MQTT Client Component ===================== .. seo:: :description: Instructions for setting up the MQTT client to communicate with the local network in ESPHome. :image: mqtt.png :keywords: MQTT The MQTT Client Component sets up the MQTT connection to your broker and is currently required for ESPHome to work. In most cases, you will just be able to copy over the `MQTT section `__ of your Home Assistant configuration. .. code-block:: yaml # Example configuration entry mqtt: broker: 10.0.0.2 username: livingroom password: MyMQTTPassword Configuration variables: ------------------------ - **broker** (**Required**, string): The host of your MQTT broker. - **port** (*Optional*, int): The port to connect to. Defaults to 1883. - **username** (*Optional*, string): The username to use for authentication. Empty (the default) means no authentication. - **password** (*Optional*, string): The password to use for authentication. Empty (the default) means no authentication. - **client_id** (*Optional*, string): The client id to use for opening connections. See :ref:`mqtt-defaults` for more information. - **discovery** (*Optional*, boolean): If Home Assistant automatic discovery should be enabled. Defaults to ``True``. - **discovery_retain** (*Optional*, boolean): Whether to retain MQTT discovery messages so that entities are added automatically on Home Assistant restart. Defaults to ``True``. - **discovery_prefix** (*Optional*, string): The prefix to use for Home Assistant’s MQTT discovery. Should not contain trailing slash. Defaults to ``homeassistant``. - **topic_prefix** (*Optional*, string): The prefix used for all MQTT messages. Should not contain trailing slash. Defaults to ````. - **log_topic** (*Optional*, :ref:`mqtt-message`) The topic to send MQTT log messages to. - **birth_message** (*Optional*, :ref:`mqtt-message`): The message to send when a connection to the broker is established. See :ref:`mqtt-last_will_birth` for more information. - **will_message** (*Optional*, :ref:`mqtt-message`): The message to send when the MQTT connection is dropped. See :ref:`mqtt-last_will_birth` for more information. - **shutdown_message** (*Optional*, :ref:`mqtt-message`): The message to send when the node shuts down and the connection is closed cleanly. See :ref:`mqtt-last_will_birth` for more information. - **ssl_fingerprints** (*Optional*, list): Only on ESP8266. A list of SHA1 hashes used for verifying SSL connections. See :ref:`mqtt-ssl_fingerprints` for more information. - **reboot_timeout** (*Optional*, :ref:`time `): The amount of time to wait before rebooting when no MQTT connection exists. Can be disabled by setting this to ``0s``. Defaults to ``5min``. - **keepalive** (*Optional*, :ref:`config-time`): The time to keep the MQTT socket alive, decreasing this can help with overall stability due to more WiFi traffic with more pings. Defaults to 15 seconds. - **on_message** (*Optional*, :ref:`Automation `): An action to be performed when a message on a specific MQTT topic is received. See :ref:`mqtt-on_message`. - **on_json_message** (*Optional*, :ref:`Automation `): An action to be performed when a JSON message on a specific MQTT topic is received. See :ref:`mqtt-on_json_message`. - **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation. .. _mqtt-message: MQTTMessage ----------- With the MQTT Message schema you can tell ESPHome how a specific MQTT message should be sent. It is used in several places like last will and birth messages or MQTT log options. .. code-block:: yaml # Simple: some_option: topic/to/send/to # Disable: some_option: # Advanced: some_option: topic: topic/to/send/to payload: online qos: 0 retain: True Configuration options: - **topic** (**Required**, string): The MQTT topic to publish the message. - **payload** (**Required**, string): The message content. Will be filled by the actual payload with some options, like log_topic. - **qos** (*Optional*, int): The `Quality of Service `__ level of the topic. Defaults to 0. - **retain** (*Optional*, boolean): If the published message should have a retain flag on or not. Defaults to ``True``. The ``log_topic`` has an additional configuration option: - **level** (*Optional*, string): The log level to use for MQTT logs. See :ref:`logger-log_levels` for options. .. _mqtt-using_with_home_assistant: Using with Home Assistant ------------------------- Using ESPHome with Home Assistant is easy, simply setup an MQTT broker (like `mosquitto `__) and point both your Home Assistant installation and ESPHome to that broker. Next, enable discovery in your Home Assistant configuration with the following: .. code-block:: yaml # Example Home Assistant configuration.yaml entry mqtt: broker: ... discovery: True And that should already be it 🎉 All devices defined through ESPHome should show up automatically in the entities section of Home Assistant. When adding new entities, you might run into trouble with old entities still appearing in Home Assistant’s front-end. This is because in order to have Home Assistant “discover” your devices on restart, all discovery MQTT messages need to be retained. Therefore the old entities will