Slack

Two ways to reach Slack. Pick one.

Method	Use it when
Incoming webhook	You want one channel and the least setup. Recommended
Bot token	You want one contact point that can post to different channels, or your workspace does not allow webhooks

Incoming webhook

1. Create the webhook in Slack

1. Go to api.slack.com/apps and Create New App → From scratch. Name it something recognisable, such as xScaler Alerts, and pick your workspace.
2. Open Incoming Webhooks and turn it on.
3. Add New Webhook to Workspace, choose the channel, and Allow.
4. Copy the webhook URL. It is on hooks.slack.com, with three path segments after /services/: a team ID, a webhook ID and a secret.

2. Create the contact point

Insights → Alerting → Contact points → New contact point, type Slack.

Field	Value
Webhook URL	The URL you copied
Recipient	Leave blank

Then Test.

A webhook URL is bound to one channel

Slack ties the webhook to the channel you picked when you created it. The Recipient field cannot move messages to another channel over a webhook. For a second channel, create a second webhook, or use a bot token.

Bot token

1. Create the app and scopes

1. Create an app at api.slack.com/apps as above.
2. Open OAuth & Permissions, and under Bot Token Scopes add chat:write. Add chat:write.public as well if you want it to post in public channels it has not been invited to.
3. Install to Workspace, then copy the Bot User OAuth Token. It starts with xoxb-.
4. In Slack, invite the bot to the channel: /invite @xScaler Alerts.

2. Create the contact point

Field	Value
Recipient	#alerts, or a user ID for a direct message
API token	The xoxb- token
Webhook URL	Leave blank

Optional fields

Field	What it does
Username	Overrides the display name on the message
Icon emoji	The avatar, for example :rotating_light:
Title	Replaces the message title. Takes a template
Message body	Replaces the message text. Takes a template
Mention users	Slack user IDs to mention, comma-separated, for example U012AB3CD

Mention users takes IDs rather than handles. Find one in Slack under Profile → More → Copy member ID.

What arrives

One message per notification group, with a coloured attachment: red while firing, green when resolved. The title is the first alert's summary annotation, and the body lists each alert in the group with its labels.

To change the wording, write a template and put it in Title or Message body. See Notification templates.

Common failures

Delivery attempt says	Cause
404	The webhook was revoked, or the app was removed from the workspace. Create a new webhook
invalid_auth	The bot token is wrong or was rotated
channel_not_found	The bot is not in that channel. Invite it, or add chat:write.public
no webhook URL or token setting	Neither field is filled in
no recipient channel for token delivery	Token mode needs a Recipient
Sent, nothing in Slack	The webhook points at a different channel than you think. Check it in Slack under the app's Incoming Webhooks

Use Test after any change. It posts a real message to the channel.