home-assistant.io/source/_integrations/button.mqtt.markdown

---
title: "MQTT button"
description: "Instructions on how to integrate MQTT buttons into Home Assistant."
ha_category:
  - Button
ha_release: 2021.12
ha_iot_class: Configurable
ha_domain: mqtt
---

The `mqtt` button platform lets you send an MQTT message when the button is pressed in the frontend or the button press action is called. This can be used to expose some service of a remote device, for example reboot.

## Configuration

```yaml
# Example configuration.yaml entry
mqtt:
  - button:
      command_topic: "home/bedroom/switch1/reboot"
```

{% configuration %}
availability:
  description: A list of MQTT topics subscribed to receive availability (online/offline) updates. Must not be used together with `availability_topic`.
  required: false
  type: list
  keys:
    payload_available:
      description: The payload that represents the available state.
      required: false
      type: string
      default: online
    payload_not_available:
      description: The payload that represents the unavailable state.
      required: false
      type: string
      default: offline
    topic:
      description: An MQTT topic subscribed to receive availability (online/offline) updates.
      required: true
      type: string
    value_template:
      description: "Defines a [template](/docs/configuration/templating/#using-value-templates-with-mqtt) to extract device's availability from the `topic`. To determine the devices's availability result of this template will be compared to `payload_available` and `payload_not_available`."
      required: false
      type: template
availability_mode:
  description: When `availability` is configured, this controls the conditions needed to set the entity to `available`. Valid entries are `all`, `any`, and `latest`. If set to `all`, `payload_available` must be received on all configured availability topics before the entity is marked as online. If set to `any`, `payload_available` must be received on at least one configured availability topic before the entity is marked as online. If set to `latest`, the last `payload_available` or `payload_not_available` received on any configured availability topic controls the availability.
  required: false
  type: string
  default: latest
availability_template:
  description: "Defines a [template](/docs/configuration/templating/#using-value-templates-with-mqtt) to extract device's availability from the `availability_topic`. To determine the devices's availability result of this template will be compared to `payload_available` and `payload_not_available`."
  required: false
  type: template
availability_topic:
  description: The MQTT topic subscribed to receive availability (online/offline) updates. Must not be used together with `availability`.
  required: false
  type: string
command_template:
  description: Defines a [template](/docs/configuration/templating/#using-command-templates-with-mqtt) to generate the payload to send to `command_topic`.
  required: false
  type: template
command_topic:
  description: The MQTT topic to publish commands to trigger the button.
  required: true
  type: string
device:
  description: "Information about the device this button is a part of to tie it into the [device registry](https://developers.home-assistant.io/docs/en/device_registry_index.html). Only works when [`unique_id`](#unique_id) is set. At least one of identifiers or connections must be present to identify the device."
  required: false
  type: map
  keys:
    configuration_url:
      description: 'A link to the webpage that can manage the configuration of this device. Can be either an `http://`, `https://` or an internal `homeassistant://` URL.'
      required: false
      type: string
    connections:
      description: 'A list of connections of the device to the outside world as a list of tuples `[connection_type, connection_identifier]`. For example the MAC address of a network interface: `"connections": [["mac", "02:5b:26:a8:dc:12"]]`.'
      required: false
      type: list
    hw_version:
      description: The hardware version of the device.
      required: false
      type: string
    identifiers:
      description: A list of IDs that uniquely identify the device. For example a serial number.
      required: false
      type: [string, list]
    manufacturer:
      description: The manufacturer of the device.
      required: false
      type: string
    model:
      description: The model of the device.
      required: false
      type: string
    model_id:
      description: The model identifier of the device.
      required: false
      type: string
    name:
      description: The name of the device.
      required: false
      type: string
    serial_number:
      description: "The serial number of the device."
      required: false
      type: string
    suggested_area:
      description: 'Suggest an area if the device isn’t in one yet.'
      required: false
      type: string
    sw_version:
      description: The firmware version of the device.
      required: false
      type: string
    via_device:
      description: 'Identifier of a device that routes messages between this device and Home Assistant. Examples of such devices are hubs, or parent devices of a sub-device. This is used to show device topology in Home Assistant.'
      required: false
      type: string
device_class:
  description: The [type/class](/integrations/button/#device-class) of the button to set the icon in the frontend. The `device_class` can be `null`.
  required: false
  type: device_class
enabled_by_default:
  description: Flag which defines if the entity should be enabled when first added.
  required: false
  type: boolean
  default: true
encoding:
  description: The encoding of the published messages.
  required: false
  type: string
  default: "utf-8"
entity_category:
  description: The [category](https://developers.home-assistant.io/docs/core/entity#generic-properties) of the entity.
  required: false
  type: string
entity_picture:
  description: "Picture URL for the entity."
  required: false
  type: string
icon:
  description: "[Icon](/docs/configuration/customizing-devices/#icon) for the entity."
  required: false
  type: icon
json_attributes_template:
  description: "Defines a [template](/docs/configuration/templating/#using-value-templates-with-mqtt) to extract the JSON dictionary from messages received on the `json_attributes_topic`. Usage example can be found in [MQTT sensor](/integrations/sensor.mqtt/#json-attributes-template-configuration) documentation."
  required: false
  type: template
json_attributes_topic:
  description: The MQTT topic subscribed to receive a JSON dictionary payload and then set as sensor attributes. Usage example can be found in [MQTT sensor](/integrations/sensor.mqtt/#json-attributes-topic-configuration) documentation.
  required: false
  type: string
name:
  description: The name to use when displaying this button. Can be set to `null` if only the device name is relevant.
  required: false
  type: string
  default: MQTT Button
object_id:
  description: Used instead of `name` for automatic generation of `entity_id`
  required: false
  type: string
payload_available:
  description: The payload that represents the available state.
  required: false
  type: string
  default: online
payload_not_available:
  description: The payload that represents the unavailable state.
  required: false
  type: string
  default: offline
payload_press:
  description: The payload To send to trigger the button.
  required: false
  type: string
  default: "PRESS"
platform:
  description: Must be `button`. Only allowed and required in [MQTT auto discovery device messages](/integrations/mqtt/#device-discovery-payload).
  required: true
  type: string
qos:
  description: The maximum QoS level to be used when receiving and publishing messages.
  required: false
  type: integer
  default: 0
retain:
  description: If the published message should have the retain flag on or not.
  required: false
  type: boolean
  default: false
unique_id:
  description: An ID that uniquely identifies this button entity. If two buttons have the same unique ID, Home Assistant will raise an exception. Required when used with device-based discovery.
  required: false
  type: string
{% endconfiguration %}

{% important %}
Make sure that your topic matches exactly. `some-topic/` and `some-topic` are different topics.
{% endimportant %}

## Examples

In this section, you will find some real-life examples of how to use this feature.

### Full configuration

The example below shows a full configuration for a button.

```yaml
# Example configuration.yaml entry
mqtt:
  - button:
      unique_id: bedroom_switch_reboot_btn
      name: "Restart Bedroom Switch"
      command_topic: "home/bedroom/switch1/commands"
      payload_press: "restart"
      availability:
        - topic: "home/bedroom/switch1/available"
      qos: 0
      retain: false
      entity_category: "config"
      device_class: "restart"
```