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Shelly Pro 3EM MQTT scripts

A Shelly Pro 3EM does not provide a 1–2 second MQTT telemetry cadence natively. The scripts on this page run on the device and publish telemetry every second. Choose the section that matches the Shelly's configured metering profile.

Three single-phase meters profile

Scope

Use this script with a Shelly Pro 3EM configured in the three single-phase meters profile. It reads EM1.GetStatus for channels 0, 1 and 2 and exposes each channel as a separate clamp.

Requirements

  • MQTT enabled and connected on the Shelly device.
  • Home Assistant connected to the same MQTT broker.
  • MQTT Discovery enabled in Home Assistant (the default prefix is homeassistant).

Installation

  1. Open the Shelly web interface and go to Scripts.
  2. Create a new script and paste the code below.
  3. Save the script, then enable and run it.
  4. Select the discovered grid-power sensor when configuring Omnibattery's main sensor.

The script publishes state to shellypro3em/<device-id>/state and availability to shellypro3em/<device-id>/availability. Discovery messages are retained by the MQTT broker, while state is published once per second.

Script

// Shelly Pro 3EM in three single-phase meters profile
// MQTT telemetry + Home Assistant MQTT Discovery.
//
// Publishes every second:
// - Active power, voltage, current, and power factor per clamp
// - Total active power calculated from all three clamps
//
// Requirements:
// - MQTT enabled and connected on the Shelly device
// - Home Assistant connected to the same MQTT broker
// - MQTT Discovery enabled in Home Assistant (default prefix: homeassistant)

let DISCOVERY_PREFIX = "homeassistant";
let STATE_INTERVAL_MS = 1000;
let STATE_EXPIRE_AFTER_S = 5;

let dev = Shelly.getDeviceInfo();
let DEVICE_ID = dev.id || "shellypro3em";
let DEVICE_NAME = dev.name || "Shelly Pro 3EM";

let BASE_TOPIC = "shellypro3em/" + DEVICE_ID;
let STATE_TOPIC = BASE_TOPIC + "/state";
let AVAILABILITY_TOPIC = BASE_TOPIC + "/availability";

let lastAvailability = null;
let publishing = false;

function haConfigTopic(objectId) {
  return DISCOVERY_PREFIX + "/sensor/" + DEVICE_ID + "_" + objectId + "/config";
}

function setAvailability(online) {
  if (lastAvailability === online) return;

  lastAvailability = online;
  MQTT.publish(
    AVAILABILITY_TOPIC,
    online ? "online" : "offline",
    0,
    true
  );
}

function publishDiscoverySensor(
  objectId,
  name,
  unit,
  deviceClass,
  stateClass,
  valueTemplate
) {
  let payload = {
    name: name,
    unique_id: DEVICE_ID + "_" + objectId,
    object_id: DEVICE_ID + "_" + objectId,

    state_topic: STATE_TOPIC,
    value_template: valueTemplate,
    expire_after: STATE_EXPIRE_AFTER_S,

    availability_topic: AVAILABILITY_TOPIC,
    payload_available: "online",
    payload_not_available: "offline",

    unit_of_measurement: unit,
    device_class: deviceClass,
    state_class: stateClass,
    force_update: false,

    device: {
      identifiers: [DEVICE_ID],
      name: DEVICE_NAME,
      manufacturer: "Shelly",
      model: "Shelly Pro 3EM",
      sw_version: dev.fw_id || ""
    }
  };

  // Retained: Home Assistant can recreate the entities after a restart.
  MQTT.publish(haConfigTopic(objectId), JSON.stringify(payload), 0, true);
}

function publishDiscovery() {
  // Total active power
  publishDiscoverySensor(
    "total_active_power",
    "Total Active Power",
    "W",
    "power",
    "measurement",
    "{{ value_json.total_act_power | float(0) }}"
  );

  // Clamp 1
  publishDiscoverySensor(
    "clamp_1_active_power",
    "Clamp 1 Active Power",
    "W", "power", "measurement",
    "{{ value_json.clamp_1.act_power | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_1_voltage",
    "Clamp 1 Voltage",
    "V", "voltage", "measurement",
    "{{ value_json.clamp_1.voltage | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_1_current",
    "Clamp 1 Current",
    "A", "current", "measurement",
    "{{ value_json.clamp_1.current | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_1_power_factor",
    "Clamp 1 Power Factor",
    "", "power_factor", "measurement",
    "{{ value_json.clamp_1.pf | float(0) }}"
  );

