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Example app

This application shows basic capabilities of the HassModel API of NetDaemon. It has a single file ExampleApp.cs that contains the app logic. This example uses the code generation capability of HassModel explained here.


using System;
using System.Reactive.Linq;
using NetDaemon.AppModel;
using NetDaemon.HassModel;
using HomeAssistantGenerated;

public class ExampleAppHaContext
public ExampleAppHaContext(IHaContext ha)
var entities = new Entities(ha);

.Where(e => e.New.IsOn())
.Subscribe(_ =>entities.Light.Office.TurnOn());

The NetDaemonAppAttribute


By decorating a class with the NetDaemonAppAttribute it is registered as an application to be loaded by NetDaemon.

NetDaemon will create a helper in Home Assistant. By default, the helper is named:


The app name will be converted to snake casing (i.e: HelloWorld -> hello_world)

When you want to choose your own name you can make use of the Id parameter like:

[NetDaemonApp(Id = "appname")]

Netdaemon will replace {namespace}_appname with your given Id

The constructor

public ExampleAppHaContext(IHaContext ha)

When the application is (re-)started a new instance of the class is created by calling its constructor. This constructor will receive constructor arguments by using the standard .NET dependency injection mechanism. In this example the constructor receives an IHaContext interface which provides basic methods for interacting with Home Assistant.

The constructor can be used to do initialization of your application. Never block the constructor! Typically here you configure what should happen when a state changes or run a function every minute for example. If you need to do asynchronous initialization of your application this can be done by implementing IAsyncInitializable


        var entities = new Entities(ha);

.Where(e => e.New.IsOn())
.Subscribe(_ => entities.Light.Office.TurnOn());
new Entities(ha)Creates an Instance of the generated Entities class that provides strongly typed access to all your HA entities
entities.BinarySensor.OfficeMotionSelects the binary_sensor.office_motion entity from Home Assistant
StateChanges()Respond to changes of the state of this motion sensor
WhereFIlter which state changes we are interested in, int this case when the sensor state becomes 'on'
SubscribeCalls any code/action when the criteria is met
TurnOff()Turns off the lights in the office using another generated entity and a generated service method

Creating and updating Home Assistant entities

If you want to create entities from NetDaemon, set their state attributes, then check out the MQTT Entity Manager documentation

Real-world example apps

Please check out the apps being developed for NetDaemon. Since documentation is still lacking behind it would be best to look at real code 😊

@helto4realTomas NetDaemon apps running in production (V4)
@FrankBakkerNlHassModel examples by Frank the author of HassModel API
@KennetjuhKennetjuh's NetDaemon implementation (V4)
@vinnie1234Vincent's NetDaemon implementation (V4)
@leosperryLeonard's NetDaemon implementation (V3)
@pockybum522David's NetDaemon apps as used Daily (V4)