Send domain alerts to Slack

Email is fine for one person. A team wants the alert where it already talks. Domain Sentinel can post every alert to a Slack channel through an incoming webhook: no bot to write, no app to publish, one URL to paste. This guide takes about five minutes.

What you get

Each alert becomes a Slack message with the domain, a one-line summary, the list of changes when there are any, and a link back to the domain in Domain Sentinel. Expiration reminders, availability and registration alerts, registry and DNS changes, certificate expiry and the periodic report all use the same channel, and you choose which ones the channel receives.

Step 1: create the incoming webhook in Slack

1. Open api.slack.com/apps and click Create New App, then From scratch.
2. Give it a name (for example "Domain Sentinel") and pick your workspace.
3. In the app's menu, open Incoming Webhooks and switch Activate Incoming Webhooks on.
4. Click Add New Webhook to Workspace, choose the channel that should receive the alerts, and allow.
5. Copy the webhook URL. It starts with https://hooks.slack.com/services/.

The URL is a secret: anyone who has it can post in that channel. Treat it like a password.

The two Slack paths, and which one to take

Slack offers webhook URLs in two places, and they both work with Domain Sentinel:

• A Slack app with the Incoming Webhooks feature, the path above. This is the current method, with no warning.
• The "Incoming WebHooks" custom integration in the Slack app directory (Slack, Apps, search "Incoming WebHooks"). Slack labels it a legacy integration and shows a notice saying it may be deprecated and removed. It still produces the same kind of URL, and an existing one keeps working, but do not create new ones there: build the app instead.

Slack's Workflow Builder can also expose a webhook trigger, but it expects variables you define yourself rather than a message. Domain Sentinel does not target it.

Step 2: add the endpoint in Domain Sentinel

1. In the dashboard, open Notifications, Settings, then Webhooks (or go to Webhooks directly).
2. Click Add a webhook, give it a label ("#ops" works well), paste the Slack URL and pick the Slack format.
3. Choose the filters. Nothing checked means every alert type. The scope lets you send only some domains, either by monitoring group or picked one by one, which is how you get one channel per client or per team.
4. Save, then click Send test on the row. A test message should appear in the channel within a second or two.

The Slack format sends a message shaped for Slack and no signature headers, because Slack does not check any. If you need the raw JSON payload instead, for Zapier or your own server, use the JSON format.

What the message looks like

The title is a link to the domain's page. Below it, the summary, then a bullet per change for DNS and registry alerts ("A example.com: 1.1.1.1 → 2.2.2.2"), and a small context line with the alert type and the domain. On a phone, the notification preview shows the title and the summary.

Tips

• One webhook per audience. A "#clients" channel scoped to the Clients group, a "#infra" channel scoped to the Infra group. Domains added to a group later are covered without touching the webhook.
• Turn the email off if the channel is enough. In the notification settings, the Email switch stops the alert emails; the alerts stay in the app and keep going to Slack. The page warns you if no webhook is active.
• Mattermost and Rocket.Chat accept the Slack format as is. Paste their incoming-webhook URL and pick Slack.

If it does not work

• "HTTP 400" on the test: the URL is not a Slack incoming webhook, or the format is set to JSON. Switch the format to Slack.
• "HTTP 404": the webhook was deleted in Slack. Create a new one and update the URL.
• The endpoint shows "Off after failures": ten deliveries in a row failed, so Domain Sentinel stopped trying. Fix the receiver, then click Enable; the counter starts again from zero.

For Discord, the setup is the same idea with a channel webhook: see Send domain alerts to Discord. For what the alerts themselves cover, see Domain monitoring alerts.