IoT Message

Help

Guides

Alerts

Get a text when a reading goes over a limit
  1. Open Triggers and press New trigger.
  2. Under the ready-made triggers, choose A reading above a number.
  3. Under Conditions, set Field to the reading, such as data.temp, and Value to your limit.
  4. Under What it does, choose a Template, or keep the standard alert.
  5. Under Send to, choose who gets it, then press Save trigger.
  6. Open the trigger's Test tab to see which of your recent events it would have matched.
Know when a device goes offlineNeeds your Hologram API key.
  1. Open Settings, Device platform, Requests to Hologram, and turn on Read data sessions.
  2. Open Triggers, New trigger, and choose A device goes offline. For a device that sleeps between sessions, choose A device not heard from in two hours.
  3. Choose who gets it and press Save trigger. Tick Back online in its event types to hear when it returns.
Only alert at certain times
  1. Open the trigger, tab Events.
  2. Under When it runs, choose Only on these days and times.
  3. Pick the days and hours, or press one of the Examples, such as After hours on workdays.
  4. Press Save events. Times are in your account's time zone.
Send alerts to Slack, Teams or your serverOn paid plans.
  1. Open Settings, Webhook destinations, and press Add destination.
  2. Press Send a test to check it arrives.
  3. In each trigger, under What it does, tick the destination under Webhook destinations.

Recipients

Choose who gets alerts for each device
  1. Open Recipients and press Add recipient.
  2. Enter their name and mobile number, or an email address.
  3. Under Gets alerts for, choose the Devices or Tags they cover, then press Add recipient.
  4. In each trigger, under Send to, choose Everyone who gets alerts for the device that sent the event.
Let people sign themselves up
  1. Open Recipients, tab Signup link, and copy the link.
  2. Share it, on a label on the device or in an email.
  3. Each person who signs up waits on Recipients. Press Approve; nothing reaches them before that.

Devices and SIMs

Text a device from your phoneOn plans that include relay, with your Hologram API key.
  1. Open Relay. Its Quick start checks what relay needs, one step at a time.
  2. Under Add a number, add your mobile number and confirm it with the code we text you.
  3. Text our number from your phone, as the Quick start shows. The device gets your text, and its reply comes back to you.
Pause a SIM put into other hardwareOn paid plans, with your Hologram API key.
  1. Open Settings, Device platform, Requests to Hologram, and turn on Pause or resume a SIM.
  2. Open Triggers, New trigger, and choose Pause a SIM put into hardware not on its list.
  3. Press Save trigger. Each device's page, tab Protection, shows its IMEI allow list.
Cap a SIM's data useOn paid plans, with your Hologram API key.
  1. Open Settings, Device platform, Requests to Hologram, and turn on Read data use and Pause or resume a SIM.
  2. Open Devices, the device, tab Protection.
  3. Under Data budget, enter the Megabytes, choose Each day, week or month, and press Save budget.
  4. The SIM pauses when it reaches the budget, and resumes when the next period starts.

Hologram: webhook or API key

A webhook is an alert you set up in Hologram that sends each matching event to your IoT Message address. Your API key lets IoT Message read from your Hologram account, about once a minute. The table shows what each one gives you.

Part of IoT MessageWebhook onlyWith your API key
Alerts on Hologram's own alerts Yes One Hologram alert for each: data limit, data warning, first IMEI, hardware change, SMS and API responses. Some Hardware changes and SMS also arrive with your device messages. Data limit, data warning, first IMEI and API responses need a webhook.
Alerts on data your devices send to the Hologram cloud No Hologram sends no webhook for data a device sends to its cloud. Yes Read about once a minute.
Triggers, templates, recipients, and alerts by text and email Yes Yes
Your devices on the Devices page Yes A device appears when it sends its first event. Yes The devices in each organization you read are listed from Hologram when you connect and every 6 hours. In an organization with more than 100 devices, a device appears when it sends its first event, or when you add it by its Hologram device ID.
Recipients signing up for a device on the public signup page No The signup page finds an account only by a device its API key has confirmed. Yes For devices your key has confirmed are yours.
Hologram organization in trigger conditions No A webhook does not say which organization a device is in. Yes
Online and offline alerts, and data budgets No Both read your devices' data sessions and data use with your API key. Yes Once you turn on "Read data sessions", and for budgets "Read data use", under Settings, Device platform.
Pausing a device's SIM from a trigger No Pausing a SIM uses your API key. Yes On paid plans, once you turn on "Pause or resume a SIM" under Settings, Device platform.
Texting a device from a phone (Relay) No Your key confirms the device is yours, and gives the SIM's own number for SMS over the cellular network. Yes By SMS through Hologram Cloud, or by TCP or UDP to a port, once you turn on "Send a message to a device", or by SMS from our number to the SIM's own number as Hologram reports it.
Catching up after an interruption No An alert Hologram sent while IoT Message could not receive it is not sent again. Yes If IoT Message is unexpectedly down or in planned maintenance, or Hologram has a problem, device messages sent in the meantime are read once both are back, and alert under each trigger's setting for late alerts.

