diff --git a/toolbar/hermes_bridge.shelf b/toolbar/hermes_bridge.shelf
index 5c9f59b..3de9b51 100644
--- a/toolbar/hermes_bridge.shelf
+++ b/toolbar/hermes_bridge.shelf
@@ -1,12 +1,35 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <shelfDocument>
+  <!-- This file contains definitions of shelves, toolbars, and tools.
+ It should not be hand-edited when it is being used by the application.
+ Note, that two definitions of the same element are not allowed in
+ a single file. -->
+
   <toolshelf name="hermes_bridge" label="Hermes Bridge">
     <memberTool name="hermes_bridge_dialog"/>
   </toolshelf>
+
   <tool name="hermes_bridge_dialog" label="Hermes Bridge" icon="MISC_python">
     <helpText><![CDATA[Open the Hermes Bridge control panel.
 Manage port, open/close the bridge, copy connection info.]]></helpText>
-    <script scriptType="python"><![CDATA[
+    <script scriptType="python"><![CDATA["""
+Hermes Bridge - Houdini panel to open/close an hscript command port so an
+external AI agent ("Hermes") can connect to this Houdini session.
+
+Design notes (why this version differs from the old one):
+- Port status is checked with a real socket connect, not by parsing
+  hou.hscript() text output. Text parsing was fragile and caused
+  bridge_is_open() to silently misreport state.
+- The toggle button's signal is connected BEFORE the first _refresh(),
+  so a failed status check can never leave the button dead with no
+  handler attached.
+- Defaults to binding 127.0.0.1 (localhost-only). Binding 0.0.0.0 opens
+  an unauthenticated command port to the whole network - anyone who can
+  reach the port can run hscript/Python inside your Houdini session.
+  There's an explicit opt-in checkbox for network exposure instead of
+  making that the default.
+"""
+
 from PySide6 import QtWidgets, QtCore, QtGui
 import hou
 import socket
@@ -15,26 +38,8 @@ import os
 
 CONFIG_FILE = os.path.join(hou.homeHoudiniDirectory(), "hermes_bridge.json")
 DEFAULT_PORT = 12345
+CONNECT_TIMEOUT = 0.25  # seconds, for the local socket probe
 
-def load_config():
-    try:
-        with open(CONFIG_FILE) as f:
-            return json.load(f)
-    except Exception:
-        return {"port": DEFAULT_PORT}
-
-def save_config(cfg):
-    with open(CONFIG_FILE, "w") as f:
-        json.dump(cfg, f, indent=2)
-
-def bridge_is_open(port):
-    try:
-        out = hou.hscript("openport")[0]
-    except Exception:
-        return False
-    return f"Port {port} is open" in out
-
-# ── Styles ──────────────────────────────────────────
 STYLE_CONNECTED = (
     "QPushButton {"
     "  background: #5c1a1a; color: #ff7777;"
@@ -48,24 +53,68 @@ STYLE_DISCONNECTED = (
     "  padding: 12px; font-size: 15px; font-weight: bold; }"
 )
 
+
+def load_config():
+    try:
+        with open(CONFIG_FILE) as f:
+            cfg = json.load(f)
+    except Exception:
+        cfg = {}
+    cfg.setdefault("port", DEFAULT_PORT)
+    cfg.setdefault("expose_network", False)
+    return cfg
+
+
+def save_config(cfg):
+    try:
+        with open(CONFIG_FILE, "w") as f:
+            json.dump(cfg, f, indent=2)
+    except Exception as e:
+        hou.ui.setStatusMessage(f"Hermes Bridge: could not save config ({e})",
+                                 severity=hou.severityType.Warning)
+
+
+def bridge_is_open(port):
+    """Check via an actual TCP connect attempt to 127.0.0.1:port.
+    Works regardless of whether the listener is bound to 127.0.0.1 or
+    0.0.0.0, since both accept loopback connections."""
+    try:
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            s.settimeout(CONNECT_TIMEOUT)
+            return s.connect_ex(("127.0.0.1", port)) == 0
+    except OSError:
+        return False
+
+
 class HermesBridgeWindow(QtWidgets.QWidget):
     def __init__(self, parent=None):
         super().__init__(parent)
         self.cfg = load_config()
-        self.port = self.cfg.get("port", DEFAULT_PORT)
+        self.port = self.cfg["port"]
+        self.expose_network = self.cfg["expose_network"]
         self.hostname = socket.gethostname()
+
         self._build_ui()
-        # Connect signals FIRST — _refresh may throw but button must work
+
+        # Connect signals BEFORE the first refresh. If a status check
+        # ever throws, the button still has its handler attached.
         self.btn_toggle.released.connect(self._toggle)
+        self.port_spin.valueChanged.connect(self._on_port_changed)
+        self.chk_network.toggled.connect(self._on_network_toggled)
+        self.btn_copy.clicked.connect(self._copy)
+
         self._refresh()
 
