SMS reaches people who are away from a screen. Because every message costs money, Hermetry sends SMS only where you name phone numbers explicitly, and throttles repeats.
What sends SMS
| Sender | SMS? |
|---|---|
A flow’s Notify block with recipient rows of kind phone | Yes |
| Alarm rules | No: they name members, roles and e-mail addresses. Use a flow to text an alarm (below). |
| Rules-card Tell people | No: it names roles (and, through the API, users and teams). |
| Members and roles in any sender | No: a member’s phone number is not used for notifications. |
Sign-in codes by SMS, where your organisation uses them, are sent by the sign-in itself, not by these settings.
Set up SMS
An administrator opens Settings > SMS (“SMS provider configuration”):
| Field | Meaning |
|---|---|
| Enable SMS Notifications | Turns SMS on or off for the organisation. Off: no SMS is sent, not even for critical alarms. |
| Provider | The SMS provider, with its account fields (account id, token, sender number or name). |
| SMS Providers | More providers, installed and configured as plugins from the marketplace. |
Changing the settings needs Change SMS settings (Admin by default). If the chosen provider has no credentials, Hermetry uses the first provider configured for your organisation.
Phone numbers
- Write numbers in international form, for example
+905551112233or+4915112345678. - A number that does not parse is counted as invalid in the block’s result and skipped; the other recipients still get the message.
- A number that has opted out (by replying STOP where your provider passes replies back) is not sent to until it opts in again (START).
Texting an alarm
Every alarm change also enters the flows of the IoT host as a message of type alarm, with the alarm in msg.payload. A flow that listens for these messages can keep the ones you care about (for example new CRITICAL alarms) and pass them to a Notify block with a phone row such as +905551112233, a title like {{ msg.payload.title }} and channels set to ["sms"].
See Alarm, command and notify blocks and Flow cookbook.
Limits and throttles
| Rule | Effect |
|---|---|
| Per number | Further messages to the same number within 60 seconds are dropped. |
| Notify cooldown | The Notify block sends the same reason to the same recipient once per cooldown (10 minutes unless your plan sets another); the next message carries “(+n)” for the ones held back. |
| Quiet hours | SMS is held back during the organisation’s quiet hours, in the recipient’s time zone, unless the notification is critical. A number-only recipient has no time zone; UTC is used. |
| Monthly quota | Each SMS counts toward your plan’s SMS quota (usage counter smsSends). |
Quota
When the monthly SMS quota is spent, or the plan does not include SMS, a flow’s Notify block leaves SMS out, lists it under quota in its result (“the monthly SMS quota is spent” or “the plan has no SMS access”) and still uses the other channels. Only when every channel it would use is out of quota does the block end with the error limit. See Usage and quotas.
What the message contains
The SMS body is the notification’s text (its plain-text form for HTML notifications). Keep alarm texts short: the provider may split or truncate long messages.
Troubleshooting
| Symptom | Check |
|---|---|
| No SMS at all | Enable SMS Notifications is on; a provider is configured; your plan includes SMS; the quota is not spent. |
| One number gets nothing | The number is in international form; it has not opted out; quiet hours; the 60-second per-number throttle. |
| Alarm SMS never sent | Alarm rules do not send SMS; add a flow with a phone recipient. |
| Every other message missing | The cooldown holds repeats of the same reason; set the block’s reason setting to group them as you want. |
The delivery log records each SMS attempt with the provider’s answer. See The notification log.