Set up SMS alerts
SMS is a loud, hard-to-miss channel that doesn’t depend on a data connection, making it a good choice for a personal phone contact or a mid-tier in an escalation ladder.
Settings reference
Section titled “Settings reference”| Setting (UI label) | API field (v2) | Type / allowed values | Default | Plan limits | What it does for you |
|---|---|---|---|---|---|
| Contact Type | type |
"sms" |
- | - | |
| Phone number | address |
Phone number in full international format (with country code) | - (required) | - | Where the text is sent |
groupedAlerts, plainText, mimeType, httpHeaders and templates don’t apply to SMS - the app doesn’t
show them for this type, and setting them through the API has no effect on delivery. SMS cannot receive
scheduled reports (email-only, see subscriptions).
Set it up in the app
Section titled “Set it up in the app”- Open Alerts & Contacts and click + Add contact.
- Choose SMS.
- Enter the phone number in full international format (with country code), and give the contact a name.
- Save, then confirm the contact using the code sent to that number. See confirmed vs unconfirmed contacts.
What the message looks like
Section titled “What the message looks like”A short plain-text message: the monitor’s name, what happened (down/up/still-down), and a brief error summary when there is one - no links, no formatting, since SMS has no rich content. See SMS & voice billing for exactly how the message text turns into a segment count and a cost.
Do it with the API or MCP
Section titled “Do it with the API or MCP”POST /contact{ "type": "sms", "address": "+15551234567", "name": "On-call phone" }MCP: create_contact(type="sms", address="+15551234567", name="On-call phone"). Confirm with
send_contact_confirmation / confirm_contact.
What happens next
Section titled “What happens next”HostTracker sends a confirmation code by text immediately. The contact receives nothing real until it’s confirmed. Once confirmed and subscribed, every Down/Up/still-down that reaches it (after its own alert delay and active hours) is a billed SMS - see SMS & voice billing.
Limits and gotchas
Section titled “Limits and gotchas”- SMS draws from your SMS credit balance and is counted by segment - a message using non-Latin characters or emoji costs more segments than plain text. See how SMS & voice billing works.
- Some countries and carriers restrict delivery from certain senders - if a confirmation code doesn’t arrive, double-check the number format before assuming it’s a delivery problem.
- Pair SMS with active hours if you don’t want text messages outside working hours.
- Changing a confirmed contact’s address resets it back to unconfirmed - a new code goes to the new number.