diff --git a/apps/abstraction/main.py b/apps/abstraction/main.py
index 711b902..a05272a 100644
--- a/apps/abstraction/main.py
+++ b/apps/abstraction/main.py
@@ -16,10 +16,14 @@ from aiomqtt import Client
 from pydantic import ValidationError
 
 from packages.home_capabilities import LightState, ThermostatState
+from apps.abstraction.transformation import (
+    transform_abstract_to_vendor,
+    transform_vendor_to_abstract
+)
 
 # Configure logging
 logging.basicConfig(
-    level=logging.INFO,
+    level=logging.DEBUG,
     format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
 )
 logger = logging.getLogger(__name__)
@@ -127,6 +131,7 @@ async def handle_abstract_set(
     mqtt_client: Client,
     device_id: str,
     device_type: str,
+    device_technology: str,
     vendor_topic: str,
     payload: dict[str, Any]
 ) -> None:
@@ -136,21 +141,22 @@ async def handle_abstract_set(
         mqtt_client: MQTT client instance
         device_id: Device identifier
         device_type: Device type (e.g., 'light', 'thermostat')
+        device_technology: Technology identifier (e.g., 'zigbee2mqtt')
         vendor_topic: Vendor-specific SET topic
         payload: Message payload
     """
     # Extract actual payload (remove type wrapper if present)
-    vendor_payload = payload.get("payload", payload)
+    abstract_payload = payload.get("payload", payload)
     
     # Validate payload based on device type
     try:
         if device_type == "light":
             # Validate light SET payload (power and/or brightness)
-            LightState.model_validate(vendor_payload)
+            LightState.model_validate(abstract_payload)
         elif device_type == "thermostat":
             # For thermostat SET: only allow mode and target fields
             allowed_set_fields = {"mode", "target"}
-            invalid_fields = set(vendor_payload.keys()) - allowed_set_fields
+            invalid_fields = set(abstract_payload.keys()) - allowed_set_fields
             if invalid_fields:
                 logger.warning(
                     f"Thermostat SET {device_id} contains invalid fields {invalid_fields}, "
@@ -159,11 +165,14 @@ async def handle_abstract_set(
                 return
             
             # Validate against ThermostatState (current/battery/window_open are optional)
-            ThermostatState.model_validate(vendor_payload)
+            ThermostatState.model_validate(abstract_payload)
     except ValidationError as e:
         logger.error(f"Validation failed for {device_type} SET {device_id}: {e}")
         return
     
+    # Transform abstract payload to vendor-specific format
+    vendor_payload = transform_abstract_to_vendor(device_type, device_technology, abstract_payload)
+    
     vendor_message = json.dumps(vendor_payload)
     
     logger.info(f"→ vendor SET {device_id}: {vendor_topic} ← {vendor_message}")
@@ -175,6 +184,7 @@ async def handle_vendor_state(
     redis_client: aioredis.Redis,
     device_id: str,
     device_type: str,
+    device_technology: str,
     payload: dict[str, Any],
     redis_channel: str = "ui:updates"
 ) -> None:
@@ -185,23 +195,27 @@ async def handle_vendor_state(
         redis_client: Redis client instance
         device_id: Device identifier
         device_type: Device type (e.g., 'light', 'thermostat')
-        payload: State payload
+        device_technology: Technology identifier (e.g., 'zigbee2mqtt')
+        payload: State payload (vendor-specific format)
         redis_channel: Redis channel for UI updates
     """
+    # Transform vendor-specific payload to abstract format
+    abstract_payload = transform_vendor_to_abstract(device_type, device_technology, payload)
+    
     # Validate state payload based on device type
     try:
         if device_type == "light":
-            LightState.model_validate(payload)
+            LightState.model_validate(abstract_payload)
         elif device_type == "thermostat":
             # Validate thermostat state: mode, target, current (required), battery, window_open
-            ThermostatState.model_validate(payload)
+            ThermostatState.model_validate(abstract_payload)
     except ValidationError as e:
         logger.error(f"Validation failed for {device_type} STATE {device_id}: {e}")
         return
     
     # Publish to abstract state topic (retained)
     abstract_topic = f"home/{device_type}/{device_id}/state"
-    abstract_message = json.dumps(payload)
+    abstract_message = json.dumps(abstract_payload)
     
     logger.info(f"← abstract STATE {device_id}: {abstract_topic} → {abstract_message}")
     await mqtt_client.publish(abstract_topic, abstract_message, qos=1, retain=True)
@@ -210,7 +224,7 @@ async def handle_vendor_state(
     ui_update = {
         "type": "state",
         "device_id": device_id,
-        "payload": payload,
+        "payload": abstract_payload,
         "ts": datetime.now(timezone.utc).isoformat()
     }
     redis_message = json.dumps(ui_update)
@@ -297,8 +311,9 @@ async def mqtt_worker(config: dict[str, Any], redis_client: aioredis.Redis) -> N
                             if device_id in devices:
                                 device = devices[device_id]
                                 vendor_topic = device["topics"]["set"]
+                                device_technology = device.get("technology", "unknown")
                                 await handle_abstract_set(
-                                    client, device_id, device_type, vendor_topic, payload
+                                    client, device_id, device_type, device_technology, vendor_topic, payload
                                 )
                     