+    # ---------- UI ----------
+
     def _build_ui(self):
         self.setWindowTitle("Hermes Bridge")
-        self.setMinimumWidth(420)
+        self.setMinimumWidth(440)
 
         self.setStyleSheet("""
             QWidget { background: #1e1e1e; color: #e0e0e0; font-size: 13px; }
             QLabel#title { font-size: 16px; font-weight: bold; color: #fff; }
+            QLabel#hint { color: #888; font-size: 11px; }
             QPushButton#btnCopy { background: #1565c0; color: #fff;
                 border: none; border-radius: 4px; padding: 8px 16px; font-weight: bold; }
             QPushButton#btnCopy:hover { background: #1976d2; }
@@ -73,6 +122,7 @@ class HermesBridgeWindow(QtWidgets.QWidget):
                        padding: 5px 8px; border-radius: 3px; }
             QLineEdit { background: #2d2d2d; border: 1px solid #555; color: #aaa;
                         padding: 5px 8px; border-radius: 3px; }
+            QCheckBox { spacing: 8px; }
         """)
 
         layout = QtWidgets.QVBoxLayout(self)
@@ -92,13 +142,24 @@ class HermesBridgeWindow(QtWidgets.QWidget):
         self.port_spin.setRange(1024, 65535)
         self.port_spin.setValue(self.port)
         self.port_spin.setFixedWidth(100)
-        self.port_spin.valueChanged.connect(self._on_port_changed)
         port_row.addWidget(self.port_spin)
         port_row.addStretch()
         layout.addLayout(port_row)
 
+        self.chk_network = QtWidgets.QCheckBox(
+            "Für andere Rechner im Netzwerk freigeben (bindet 0.0.0.0)")
+        self.chk_network.setChecked(self.expose_network)
+        layout.addWidget(self.chk_network)
+
+        hint = QtWidgets.QLabel(
+            "Achtung: Der Command-Port hat keine Authentifizierung. "
+            "Netzwerkfreigabe erlaubt jedem im Netz, Befehle in dieser "
+            "Houdini-Session auszuführen.")
+        hint.setObjectName("hint")
+        hint.setWordWrap(True)
+        layout.addWidget(hint)
+
         self.btn_toggle = QtWidgets.QPushButton()
-        self.btn_toggle.setObjectName("btnToggle")
         layout.addWidget(self.btn_toggle)
 
         layout.addWidget(QtWidgets.QLabel("Tell Hermes:"))
@@ -108,16 +169,25 @@ class HermesBridgeWindow(QtWidgets.QWidget):
         prompt_row.addWidget(self.prompt_field)
         self.btn_copy = QtWidgets.QPushButton("Copy")
         self.btn_copy.setObjectName("btnCopy")
-        self.btn_copy.clicked.connect(self._copy)
         prompt_row.addWidget(self.btn_copy)
         layout.addLayout(prompt_row)
         layout.addStretch()
 