  // Clamp 2
  publishDiscoverySensor(
    "clamp_2_active_power",
    "Clamp 2 Active Power",
    "W", "power", "measurement",
    "{{ value_json.clamp_2.act_power | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_2_voltage",
    "Clamp 2 Voltage",
    "V", "voltage", "measurement",
    "{{ value_json.clamp_2.voltage | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_2_current",
    "Clamp 2 Current",
    "A", "current", "measurement",
    "{{ value_json.clamp_2.current | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_2_power_factor",
    "Clamp 2 Power Factor",
    "", "power_factor", "measurement",
    "{{ value_json.clamp_2.pf | float(0) }}"
  );

  // Clamp 3
  publishDiscoverySensor(
    "clamp_3_active_power",
    "Clamp 3 Active Power",
    "W", "power", "measurement",
    "{{ value_json.clamp_3.act_power | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_3_voltage",
    "Clamp 3 Voltage",
    "V", "voltage", "measurement",
    "{{ value_json.clamp_3.voltage | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_3_current",
    "Clamp 3 Current",
    "A", "current", "measurement",
    "{{ value_json.clamp_3.current | float(0) }}"
  );
  publishDiscoverySensor(
    "clamp_3_power_factor",
    "Clamp 3 Power Factor",
    "", "power_factor", "measurement",
    "{{ value_json.clamp_3.pf | float(0) }}"
  );
}

function publishState() {
  // Prevent overlapping asynchronous requests.
  if (publishing) return;
  publishing = true;

  Shelly.call("EM1.GetStatus", { id: 0 }, function (c1, err1, msg1) {
    if (err1 !== 0) {
      print("EM1:0 error:", err1, msg1);
      setAvailability(false);
      publishing = false;
      return;
    }

    Shelly.call("EM1.GetStatus", { id: 1 }, function (c2, err2, msg2) {
      if (err2 !== 0) {
        print("EM1:1 error:", err2, msg2);
        setAvailability(false);
        publishing = false;
        return;
      }

      Shelly.call("EM1.GetStatus", { id: 2 }, function (c3, err3, msg3) {
        if (err3 !== 0) {
          print("EM1:2 error:", err3, msg3);
          setAvailability(false);
          publishing = false;
          return;
        }

        let p1 = c1.act_power || 0;
        let p2 = c2.act_power || 0;
        let p3 = c3.act_power || 0;

        let payload = {
          total_act_power: p1 + p2 + p3,

          clamp_1: {
            act_power: c1.act_power,
            aprt_power: c1.aprt_power,
            current: c1.current,
            voltage: c1.voltage,
            pf: c1.pf,
            freq: c1.freq
          },

          clamp_2: {
            act_power: c2.act_power,
            aprt_power: c2.aprt_power,
            current: c2.current,
            voltage: c2.voltage,
            pf: c2.pf,
            freq: c2.freq
          },

          clamp_3: {
            act_power: c3.act_power,
            aprt_power: c3.aprt_power,
            current: c3.current,
            voltage: c3.voltage,
            pf: c3.pf,
            freq: c3.freq
          }
        };

        setAvailability(true);
        MQTT.publish(STATE_TOPIC, JSON.stringify(payload), 0, false);
        publishing = false;
      });
    });
  });
}

// Publish discovery configuration once on each script start.
// Config messages are retained by the MQTT broker.
publishDiscovery();

// Publish immediately, then every second.
publishState();
Timer.set(STATE_INTERVAL_MS, true, publishState);

Three-phase profile

Scope

Use this script with a Shelly Pro 3EM configured with the triphase profile. It reads EM.GetStatus with id: 0 and publishes the three phases as phase_a, phase_b and phase_c. Run only one of the two profile scripts at a time.

Requirements

  • The Shelly Pro 3EM must use the triphase metering profile.
  • MQTT enabled and connected on the Shelly device.
  • Home Assistant connected to the same MQTT broker.
  • MQTT Discovery enabled in Home Assistant (the default prefix is homeassistant).

Installation

  1. Open the Shelly web interface and go to Scripts.
  2. Create a new script, or replace the script for the other metering profile.
  3. Paste the code below, save it, then enable and run it.
  4. Select the discovered grid-power sensor when configuring Omnibattery's main sensor.

This script uses the same state and availability topics as the single-phase-profile script, so do not run both scripts simultaneously for the same device.

