCookie)
     PLOGI << "Gateway login succeeded, got the cookie " << authCookie;
 
     isQuickConnect = false;
-    vpn->connect(currentGateway().address(), portalConfig.username(), authCookie, settings::get("extraArgs", "").toString());
+    QList<QString> gatewayAddresses;
+    for (GPGateway &gw : allGateways()) {
+      gatewayAddresses.push_back(gw.address());
+    }
+    vpn->connect(currentGateway().address(), gatewayAddresses, portalConfig.username(), authCookie, settings::get("extraArgs", "").toString());
     ui->statusLabel->setText("Connecting...");
     updateConnectionStatus(VpnStatus::pending);
 }
@@ -410,6 +415,11 @@ QString GPClient::portal() const
     return input;
 }
 
+void GPClient::portal(QString p)
+{
+    ui->portalInput->setText(p);
+}
+
 bool GPClient::connected() const
 {
     const QString statusText = ui->statusLabel->text();
diff --git a/GPClient/gpclient.h b/GPClient/gpclient.h
index ae2eaf7..0578305 100644
--- a/GPClient/gpclient.h
+++ b/GPClient/gpclient.h
@@ -6,9 +6,9 @@
 #include <QtWidgets/QMenu>
 #include <QtWidgets/QPushButton>
 
-#include "gpserviceinterface.h"
 #include "portalconfigresponse.h"
 #include "settingsdialog.h"
+#include "vpn.h"
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class GPClient; }
@@ -19,12 +19,20 @@ class GPClient : public QMainWindow
     Q_OBJECT
 
 public:
-    GPClient(QWidget *parent = nullptr);
+    GPClient(QWidget *parent, IVpn *vpn);
     ~GPClient();
 
     void activate();
     void quit();
 
+    QString portal() const;
+    void portal(QString);
+
+    GPGateway currentGateway() const;
+    void setCurrentGateway(const GPGateway gateway);
+
+    void doConnect();
+
 private slots:
     void onSettingsButtonClicked();
     void onSettingsAccepted();
@@ -58,7 +66,7 @@ private:
     };
 
     Ui::GPClient *ui;
-    com::yuezk::qt::GPService *vpn;
+    IVpn *vpn;
 
     QSystemTrayIcon *systemTrayIcon;
     QMenu *contextMenu;
@@ -83,20 +91,15 @@ private:
     void populateGatewayMenu();
     void updateConnectionStatus(const VpnStatus &status);
 
-    void doConnect();
     void portalLogin();
     void tryGatewayLogin();
     void gatewayLogin();
 
-    QString portal() const;
     bool connected() const;
 
     QList<GPGateway> allGateways() const;
     void setAllGateways(QList<GPGateway> gateways);
 
-    GPGateway currentGateway() const;
-    void setCurrentGateway(const GPGateway gateway);
-
     void clearSettings();
 };
 #endif // GPCLIENT_H
diff --git a/GPClient/main.cpp b/GPClient/main.cpp
index 5344847..5e87ddc 100644
--- a/GPClient/main.cpp
+++ b/GPClient/main.cpp
@@ -3,24 +3,22 @@
 #include <QtCore/QDir>
 #include <QtCore/QStandardPaths>
 #include <plog/Log.h>
+#include <plog/Init.h>
 #include <plog/Appenders/ColorConsoleAppender.h>
+#include <plog/Formatters/TxtFormatter.h>
 
 #include "singleapplication.h"
 #include "gpclient.h"
+#include "vpn_dbus.h"
+#include "vpn_json.h"
 #include "enhancedwebview.h"
 #include "sigwatch.h"
 #include "version.h"
 
 int main(int argc, char *argv[])
 {
-    const QDir path = QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation) + "/GlobalProtect-openconnect";
-    const QString logFile = path.path() + "/gpclient.log";
-    if (!path.exists()) {
-        path.mkpath(".");
-    }
-
-    static plog::ColorConsoleAppender<plog::TxtFormatter> consoleAppender;
-    plog::init(plog::debug, logFile.toUtf8()).addAppender(&consoleAppender);
+    plog::ColorConsoleAppender<plog::TxtFormatter> consoleAppender(plog::streamStdErr);
+    plog::init(plog::debug, &consoleAppender);
 
