Send Home Assistant alerts to WhatsApp

A rest_command and one automation. No phone number of your own, no WhatsApp Business account, and nothing charged per contact.

The usual answer here is CallMeBot, and it is free and perfectly good at what it does. What it does is written on its own page: "The Free API is only for personal use", and the list of things it does not do opens with sending to other people. So the moment the alert needs to reach somebody else in the house, or a colleague, you are outside it — and the other routes are a self-hosted bridge holding your personal WhatsApp number open as a linked device, or Telegram instead.

This is a rest_command to an endpoint with its own registered number and its own approved template. It messages your own verified people — you, and whoever else in the house has verified a phone — which is all a home automation needs.

1. Make a key

In the Jabee dashboard, go to Management then Approvals and create an API key. It starts jak_. Copy it now; it is not shown again.

Whoever is going to be messaged needs a verified phone, which they get by tapping a link in the dashboard and sending one message. Until somebody has done that there is nobody to deliver to.

2. Add the rest_command

The key goes in secrets.yaml, as the whole header value including the word Bearer:

# secrets.yaml
jabee_authorization: "Bearer jak_your_key_here"

Then configuration.yaml:

rest_command:
  jabee_alert:
    url: https://api.jabee.ai/api/v1/alerts
    method: POST
    content_type: "application/json"
    headers:
      authorization: !secret jabee_authorization
    payload: >
      {{ {'title': title, 'body': body | default('')} | to_json }}

The | to_json is the part worth copying exactly. Building that JSON by hand works until a sensor name has an apostrophe or a template renders a newline, and then it fails in a way that is genuinely annoying to debug. Letting Home Assistant serialise a dictionary makes that impossible.

Restart Home Assistant, then try it from Developer tools → Actions: pick rest_command.jabee_alert and give it a title.

3. Call it from an automation

automation:
  - alias: Tell me if the freezer is warming up
    triggers:
      - trigger: numeric_state
        entity_id: sensor.freezer_temperature
        above: -12
        for: "00:15:00"
    actions:
      - action: rest_command.jabee_alert
        data:
          title: "Freezer is at {{ states('sensor.freezer_temperature') }}°C"
          body: "Above -12 for fifteen minutes. Door left open?"

That is the 2024.10 spelling (triggers:, actions:, action: for the call). The older trigger: / action: / service: form still works and was never deprecated, so an older configuration does not need rewriting.

The for: is not optional in spirit. A numeric sensor crossing a threshold will cross it repeatedly, and without a duration you get a message every time it wobbles.

What this is good for, and what it is not

Good for the handful of things that genuinely need to reach a phone that has notifications silenced: water on the floor, a freezer warming, the alarm, a camera seeing somebody at 3am, the boiler out in winter. WhatsApp gets through where a companion-app notification does not.

Not good for the ordinary stream — someone arrived home, washing finished, a light left on. Those belong in the companion app, which is free and unlimited. 500 a month sounds generous until a presence automation discovers it.

An honest comparison: for high-volume home notifications, a Telegram bot or ntfy costs nothing and has no allowance at all. The reason to put a few things on WhatsApp is that it is the app people actually have open.

Which phone it reaches

One per household, and it is yours: the account owner's verified number by default, or another handset you point alerts at in the dashboard, under Where alerts go. That phone verifies itself by sending one message to the Jabee number, carrying a code from the dashboard.

Anyone you send to has to have verified their phone with us first — a link in the dashboard and one message. There is no way to message a number that has not done that, which is deliberate: a shared number texting people who never asked for it is exactly what gets numbers banned.

One honest caveat: this is not a local integration

It is an HTTPS call to a hosted API, so it needs the internet and it is one more thing that can be down. For a house that is otherwise local-only, that is a real consideration — and the automation should not depend on the message succeeding. rest_command failures appear in the log; they do not stop the rest of the actions.

What it costs

$29 a month for 500 alerts and approvals together, then 3 cents each. The first three are free, so you can wire this up and watch a message arrive before paying for anything. No per-seat charge.

Charged per account, not per contact and not per person messaged, which is the comparison worth making against the per-recipient services this corner of the world usually reaches for. If it is only ever your own phone, note honestly that CallMeBot and ntfy do that for nothing — the whole comparison is here, including the cases where this page is the wrong answer.

Questions