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Set up Slack alerts

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Slack alerts use a Slack incoming webhook, which is a URL that posts a message directly into a chosen channel in your workspace. Under the hood a Slack contact is an http contact - HostTracker recognizes it automatically from the webhook URL itself, with no separate gateway field to set.

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 "http" - - Slack is stored as a plain http contact
Webhook URL address A https://hooks.slack.com/... URL - (required) - Where the message posts; HostTracker detects Slack automatically from this prefix
Group events groupedAlerts boolean false - Combine simultaneous alerts into one message - see grouped alerts

You can also set gateway: "Slack" explicitly (matching a legacy back-compat shape), but it isn’t required - the hooks.slack.com address prefix is checked unconditionally, ahead of every other gateway’s rule.

Set it up in the app

Section titled “Set it up in the app”
  1. In Slack, create an incoming webhook for the channel you want alerts in (from your workspace’s App Directory, search for “Incoming Webhooks” and add one, or use an existing Slack app with that permission). Copy the webhook URL Slack gives you.
  2. In HostTracker, open Contacts and click Add contact.
  3. Choose Slack (or add it as a webhook contact - a hooks.slack.com URL is recognized automatically).
  4. Paste the webhook URL and give the contact a name.
  5. Save.

What the message looks like

Section titled “What the message looks like”

Slack alerts render as rich formatted cards, not plain text - including for certificate, domain-expiry and blacklist alerts, with the monitor name, status, and relevant details laid out in Slack’s block format rather than a raw text blob.

Do it with the API or MCP

Section titled “Do it with the API or MCP”
POST /contact
{ "type": "http", "address": "https://hooks.slack.com/services/...", "name": "Team Slack" }

MCP: creating a Slack contact isn’t covered by the create_contact tool (it only creates email/sms/ voiceCall/webPush) - use api_request with the body above.

What happens next

Section titled “What happens next”

An http contact is born confirmed - there’s no code to verify, since posting a real message to the webhook is the proof it works. Send a test alert to confirm delivery before relying on it.

Limits and gotchas

Section titled “Limits and gotchas”
  • Alerts always land in whichever channel the webhook is bound to in Slack. To alert a different channel, create a new incoming webhook there and add it as a separate contact.
  • Grouping is off by default. Turn on the contact’s Group events toggle to combine simultaneous alerts to the same webhook into one message instead of flooding the channel.
  • If Slack ever revokes or regenerates the webhook URL, HostTracker has no way to know - a test alert is the fastest way to notice.
  • Being a recognized gateway also means Slack can receive certificate-expiry, domain-expiry, DNSBL blacklist and Web Risk notices - a plain unrecognized webhook contact cannot (see Webhook).
Section titled “Related”