     PLOGI << "GlobalProtect started, version: " << VERSION;
 
@@ -33,9 +31,35 @@ int main(int argc, char *argv[])
     SingleApplication app(argc, argv);
     app.setQuitOnLastWindowClosed(false);
 
-    GPClient w;
+    QCommandLineParser parser;
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.addPositionalArgument("server", "The URL of the VPN server. Optional.");
+    parser.addPositionalArgument("gateway", "The URL of the specific VPN gateway. Optional.");
+    parser.addOptions({
+      {"json", "Write the result of the handshake with the GlobalConnect server to stdout as JSON and terminate. Useful for scripting."},
+      {"now", "Do not show the dialog with the connect button; connect immediately instead."},
+    });
+    parser.process(app);
+
+    const QStringList positional = parser.positionalArguments();
+
+    IVpn *vpn = parser.isSet("json") // yes it leaks, but this is cleared on exit anyway
+      ? static_cast<IVpn*>(new VpnJson(nullptr)) // Print to stdout and exit
+      : static_cast<IVpn*>(new VpnDbus(nullptr)); // Contact GPService daemon via dbus
+    GPClient w(nullptr, vpn);
     w.show();
 
+    if (positional.size() > 0) {
+      w.portal(positional.at(0));
+    }
+    if (positional.size() > 1) {
+      GPGateway gw;
+      gw.setName(positional.at(1));
+      gw.setAddress(positional.at(1));
+      w.setCurrentGateway(gw);
+    }
+
     QObject::connect(&app, &SingleApplication::instanceStarted, &w, &GPClient::activate);
 
     UnixSignalWatcher sigwatch;
@@ -45,5 +69,12 @@ int main(int argc, char *argv[])
     sigwatch.watchForSignal(SIGHUP);
     QObject::connect(&sigwatch, &UnixSignalWatcher::unixSignal, &w, &GPClient::quit);
 
