---
title: Slack
description: Post WatchFor alerts to a Slack channel with an incoming webhook — colored, enriched messages and grouped summaries during storms.
canonical: https://watchfor.io/docs/notifications/slack
---

# Slack

Post WatchFor alerts to a Slack channel with an incoming webhook — colored, enriched messages and grouped summaries during storms.

WatchFor posts to Slack through an **incoming webhook**: a URL Slack gives you
for one channel. No Slack app of ours to install and no OAuth — you create the
webhook in your workspace and paste the URL.

## Setup

### Create an incoming webhook in Slack
Go to [api.slack.com/apps](https://api.slack.com/apps) → **Create New App**
(from scratch) → open **Incoming Webhooks** → switch it **On** → **Add New
Webhook to Workspace** → pick the channel that should receive alerts → copy
the URL (`https://hooks.slack.com/services/…`).

### Add the channel in WatchFor
Go to **Alerting → Channels & contacts → Add Channel → Slack**, paste the **Webhook
URL**, attach the [contact groups](/docs/notifications/contact-groups) it
should serve and save.

The optional **Channel**, **Bot Username** and **Icon Emoji** fields override
where and how the message appears. Slack honors these only for legacy
custom-integration webhooks; app-based webhooks (the kind created above)
always post to the channel chosen when the webhook was created.

### Send a test
**⋯ → Send test** on the channel posts a `[TEST]` message to the Slack
channel within a couple of seconds.

## What alerts look like

Each incident is a colored message (red critical, amber warning, green
recovery, gray administrative close) with the standard title
(`🔴 DOWN: API (prod)`), the diagnosis, **Expected** vs **Detected** values,
target, severity, start time, the confirming locations and a link to the
incident. Recoveries add the outage duration.

When several incidents open or resolve within the
[grouping window](/docs/notifications#grouping-during-a-storm), the channel
receives one summary message — `🔴 5 new incidents` with one linked line per
monitor — instead of five separate posts.

## Tips

- Use two Slack channels with different **severity filters** — for example
  `#alerts` for everything and `#incidents-critical` with only *Critical*
  ticked — rather than one noisy room.
- The webhook URL is a secret: WatchFor stores it encrypted and masks it in
  the dashboard. If it leaks, regenerate it in Slack and update the channel.
- If Slack removes the app or the channel is archived, deliveries fail; you
  will see them as **Failed** in
  [notification history](/docs/notifications/history) with Slack's error.

---

Canonical page: https://watchfor.io/docs/notifications/slack · All docs: https://watchfor.io/docs · Site guide: https://watchfor.io/llms.txt