seems to work

apps/homekit/accessories/contact.py

@@ -0,0 +1,48 @@
+"""
+Contact Sensor Accessory Implementation for HomeKit
+
+Implements contact sensor (window/door sensors):
+- ContactSensorState (read-only): 0=Detected, 1=Not Detected
+"""
+
+from pyhap.accessory import Accessory
+from pyhap.const import CATEGORY_SENSOR
+
+
+class ContactAccessory(Accessory):
+    """Contact sensor for doors and windows."""
+    
+    category = CATEGORY_SENSOR
+    
+    def __init__(self, driver, device, api_client, display_name=None, *args, **kwargs):
+        """
+        Initialize the contact sensor accessory.
+        
+        Args:
+            driver: HAP driver instance
+            device: Device object from DeviceRegistry
+            api_client: ApiClient for sending commands
+            display_name: Optional display name (defaults to device.friendly_name)
+        """
+        name = display_name or device.friendly_name or device.name
+        super().__init__(driver, name, *args, **kwargs)
+        self.device = device
+        self.api_client = api_client
+        
+        # Add ContactSensor service
+        self.contact_service = self.add_preload_service('ContactSensor')
+        
+        # Get ContactSensorState characteristic
+        self.contact_state_char = self.contact_service.get_characteristic('ContactSensorState')
+        
+        # Initialize with "not detected" (closed)
+        self.contact_state_char.set_value(1)
+    
+    def update_state(self, state_payload):
+        """Update state from API event."""
+        if "contact" in state_payload:
+            # API sends: "open" or "closed"
+            # HomeKit: 0=Contact Detected (closed), 1=Contact Not Detected (open)
+            is_open = state_payload["contact"] == "open"
+            homekit_state = 1 if is_open else 0
+            self.contact_state_char.set_value(homekit_state)