State objects
Your devicesA device is a model representing a physical or logical unit that contains entities. are represented in Home Assistant as entities. The entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] will write their current stateThe state holds the information of interest of an entity, for example, if a light is on or off. Each entity has exactly one state and the state only holds one value at a time. However, entities can store attributes related to that state such as brightness, color, or a unit of measurement. [Learn more] to the state machine for other entities/templates/frontend to access. States are a current representation of the entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].
If you overwrite a state via the states dev tool or the API, it will not impact the actual device. If the device state is being polled, it will overwrite the state in the state machine the next polling.
All states will always have an entity id, a state and a timestamp when last updated and last changed.
| Field | Description |
|---|---|
state.state |
String representation of the current state of the entity. Example off. |
state.entity_id |
Entity ID. Format: <domain>.<object_id>. Example: light.kitchen. |
state.domain |
Domain of the entity. Example: light. |
state.object_id |
Object ID of entity. Example: kitchen. |
state.name |
Name of the entity. Based on friendly_name attribute with fall back to object ID. Example: Kitchen Ceiling. |
state.last_changed |
Time the state changed in the state machine in UTC time. This is not updated if only state attributes change. Example: 2017-10-28 08:13:36.715874+00:00. |
state.last_reported |
Time the state was written to the state machine in UTC time. This timestamp is updated regardless of any change to the state or a state attribute. Example: 2017-10-28 08:13:36.715874+00:00. |
state.last_updated |
Time the state or state attributes changed in the state machine in UTC time. This is not updated if neither state nor state attributes changed. Example: 2017-10-28 08:13:36.715874+00:00. |
state.attributes |
A dictionary with extra attributes related to the current state. |
state.context |
A dictionary with extra attributes related to the context of the state. |
Attributes
The attributes of an entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] are optional.There are a few attributes that are available on all entities, such as friendly_name and icon. In addition to those, each integration has its own attributes to represent extra state data about the entity. For example, the light integration has attributes for the current brightness and color of the light. When an attribute is not available, Home Assistant will not write it to the state.
When using templates, attributes will be available by their name. For example state.attributes.assumed_state.
| Attribute | Description |
|---|---|
friendly_name |
Name of the entity. Example: Kitchen Ceiling. |
icon |
Icon to use for the entity in the frontend. Example: mdi:home. |
entity_picture |
URL to a picture that should be used instead of showing the domain icon. Example: http://example.com/picture.jpg. |
assumed_state |
Boolean if the current state is an assumption. More info Example: True. |
unit_of_measurement |
The unit of measurement the state is expressed in. Used for grouping graphs or understanding the entity. Example: °C. |
When an attribute contains spaces, you can retrieve it like this: state_attr('sensor.livingroom', 'Battery numeric').
Context
Context is used to tie eventsAn event is when something happens. [Learn more] and statesThe state holds the information of interest of an entity, for example, if a light is on or off. Each entity has exactly one state and the state only holds one value at a time. However, entities can store attributes related to that state such as brightness, color, or a unit of measurement. [Learn more] together in Home Assistant. Whenever an automationAutomations in Home Assistant allow you to automatically respond to things that happen in and around your home. [Learn more] or user interaction causes states to change, a new context is assigned. This context will be attached to all events and states that happen as result of the change.
| Field | Description |
|---|---|
context_id |
Unique identifier for the context. |
user_id |
Unique identifier of the user that started the change. Will be None if the action was not started by a user (for example, started by an automation). |
parent_id |
Unique identifier of the parent context that started the change, if available. For example, if an automation is triggered, the context of the trigger will be set as parent. |