+    if (parser.isSet("now")) {
+      w.doConnect();
+    }
+    if (parser.isSet("json")) {
+      QObject::connect(static_cast<VpnJson*>(vpn), &VpnJson::connected, &w, &GPClient::quit);
+    }
+
     return app.exec();
 }
diff --git a/GPClient/vpn.h b/GPClient/vpn.h
new file mode 100644
index 0000000..eb26f33
--- /dev/null
+++ b/GPClient/vpn.h
@@ -0,0 +1,24 @@
+#ifndef VPN_H
+#define VPN_H
+#include <QtCore/QObject>
+#include <QtCore/QString>
+
+class IVpn
+{
+public:
+    virtual ~IVpn() = default;
+
+    virtual void connect(const QString &preferredServer, const QList<QString> &servers, const QString &username, const QString &passwd, const QString &extraArgs) = 0;
+    virtual void disconnect() = 0;
+    virtual int status() = 0;
+
+// signals: // SIGNALS
+//     virtual void connected();
+//     virtual void disconnected();
+//     virtual void error(const QString &errorMessage);
+//     virtual void logAvailable(const QString &log);
+};
+
+Q_DECLARE_INTERFACE(IVpn, "IVpn") // define this out of namespace scope
+
+#endif
diff --git a/GPClient/vpn_dbus.cpp b/GPClient/vpn_dbus.cpp
new file mode 100644
index 0000000..2983cd1
--- /dev/null
+++ b/GPClient/vpn_dbus.cpp
@@ -0,0 +1,13 @@
+#include "vpn_dbus.h"
+
+void VpnDbus::connect(const QString &preferredServer, const QList<QString> &servers, const QString &username, const QString &passwd, const QString &extraArgs) {
+    inner->connect(preferredServer, username, passwd, extraArgs);
+}
+
+void VpnDbus::disconnect() {
+    inner->disconnect();
+}
+
+int VpnDbus::status() {
+    return inner->status();
+}
diff --git a/GPClient/vpn_dbus.h b/GPClient/vpn_dbus.h
new file mode 100644
index 0000000..a66c86a
--- /dev/null
+++ b/GPClient/vpn_dbus.h
@@ -0,0 +1,33 @@
+#ifndef VPN_DBUS_H
+#define VPN_DBUS_H
+#include "vpn.h"
+#include "gpserviceinterface.h"
+
+class VpnDbus : public QObject, public IVpn
+{
+  Q_OBJECT
+  Q_INTERFACES(IVpn)
+
+private:
+  com::yuezk::qt::GPService *inner;
+
+public:
+  VpnDbus(QObject *parent) : QObject(parent) {
+    inner = new com::yuezk::qt::GPService("com.yuezk.qt.GPService", "/", QDBusConnection::systemBus(), this);
+    QObject::connect(inner, &com::yuezk::qt::GPService::connected, this, &VpnDbus::connected);
+    QObject::connect(inner, &com::yuezk::qt::GPService::disconnected, this, &VpnDbus::disconnected);
+    QObject::connect(inner, &com::yuezk::qt::GPService::error, this, &VpnDbus::error);
+    QObject::connect(inner, &com::yuezk::qt::GPService::logAvailable, this, &VpnDbus::logAvailable);
+  }
+
+  void connect(const QString &preferredServer, const QList<QString> &servers, const QString &username, const QString &passwd, const QString &extraArgs);
+  void disconnect();
+  int status();
+
+signals: // SIGNALS
+  void connected();
+  void disconnected();
+  void error(const QString &errorMessage);
+  void logAvailable(const QString &log);
+};
+#endif
diff --git a/GPClient/vpn_json.cpp b/GPClient/vpn_json.cpp
new file mode 100644
index 0000000..bfdcf7f
--- /dev/null
+++ b/GPClient/vpn_json.cpp
@@ -0,0 +1,24 @@
+#include "vpn_json.h"
+#include <QTextStream> 
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+
+void VpnJson::connect(const QString &preferredServer, const QList<QString> &servers, const QString &username, const QString &passwd, const QString &extraArgs) {
+    QJsonArray sl;
+    for (const QString &srv : servers) {
+      sl.push_back(QJsonValue(srv));
+    }
+    QJsonObject j;
+    j["server"] = preferredServer;
+    j["availableServers"] = sl;
+    j["cookie"] = passwd;
+    QTextStream(stdout) << QJsonDocument(j).toJson(QJsonDocument::Compact) << "\n";
+    emit connected();
+}
+
+void VpnJson::disconnect() { /* nop */ }
+
+int VpnJson::status() {
+    return 4; // disconnected
+}
diff --git a/GPClient/vpn_json.h b/GPClient/vpn_json.h
new file mode 100644
index 0000000..f577bee
--- /dev/null
+++ b/GPClient/vpn_json.h
@@ -0,0 +1,23 @@
+#ifndef VPN_JSON_H
+#define VPN_JSON_H
+#include "vpn.h"
+
+class VpnJson : public QObject, public IVpn
+{
+  Q_OBJECT
+  Q_INTERFACES(IVpn)
+
+public:
+  VpnJson(QObject *parent) : QObject(parent) {}
+
+  void connect(const QString &preferredServer, const QList<QString> &servers, const QString &username, const QString &passwd, const QString &extraArgs);
+  void disconnect();
+  int status();
+
+signals: // SIGNALS
+  void connected();
+  void disconnected();
+  void error(const QString &errorMessage);
+  void logAvailable(const QString &log);
+};
+#endif