Slack Channel

The Slack channel allows you to send notifications to Slack channels via webhooks. This channel is built on top of the Webhook channel and supports all webhook features. It uses the Slack Incoming Webhooks API.

Batching

This channel does not support batching. Each notification is sent individually.

Configuration

import { createFacteur } from '@facteurjs/core'
import { slackWebhookChannel } from '@facteurjs/core/channels/slack'

export const facteur = createFacteur({
  discoverer: { searchDirectory: new URL('./notifications/', import.meta.url) },
  channels: {
    slack: slackWebhookChannel({
      // You can define multiple Slack webhooks, each with a unique name
      webhooks: {
        general: 'https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK',
        alerts: 'https://hooks.slack.com/services/YOUR/ALERT/WEBHOOK',
        marketing: 'https://hooks.slack.com/services/YOUR/MARKETING/WEBHOOK',
      },
    }),
  },
})

You can define multiple Slack webhooks, each with a unique name, or just a single default webhook. This is useful when you want to send certain notifications to specific Slack channels.

Configuration Options

Since the Slack channel uses the webhook channel internally, it supports the same configuration options:

• webhooks (optional): An object defining multiple named Slack webhooks
• webhookUrl (optional): A single default Slack webhook URL

Provide either webhooks or webhookUrl, not both. If both exist at runtime, webhookUrl takes precedence and the named webhooks are not registered.

The Slack channel also accepts the webhook security options: signingSecret, httpsOnly, followRedirects, timeout, and fetch. Slack does not check Standard Webhooks signatures, so signingSecret helps only when a proxy you run checks them. If your users provide Slack webhook URLs, use httpsOnly, timeout, and a fetch that blocks SSRF.

Targets

The Slack channel targets work exactly like webhook targets:

// Send to specific named webhooks
await facteur
  .notification(MyNotification)
  .via({
    slack: {
      general: true,
      marketing: true,
    },
  })
  .send()

// Or send to an arbitrary Slack webhook URL
await facteur
  .notification(MyNotification)
  .via({
    slack: {
      webhookUrl: 'https://hooks.slack.com/services/CUSTOM/TENANT/WEBHOOK',
    },
  })
  .send()

Target Properties

• Named webhooks: Include only the names to call. The current implementation selects keys regardless of their boolean value: omit a name to exclude it; false does not disable it.
• webhookUrl (optional): Send to an arbitrary Slack webhook URL

Slack Message Features

When creating notifications for Slack, you can use rich formatting features:

import { Notification } from '@facteurjs/core/types'
import { SlackMessage } from '@facteurjs/core/channels/slack'

export default class SlackNotification extends Notification<undefined> {
  asSlackMessage() {
    return SlackMessage.create()
      .setText('Hello from Facteur!')
      .setChannel('#general')
      .setBotUsername('Bot Name')
      .setBotIconEmoji(':robot_face:')
  }
}

For more details about webhook configuration and targeting, see the Webhook channel documentation.