also re-appear on every Home Assistant restart even though they’re in ESPHome anymore. To fix this, ESPHome has a simple helper script that purges stale retained messages for you: .. code-block:: bash esphome configuration.yaml clean-mqtt This will remove all retained messages with the topic ``/+/NODE_NAME/#``. If you want to purge on another topic, simply add ``--topic `` to the command. .. _mqtt-defaults: Defaults -------- By default, ESPHome will prefix all messages with your node name or ``topic_prefix`` if you have specified it manually. The client id will automatically be generated by using your node name and adding the MAC address of your device to it. Next, discovery is enabled by default with Home Assistant’s default prefix ``homeassistant``. If you want to prefix all MQTT messages with a different prefix, like ``home/living_room``, you can specify a custom ``topic_prefix`` in the configuration. That way, you can use your existing wildcards like ``home/+/#`` together with ESPHome. All other features of ESPHome (like availability) should still work correctly. .. _mqtt-last_will_birth: Last Will And Birth Messages ---------------------------- ESPHome uses the `last will testament `__ and birth message feature of MQTT to achieve availability reporting for Home Assistant. If the node is not connected to MQTT, Home Assistant will show all its entities as unavailable (a feature 😉). .. figure:: /components/images/mqtt-availability.png :align: center :width: 50.0% By default, ESPHome will send a retained MQTT message to ``/status`` with payload ``online``, and will tell the broker to send a message ``/status`` with payload ``offline`` if the connection drops. You can change these messages by overriding the ``birth_message`` and ``will_message`` with the following options. .. code-block:: yaml mqtt: # ... birth_message: topic: myavailability/topic payload: online will_message: topic: myavailability/topic payload: offline - **birth_message** (*Optional*, :ref:`mqtt-message`) - **will_message** (*Optional*, :ref:`mqtt-message`) If the birth message and last will message have empty topics or topics that are different from each other, availability reporting will be disabled. .. _mqtt-ssl_fingerprints: SSL Fingerprints ---------------- On the ESP8266 you have the option to use SSL connections for MQTT. This feature will get expanded to the ESP32 once the base library, AsyncTCP, supports it. Please note that the SSL feature only checks the SHA1 hash of the SSL certificate to verify the integrity of the connection, so every time the certificate changes, you'll have to update the fingerprints variable. Additionally, SHA1 is known to be partially insecure and with some computing power the fingerprint can be faked. To get this fingerprint, first put the broker and port options in the configuration and then run the ``mqtt-fingerprint`` script of ESPHome to get the certificate: .. code-block:: bash esphome livingroom.yaml mqtt-fingerprint > SHA1 Fingerprint: a502ff13999f8b398ef1834f1123650b3236fc07 > Copy above string into mqtt.ssl_fingerprints section of livingroom.yaml .. code-block:: yaml mqtt: # ... ssl_fingerprints: - a502ff13999f8b398ef1834f1123650b3236fc07 .. _config-mqtt-component: MQTT Component Base Configuration --------------------------------- All components in ESPHome that do some sort of communication through MQTT can have some overrides for specific options. .. code-block:: yaml name: "Component Name" # Optional variables: retain: True discovery: True availability: topic: livingroom/status payload_available: online payload_not_available: offline state_topic: livingroom/custom_state_topic command_topic: livingroom/custom_command_topic Configuration variables: - **name** (**Required**, string): The name to use for the MQTT Component. - **retain** (*Optional*, boolean): If all MQTT state messages should be retained. Defaults to ``True``. - **discovery** (*Optional*, boolean): Manually enable/disable discovery for a component. Defaults to the global default. - **availability** (*Optional*): Manually set what should be sent to Home Assistant for showing entity availability. Default derived from :ref:`global birth/last will message `. - **state_topic** (*Optional*, string): The topic to publish state updates to. Defaults to ``///state``. - **command_topic** (*Optional*, string): The topic to subscribe to for commands from the remote. Defaults to ``///command``. .. warning:: When changing these options and you're using MQTT discovery, you will need to restart Home Assistant. This is because Home Assistant only discovers a device once in every Home Assistant start. .. _mqtt-on_message: ``on_message`` Trigger ---------------------- With this configuration option you can write complex automations whenever an MQTT message on a specific topic is received. To use the message content, use a :ref:`lambda ` template, the message payload is available under the name ``x`` inside that lambda. .. code-block:: yaml mqtt: # ... on_message: topic: my/custom/topic qos: 0 then: - switch.turn_on: some_switch Configuration variables: - **topic** (**Required**, string): The MQTT topic