                     # Check if this is a vendor STATE message
@@ -306,8 +321,10 @@ async def mqtt_worker(config: dict[str, Any], redis_client: aioredis.Redis) -> N
                         # Find device by vendor state topic
                         for device_id, device in devices.items():
                             if topic == device["topics"]["state"]:
+                                device_technology = device.get("technology", "unknown")
                                 await handle_vendor_state(
-                                    client, redis_client, device_id, device["type"], payload, redis_channel
+                                    client, redis_client, device_id, device["type"], 
+                                    device_technology, payload, redis_channel
                                 )
                                 break
                         
diff --git a/apps/abstraction/transformation.py b/apps/abstraction/transformation.py
new file mode 100644
index 0000000..5a0ac48
--- /dev/null
+++ b/apps/abstraction/transformation.py
@@ -0,0 +1,88 @@
+"""Payload transformation functions for vendor-specific device communication.
+
+This module provides transformation functions to translate between abstract
+home protocol payloads and vendor-specific device payloads.
+"""
+
+import logging
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+
+def transform_abstract_to_vendor(
+    device_type: str,
+    device_technology: str,
+    abstract_payload: dict[str, Any]
+) -> dict[str, Any]:
+    """Transform abstract payload to vendor-specific payload for SET commands.
+    
+    This function allows technology-specific transformations when sending commands
+    to devices. For example, different vendors might use different field names or
+    value formats for the same abstract concept.
+    
+    Args:
+        device_type: Type of device (e.g., 'light', 'thermostat')
+        device_technology: Technology identifier (e.g., 'zigbee2mqtt', 'tasmota')
+        abstract_payload: Abstract payload following home protocol
+        
+    Returns:
+        Vendor-specific payload for the device
+        
+    Example:
+        Input:  {'power': 'on', 'brightness': 75}
+        Output: {'state': 'ON', 'brightness': 75}  # hypothetical vendor format
+    """
+    logger.debug(
+        f"transform_abstract_to_vendor IN: type={device_type}, tech={device_technology}, "
+        f"payload={abstract_payload}"
+    )
+    
+    # TODO: Implement technology-specific transformations here
+    # Currently pass-through: return payload unchanged
+    vendor_payload = abstract_payload
+    
+    logger.debug(
+        f"transform_abstract_to_vendor OUT: type={device_type}, tech={device_technology}, "
+        f"payload={vendor_payload}"
+    )
+    return vendor_payload
+
+
+def transform_vendor_to_abstract(
+    device_type: str,
+    device_technology: str,
+    vendor_payload: dict[str, Any]
+) -> dict[str, Any]:
+    """Transform vendor-specific payload to abstract payload for STATE messages.
+    
+    This function allows technology-specific transformations when receiving state
+    updates from devices. For example, different vendors might report state using
+    different field names or value formats.
+    
+    Args:
+        device_type: Type of device (e.g., 'light', 'thermostat')
+        device_technology: Technology identifier (e.g., 'zigbee2mqtt', 'tasmota')
+        vendor_payload: Vendor-specific payload from the device
+        
+    Returns:
+        Abstract payload following home protocol
+        
+    Example:
+        Input:  {'state': 'ON', 'brightness': 75}  # hypothetical vendor format
+        Output: {'power': 'on', 'brightness': 75}
+    """
+    logger.debug(
+        f"transform_vendor_to_abstract IN: type={device_type}, tech={device_technology}, "
+        f"payload={vendor_payload}"
+    )
+    
+    # TODO: Implement technology-specific transformations here
+    # Currently pass-through: return payload unchanged
+    abstract_payload = vendor_payload
+    
+    logger.debug(
+        f"transform_vendor_to_abstract OUT: type={device_type}, tech={device_technology}, "
+        f"payload={abstract_payload}"
+    )
+    return abstract_payload
diff --git a/config/devices.yaml b/config/devices.yaml
index bacb9df..8fcb3de 100644
--- a/config/devices.yaml
+++ b/config/devices.yaml
@@ -16,7 +16,7 @@ devices:
   - device_id: test_lampe_1
     type: light
     cap_version: "light@1.2.0"
-    technology: zigbee2mqtt
+    technology: simulator
     features:
       power: true
       brightness: true
@@ -26,7 +26,7 @@ devices:
   - device_id: test_lampe_2
     type: light
     cap_version: "light@1.2.0"
-    technology: zigbee2mqtt
+    technology: simulator
     features:
       power: true
     topics:
@@ -35,7 +35,7 @@ devices:
   - device_id: test_lampe_3
     type: light
     cap_version: "light@1.2.0"
-    technology: zigbee2mqtt
+    technology: simulator
     features:
       power: true
       brightness: true
@@ -45,7 +45,7 @@ devices:
   - device_id: test_thermo_1
     type: thermostat
     cap_version: "thermostat@2.0.0"
-    technology: zigbee2mqtt
+    technology: simulator
     features:
       mode: false
       target: true