Script

// Shelly Pro 3EM — perfil trifásico
// MQTT telemetry + Home Assistant MQTT Discovery.
//
// Requiere:
// - Perfil del Shelly: "triphase"
// - MQTT habilitado y conectado
// - MQTT Discovery habilitado en Home Assistant

let DISCOVERY_PREFIX = "homeassistant";
let STATE_INTERVAL_MS = 1000;
let STATE_EXPIRE_AFTER_S = 5;

let dev = Shelly.getDeviceInfo();
let DEVICE_ID = dev.id || "shellypro3em";
let DEVICE_NAME = dev.name || "Shelly Pro 3EM";

let BASE_TOPIC = "shellypro3em/" + DEVICE_ID;
let STATE_TOPIC = BASE_TOPIC + "/state";
let AVAILABILITY_TOPIC = BASE_TOPIC + "/availability";

let lastAvailability = null;
let publishing = false;

function haConfigTopic(objectId) {
  return DISCOVERY_PREFIX + "/sensor/" + DEVICE_ID + "_" + objectId + "/config";
}

function setAvailability(online) {
  if (lastAvailability === online) return;

  lastAvailability = online;
  MQTT.publish(
    AVAILABILITY_TOPIC,
    online ? "online" : "offline",
    0,
    true
  );
}

function publishDiscoverySensor(
  objectId,
  name,
  unit,
  deviceClass,
  stateClass,
  valueTemplate
) {
  let payload = {
    name: name,
    unique_id: DEVICE_ID + "_" + objectId,
    object_id: DEVICE_ID + "_" + objectId,

    state_topic: STATE_TOPIC,
    value_template: valueTemplate,
    expire_after: STATE_EXPIRE_AFTER_S,

    availability_topic: AVAILABILITY_TOPIC,
    payload_available: "online",
    payload_not_available: "offline",

    unit_of_measurement: unit,
    device_class: deviceClass,
    state_class: stateClass,

    device: {
      identifiers: [DEVICE_ID],
      name: DEVICE_NAME,
      manufacturer: "Shelly",
      model: "Shelly Pro 3EM",
      sw_version: dev.fw_id || ""
    }
  };

  MQTT.publish(haConfigTopic(objectId), JSON.stringify(payload), 0, true);
}

function publishPhaseDiscovery(phase, label) {
  publishDiscoverySensor(
    "phase_" + phase + "_active_power",
    "Fase " + label + " Potencia activa",
    "W", "power", "measurement",
    "{{ value_json.phase_" + phase + ".act_power | float(0) }}"
  );

  publishDiscoverySensor(
    "phase_" + phase + "_voltage",
    "Fase " + label + " Voltaje",
    "V", "voltage", "measurement",
    "{{ value_json.phase_" + phase + ".voltage | float(0) }}"
  );

  publishDiscoverySensor(
    "phase_" + phase + "_current",
    "Fase " + label + " Corriente",
    "A", "current", "measurement",
    "{{ value_json.phase_" + phase + ".current | float(0) }}"
  );

  publishDiscoverySensor(
    "phase_" + phase + "_power_factor",
    "Fase " + label + " Factor de potencia",
    "", "power_factor", "measurement",
    "{{ value_json.phase_" + phase + ".pf | float(0) }}"
  );
}

function publishDiscovery() {
  publishDiscoverySensor(
    "total_active_power",
    "Potencia activa total",
    "W", "power", "measurement",
    "{{ value_json.total_act_power | float(0) }}"
  );

  publishDiscoverySensor(
    "total_current",
    "Corriente total",
    "A", "current", "measurement",
    "{{ value_json.total_current | float(0) }}"
  );

  publishPhaseDiscovery("a", "A");
  publishPhaseDiscovery("b", "B");
  publishPhaseDiscovery("c", "C");
}

function phasePayload(status, phase) {
  return {
    act_power: status[phase + "_act_power"],
    aprt_power: status[phase + "_aprt_power"],
    current: status[phase + "_current"],
    voltage: status[phase + "_voltage"],
    pf: status[phase + "_pf"],
    freq: status[phase + "_freq"]
  };
}

function publishState() {
  if (publishing) return;
  publishing = true;

  Shelly.call("EM.GetStatus", { id: 0 }, function (status, err, msg) {
    publishing = false;

    if (err !== 0) {
      print("EM:0 error:", err, msg);
      setAvailability(false);
      return;
    }

    let totalPower = status.total_act_power;
    if (totalPower === null || typeof totalPower === "undefined") {
      totalPower =
        (status.a_act_power || 0) +
        (status.b_act_power || 0) +
        (status.c_act_power || 0);
    }

    let payload = {
      total_act_power: totalPower,
      total_aprt_power: status.total_aprt_power,
      total_current: status.total_current,
      neutral_current: status.n_current,

      phase_a: phasePayload(status, "a"),
      phase_b: phasePayload(status, "b"),
      phase_c: phasePayload(status, "c")
    };

    setAvailability(true);
    MQTT.publish(STATE_TOPIC, JSON.stringify(payload), 0, false);
  });
}

publishDiscovery();
publishState();
Timer.set(STATE_INTERVAL_MS, true, publishState);