Hover over or tap the question mark beside an answer for more.

What IoT Message asks Hologram with your key

  • Which Hologram user the key belongs to, when you connect it and once a day.
  • Your organizations, when you connect and once a day.
  • The devices in each organization, when you connect and every 6 hours, for an organization with 100 devices or fewer.
  • Your device tags' names, once a day and when an event names a tag IoT Message does not know yet.
  • A device by its ID, when you add it or press Get the IMEI from Hologram on its page, and about once a week after that for a device that sends no device message.
  • Your devices' messages, about once a minute.
  • Your devices' data sessions, about every five minutes, only after you turn on Read data sessions.
  • A device's data use, about every ten minutes for a device with a data budget, only after you turn on Read data use.
  • Pause or resume a SIM, only after you turn it on. IoT Message never asks Hologram to deactivate a SIM.
  • Refresh a SIM's network connection, only after you turn it on: a #refresh text from an allowed number.
  • Send a message to a device, only after you turn it on: a text a number on your Relay list sent us.

Under Settings, Device platform, Requests to Hologram, you can see how many of each were sent in the last 30 days, and turn any of them off.

Webhooks from another platform

A platform other than Hologram sends events to its own IoT Message address with a webhook: an HTTP POST whose body is one JSON object. Choose "Another platform" under Settings, Device platform, and we turn on the address for your account after a review; we email you when it is ready.

Address and credential
Both are on Settings, Device platform, Webhook endpoints. Send the credential in the Authorization header as Bearer and the secret.
device_id
The device's ID, a whole number. Without one, the event is kept but no device is added to Devices.
device_name
The device's name, up to 200 characters. Optional.
tags
A list of words, such as ["north", "freezers"]. Optional.
time or timestamp
When it happened, in ISO 8601, such as 2026-10-16T14:05:00Z; without a time zone, UTC. Optional: without it, the time it arrived.
Everything else
The whole object reaches your triggers, so a trigger can test any value in it, such as data.temp. The event shows as type "From another platform".

Want IoT Message to integrate with your platform, the way it does with Hologram? Say which one under Settings, Device platform.

WhatsApp

WhatsApp is an add-on to a paid plan, by request, with a waitlist. We review each request.

  1. On the Plan page, under WhatsApp, enter about how many WhatsApp messages a month you expect, the countries your recipients are in, and what the alerts are for, and press Ask for WhatsApp.
  2. We review it and email you: the monthly allowance, the countries, and the price for them.
  3. Press Add WhatsApp on the Plan page. It is billed with your plan.
  4. On each recipient who should get them, tick Also send alerts by WhatsApp, at their mobile number or a WhatsApp number of its own, and choose their language.
  5. The recipient joins: they scan the QR code on their page in Recipients, or open its link, and send the message it writes in WhatsApp. Their WhatsApp alerts start then.

Alerts by WhatsApp use your template's wording as WhatsApp approved it, in the recipient's language. Replying STOP on WhatsApp stops only the WhatsApp alerts. A verified number on your Relay list, in a country allowed for your account, can also text your devices from WhatsApp, and is answered there.

Questions

What do I need to set up a webhook?
Under Settings, Device platform, Webhook endpoints, you get the address, the credential to put in Hologram's custom header, and the payload to paste into Hologram for each alert type. For another platform, see Webhooks from another platform.
Can I start with a webhook and connect my key later?
Yes. Devices that already sent events stay on your Devices page, and device messages are read from the moment you connect the key.
Can I use both?
Yes. A message that arrives both ways is two events. A trigger with a cooldown sends one alert for the two.
Does IoT Message change anything in my Hologram account?
Only what you turn on: "Pause or resume a SIM" lets a trigger, a data budget or an allowed Relay number pause and resume a SIM, and "Refresh a SIM's network connection" lets an allowed number refresh one. Every other request only reads.
Something else?
Write to us, or use Support in your dashboard.