+    # ---------- state / refresh ----------
+
     def _refresh(self):
-        is_open = bridge_is_open(self.port)
+        try:
+            is_open = bridge_is_open(self.port)
+        except Exception as e:
+            is_open = False
+            hou.ui.setStatusMessage(f"Hermes Bridge: status check failed ({e})",
+                                     severity=hou.severityType.Warning)
+
+        display_host = self.hostname if self.expose_network else "localhost"
+
         if is_open:
             self.status_label.setText(
-                f"\u25cf  Connected \u2014 {self.hostname}:{self.port}")
+                f"\u25cf  Connected \u2014 {display_host}:{self.port}")
             self.status_label.setStyleSheet(
                 "color: #4caf50; font-size: 14px; font-weight: bold;")
             self.btn_toggle.setText("Close Bridge")
@@ -128,46 +198,78 @@ class HermesBridgeWindow(QtWidgets.QWidget):
                 "color: #ff5555; font-size: 14px; font-weight: bold;")
             self.btn_toggle.setText("Open Bridge")
             self.btn_toggle.setStyleSheet(STYLE_DISCONNECTED)
+
+        # Can't change the bind scope of a port that's already listening
+        # without reopening it, so lock the controls while connected.
+        self.port_spin.setEnabled(not is_open)
+        self.chk_network.setEnabled(not is_open)
+
         self.prompt_field.setText(
             f"Hey Hermes, I have a Houdini session running "
-            f"on {self.hostname} (port {self.port}).")
+            f"on {display_host} (port {self.port}).")
+
+    # ---------- actions ----------
 
     def _toggle(self):
+        # Defer to the next event loop cycle to avoid re-entrancy issues
+        # with hou.hscript() inside a Qt signal handler.
+        QtCore.QTimer.singleShot(0, self._execute_toggle)
+
+    def _execute_toggle(self):
         try:
             if bridge_is_open(self.port):
                 hou.hscript(f"closeport {self.port}")
             else:
-                hou.hscript(f"closeport {self.port}")
-                hou.hscript(f"openport {self.port} 0.0.0.0")
-            self._refresh()
+                hou.hscript(f"closeport {self.port}")  # clear any stale state
+                # openport takes no positional host arg. IP restriction is
+                # done via -i ipmask. Default mask "+.+.+.+" already means
+                # "local machine only", so we only need -i when opting in
+                # to network exposure.
+                if self.expose_network:
+                    cmd = f"openport -i *.*.*.* {self.port}"
+                else:
+                    cmd = f"openport {self.port}"
+                out, err = hou.hscript(cmd)
+                if err:
+                    raise RuntimeError(err.strip())
         except Exception as e:
             hou.ui.displayMessage(
                 f"Toggle failed: {e}",
                 severity=hou.severityType.Error,
                 title="Hermes Bridge")
+        finally:
+            self._refresh()
 
     def _on_port_changed(self, value):
-        was_open = bridge_is_open(self.port)
-        if was_open:
-            hou.hscript(f"closeport {self.port}")
+        if bridge_is_open(self.port):
+            # Don't silently move a live port out from under the user.
+            self.port_spin.blockSignals(True)
+            self.port_spin.setValue(self.port)
+            self.port_spin.blockSignals(False)
+            hou.ui.displayMessage(
+                "Close the bridge before changing the port.",
+                title="Hermes Bridge")
+            return
         self.port = value
         self.cfg["port"] = value
         save_config(self.cfg)
-        if was_open:
-            hou.hscript(f"openport {self.port} 0.0.0.0")
+        self._refresh()
+
+    def _on_network_toggled(self, checked):
+        self.expose_network = checked
+        self.cfg["expose_network"] = checked
+        save_config(self.cfg)
         self._refresh()
 
     def _copy(self):
-        QtWidgets.QApplication.clipboard().setText(
-            self.prompt_field.text())
+        QtWidgets.QApplication.clipboard().setText(self.prompt_field.text())
         self.btn_copy.setText("\u2713 Copied!")
-        QtCore.QTimer.singleShot(2000,
-            lambda: self.btn_copy.setText("Copy"))
+        QtCore.QTimer.singleShot(2000, lambda: self.btn_copy.setText("Copy"))
 
-# ── Keep alive via hou.session ──
+
+# Keep the window alive via hou.session so it isn't garbage-collected.
 win = HermesBridgeWindow()
 hou.session.hermes_bridge_win = win
-win.show()
-]]></script>
+win.show()]]></script>
   </tool>
 </shelfDocument>