diff --git a/mash.yaml b/mash.yaml
new file mode 100644
index 0000000..b8a389c
--- /dev/null
+++ b/mash.yaml
@@ -0,0 +1,11 @@
+# An example config file for MaSH
+
+services:
+  philips-hue:
+    ip: 192.168.178.42
+
+rooms:
+  - name: Office
+  - name: Hallway
+    adjacent:
+      - Office
diff --git a/requirements.txt b/requirements.txt
index 27dcd81..01ecf54 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,12 @@
 smbus2
 vl53l1x
 
+# To parse the config file
+pyyaml
+
+# To hot reload the config file
+watchdog
+
 # For Philips Hue Counter
 phue
 
diff --git a/src/models/devices.py b/src/models/devices.py
new file mode 100644
index 0000000..041af03
--- /dev/null
+++ b/src/models/devices.py
@@ -0,0 +1,39 @@
+import abc
+
+from models.light import LightColor
+
+class GenericDevice:
+    """A generic device."""
+    def __init__(self, name: str):
+        self.name = name
+
+
+class SwitchDevice(GenericDevice):
+    """Abstract device that can be turned on and off."""
+
+    def toggle(self):
+        self.is_on = not self.is_on
+
+    @property
+    @abc.abstractmethod
+    def is_on(self) -> bool:
+        raise NotImplementedError
+
+    @is_on.setter
+    @abc.abstractmethod
+    def is_on(self, is_on: bool):
+        raise NotImplementedError
+
+
+class LightDevice(SwitchDevice):
+    """Abstract device that can be turned on and off and has a color."""
+
+    @property
+    @abc.abstractmethod
+    def color(self) -> LightColor:
+        raise NotImplementedError
+
+    @color.setter
+    @abc.abstractmethod
+    def color(self, color: LightColor):
+        raise NotImplementedError
diff --git a/src/models/groups.py b/src/models/groups.py
new file mode 100644
index 0000000..e0f0e2d
--- /dev/null
+++ b/src/models/groups.py
@@ -0,0 +1,71 @@
+from models.helper import filter_devices
+from models.devices import GenericDevice, LightDevice, SwitchDevice
+from models.light import LightColor, LightScene
+
+
+class DeviceGroup(LightDevice):
+    """A group of devices that allows group operations."""
+
+    def __init__(self, devices: list[GenericDevice]):
+        self._devices = devices
+
+    @property
+    def devices(self) -> list[GenericDevice]:
+        return self._devices
+
+    @property
+    def switches(self) -> list[SwitchDevice]:
+        return filter_devices(self.devices, SwitchDevice)
+
+    @property
+    def lights(self) -> list[LightDevice]:
+        return filter_devices(self.devices, LightDevice)
+
+    @property
+    def is_on(self) -> bool:
+        """Returns true if any device is on."""
+        return any(device.is_on for device in self.switches)
+
+    @is_on.setter
+    def is_on(self, is_on: bool):
+        """Sets all devices to the same state."""
+        for device in self.switches:
+            device.is_on = is_on
+
+    @property
+    def color(self) -> LightColor:
+        """Returns the color of the first light in the group."""
+        return self.lights[0].color
+
+    @color.setter
+    def color(self, color: LightColor):
+        """Sets all lights in the group to the same color."""
+        for device in self.lights:
+            device.color = color
+
+    @property
+    def scene(self) -> LightScene:
+        """Returns the current scene of the group."""
+        return LightScene(self.name, {device: device.color for device in self.lights})
+
+
+class Room(DeviceGroup):
+    """A group of devices that has additional properties a can be seen as a room."""
+
+    def __init__(self, name: str, devices: list[GenericDevice], people_count: int = 0):
+        """
+        Args:
+            name (str): Name of the room.
+            devices (list[GenericDevice]): Devices in this room.
+            people_count (int, optional): Number of people in this room. Defaults to 0.
+        """
+        super().__init__(devices)
+        self.name = name
+        self._people_count = people_count
+
+    @property
+    def people_count(self) -> int:
+        return self._people_count
+
+    def __str__(self):
+        return self.name
diff --git a/src/models/helper.py b/src/models/helper.py
new file mode 100644
index 0000000..52fe107
--- /dev/null
+++ b/src/models/helper.py
@@ -0,0 +1,10 @@
+from typing import TypeVar
+from models.devices import GenericDevice, LightDevice, SwitchDevice
+
+
+DEVICE_TYPE = TypeVar("DEVICE_TYPE", type(GenericDevice), type(SwitchDevice), type(LightDevice))
+
+
+def filter_devices(devices: list[GenericDevice], type: DEVICE_TYPE) -> list[DEVICE_TYPE]:
+    """Filters out devices that are not of a specific type."""
+    return [device for device in devices if isinstance(device, DEVICE_TYPE)]
diff --git a/src/models/light.py b/src/models/light.py
new file mode 100644
index 0000000..0dd0e2e
--- /dev/null
+++ b/src/models/light.py
@@ -0,0 +1,24 @@
+from models.devices import LightDevice
+
+
+class LightColor:
+    """The color of a light source."""
+
+    def __init__(self, red: int, green: int, blue: int, is_on: bool = True):
+        self.red = red
+        self.green = green
+        self.blue = blue
+        self.is_on = is_on
+
+
+class LightScene:
+    """A scene describing a state of a collection of light sources."""
+
+    def __init__(self, name: str, device_colors: dict[LightDevice, LightColor]):
+        self.name = name
+        self.device_colors = device_colors
+    
+    def set_scene(self):
+        """Sets the scene on all devices."""
+        for device, color in self.device_colors.items():
+            device.color = color