Slack & Mattermost

Coolify's Slack notification channel accepts a Slack incoming webhook URL. Mattermost incoming webhooks use a compatible message format, so you configure Mattermost on the same Coolify page.

Configure a provider

Choose the provider that should receive Coolify notifications.

Create an incoming webhook for the Slack channel that should receive notifications.

Create a Slack app

Open the Slack API apps page.
Select Create New App > From scratch.
Enter a name such as Coolify Notifications and select the workspace that owns the destination channel.
Select Create App.

You need permission to install or authorize apps in the workspace. If approval is required, ask a workspace administrator to complete it.

Create the incoming webhook

Open Incoming Webhooks in the app settings.
Turn on Activate Incoming Webhooks.
Select Add New Webhook to Workspace.
Choose the channel that should receive Coolify notifications and authorize the app.
Copy the webhook URL shown under Webhook URLs for Your Workspace.

Add the webhook to Coolify

Open Notifications > Slack, paste the URL into Webhook, and select Save. Then turn on Enabled.

Protect the webhook URL

The webhook URL authorizes posts to its destination channel. Store it as a secret and replace it in the provider and Coolify if it is exposed.

Choose events and verify delivery

Under Notification Settings, select the events to send through this channel. See Notification events for each trigger.

Select Send Test Notification and confirm that the message arrives in the Slack or Mattermost channel. If it does not, verify that the incoming webhook remains enabled and still targets a channel the integration can access.

Troubleshoot Slack or Mattermost delivery

If the test does not arrive:

Confirm that the saved URL belongs to the provider and workspace or server you are checking.
Confirm that the webhook still exists and still targets an accessible channel.
If the app or webhook was reinstalled or recreated, copy the new URL into Coolify and save it.
In Slack, confirm that the app remains authorized for the workspace and channel.
In Mattermost, confirm that incoming webhooks remain enabled in the server's integration settings.
Send another test before enabling production events.