to subscribe to and listen for MQTT messages on. Every time a message with **this exact topic** is received, the automation will trigger. - **qos** (*Optional*, integer): The MQTT Quality of Service to subscribe to the topic with. Defaults to 0. - **payload** (*Optional*, string): Optionally set a payload to match. Only if exactly the payload you specify with this option is received, the automation will be executed. .. note:: You can even specify multiple ``on_message`` triggers by using a YAML list: .. code-block:: yaml mqtt: on_message: - topic: some/topic then: - # ... - topic: some/other/topic then: - # ... .. note:: This action can also be used in :ref:`lambdas `: .. code-block:: cpp App.get_mqtt_client()->subscribe("the/topic", [=](const std::string &payload) { // do something with payload }); .. _mqtt-on_json_message: ``on_json_message`` Trigger --------------------------- With this configuration option you can write complex automations whenever a JSON-encoded MQTT message is received. To use the message content, use a :ref:`lambda ` template, the decoded message payload is available under the name ``x`` inside that lambda. The ``x`` object is of type ``JsonObject`` by the `ArduinoJson `__ library, and you can use all of the methods of that library to access data. Basically, you can access elements by typing ``x["THE_KEY"]`` and save them into local variables. Please note that it's a good idea to check if the key exists in the Json Object by calling ``containsKey`` first as the ESP will crash if an element that does not exist is accessed. .. code-block:: yaml mqtt: # ... on_json_message: topic: the/topic then: - light.turn_on: id: living_room_lights transition_length: !lambda |- int length = 1000; if (x.containsKey("length")) length = x["length"]; return length; brightness: !lambda "return x["bright"];" effect: !lambda |- const char *effect = "None"; if (x.containsKey("effect")) effect = x["effect"]; return effect; Configuration variables: - **topic** (**Required**, string): The MQTT topic to subscribe to and listen for MQTT messages on. Every time a message with **this exact topic** is received, the automation will trigger. - **qos** (*Optional*, integer): The MQTT Quality of Service to subscribe to the topic with. Defaults to 0. .. note:: Due to the way this trigger works internally it is incompatible with certain actions and will trigger a compile failure. For example with the ``delay`` action. .. note:: This action can also be used in :ref:`lambdas `: .. code-block:: cpp App.get_mqtt_client()->subscribe_json("the/topic", [=](JsonObject &root) { // do something with JSON-decoded value root }); .. _mqtt-publish_action: ``mqtt.publish`` Action ----------------------- Publish an MQTT message on a topic using this action in automations. .. code-block:: yaml on_...: then: - mqtt.publish: topic: some/topic payload: "Something happened!" # Templated: - mqtt.publish: topic: !lambda |- if (id(reed_switch).state) return "topic1"; else return "topic2"; payload: !lambda |- return id(reed_switch).state ? "YES" : "NO"; Configuration options: - **topic** (*Required*, string, :ref:`templatable `): The MQTT topic to publish the message. - **payload** (*Required*, string, :ref:`templatable `): The message content. - **qos** (*Optional*, int, :ref:`templatable `): The `Quality of Service `__ level of the topic. Defaults to 0. - **retain** (*Optional*, boolean, :ref:`templatable `): If the published message should have a retain flag on or not. Defaults to ``False``. .. note:: This action can also be written in :ref:`lambdas `: .. code-block:: yaml mqtt: # Give the mqtt component an ID id: mqtt_client .. code-block:: cpp id(mqtt_client).publish("the/topic", "The Payload"); .. _mqtt-publish_json_action: ``mqtt.publish_json`` Action ---------------------------- Publish a JSON-formatted MQTT message on a topic using this action in automations. The JSON message will be constructed using the `ArduinoJson `__ library. In the ``payload`` option you have access to a ``root`` object which will represents the base object of the JSON message. You can assign values to keys by using the ``root["KEY_NAME"] = VALUE;`` syntax as seen below. .. code-block:: yaml on_...: then: - mqtt.publish_json: topic: the/topic payload: |- root["key"] = id(my_sensor).state; root["greeting"] = "Hello World"; # Will produce: # {"key": 42.0, "greeting": "Hello World"} Configuration options: - **topic** (*Required*, string, :ref:`templatable `): The MQTT topic to publish the message. - **payload** (*Required*, :ref:`lambda `): The message content. - **qos** (*Optional*, int): The `Quality of Service `__ level of the topic. Defaults to 0. - **retain** (*Optional*, boolean): If the published message should have a retain flag on or not. Defaults to ``False``. .. note:: This action can also be written in :ref:`lambdas `: .. code-block:: yaml mqtt: # Give the mqtt component an ID id: mqtt_client .. code-block:: cpp id(mqtt_client).publish_json("the/topic", [=](JsonObject &root) { root["something"] = id(my_sensor).state; }); See Also -------- - :apiref:`mqtt/mqtt_client_component.h` - :ghedit:`Edit` .. disqus::