SlackAlertChannel Construct

Learn how to configure Slack alert channels with the Checkly CLI.

Learn more about Slack alerts in the Slack Alerts documentation.

Use Slack Alert Channels to send notifications to Slack channels when checks fail or recover. The examples below show how to configure Slack alerting for different scenarios.

Basic Example

import { SlackAlertChannel } from "checkly/constructs"

const slackChannel = new SlackAlertChannel("slack-channel-1", {
  url: new URL(
    "https://hooks.slack.com/services/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"
  ),
  channel: "#ops",
})

import { SlackAlertChannel } from "checkly/constructs"

const slackChannel = new SlackAlertChannel("team-slack-channel", {
  url: new URL(
    "https://hooks.slack.com/services/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"
  ),
  channel: "#monitoring-alerts",
  sendRecovery: true,
  sendFailure: true,
  sendDegraded: true,
  sslExpiry: true,
  sslExpiryThreshold: 30,
})

Configuration

Slack Alert Channel

Configure Slack-specific settings:

Parameter	Type	Required	Default	Description
url	URL	✅	-	Slack webhook URL for incoming messages
channel	string	❌	-	Target Slack channel (e.g., ‘#ops’, ‘@user’)

General Alert Channel

Configure common alert channel properties:

Property	Type	Required	Default	Description
sendRecovery	boolean	❌	true	Send notifications when checks recover
sendFailure	boolean	❌	true	Send notifications when checks fail
sendDegrade	boolean	❌	false	Send notifications when checks degrade (API checks only)
sslExpiry	boolean	❌	false	Send notifications for SSL certificate expiry
sslExpiryThreshold	number	❌	30	Days before SSL expiry to send notification

Slack Alert Channel Options

url · URL · required

Slack webhook URL for incoming messages. This is the endpoint where Checkly will send alert notifications.

Usage:

new SlackAlertChannel("slack-channel", {
  url: new URL(
    "https://hooks.slack.com/services/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"
  ),
  channel: "#alerts",
})

Examples:

Direct URL

const slackChannel = new SlackAlertChannel("direct-slack", {
  url: new URL(
    "https://hooks.slack.com/services/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"
  ),
  channel: "#monitoring",
})

const secureSlack = new SlackAlertChannel("secure-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!), // Store securely
  channel: "#alerts",
})

// Different webhook URLs for different teams
const devSlack = new SlackAlertChannel("dev-slack", {
  url: new URL(process.env.DEV_SLACK_WEBHOOK_URL!),
  channel: "#dev-alerts",
})

const opsSlack = new SlackAlertChannel("ops-slack", {
  url: new URL(process.env.OPS_SLACK_WEBHOOK_URL!),
  channel: "#ops-alerts",
})

Use cases: Team notifications, webhook integration, secure credential storage, multi-team alerting.

channel · string

Target Slack channel or user for notifications. Can override the default channel configured in the webhook.

Usage:

new SlackAlertChannel("channel-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#ops", // Send to #ops channel
})

Examples:

Channel Notifications

const channelSlack = new SlackAlertChannel("channel-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#monitoring-alerts", // Public channel
})

const dmSlack = new SlackAlertChannel("dm-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "@john.doe", // Direct message to user
})

const criticalSlack = new SlackAlertChannel("critical-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#critical-alerts",
})

const performanceSlack = new SlackAlertChannel("performance-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#performance-monitoring",
})

const securitySlack = new SlackAlertChannel("security-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#security-alerts",
})

Use cases: Team-specific alerts, direct notifications, alert categorization, noise management.

General Alert Channel Options

sendRecovery · boolean

Whether to send notifications when checks recover from failure or degraded state.

Usage:

new SlackAlertChannel("recovery-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#alerts",
  sendRecovery: true, // Send recovery notifications
})

Examples:

Recovery Notifications

const opsSlack = new SlackAlertChannel("ops-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#ops",
  sendRecovery: true, // Get notified when issues are resolved
  sendFailure: true,
})

const alertsSlack = new SlackAlertChannel("alerts-only", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#critical-alerts",
  sendRecovery: false, // Only failures, no recovery notifications
  sendFailure: true,
  sendDegraded: false,
})

Use cases: Recovery confirmation, operational awareness, noise reduction.

sendFailure · boolean

Whether to send notifications when checks fail.

Usage:

const slackAlert = new SlackAlertChannel("failure-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#alerts",
  sendFailure: true, // Send failure notifications
})

Examples:

Critical Failures Only

const criticalSlack = new SlackAlertChannel("critical-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#critical-alerts",
  sendFailure: true, // Critical failures
  sendRecovery: true,
  sendDegraded: false, // No degraded alerts
})

const comprehensiveSlack = new SlackAlertChannel("all-notifications", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#monitoring",
  sendFailure: true, // All failures
  sendRecovery: true,
  sendDegraded: true,
})

Use cases: Incident response, failure monitoring, operational alerting.

sendDegraded · boolean

Whether to send notifications when API checks degrade (performance thresholds exceeded but not failed).

Usage:

new SlackAlertChannel("performance-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#performance",
  sendDegraded: true, // Send degraded performance notifications
})

Examples:

Performance Monitoring

const performanceSlack = new SlackAlertChannel("performance-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#performance",
  sendRecovery: true,
  sendFailure: true,
  sendDegraded: true, // Alert on degraded performance
})

new ApiCheck("performance-check", {
  name: "API Performance Check",
  maxResponseTime: 3000,
  degradedResponseTime: 1500, // Triggers degrade alerts
  alertChannels: [performanceSlack],
  request: {
    method: "GET",
    url: "https://api.example.com/slow-endpoint",
  },
})

const criticalOnlySlack = new SlackAlertChannel("critical-only", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#critical-alerts",
  sendFailure: true,
  sendRecovery: true,
  sendDegraded: false, // Only complete failures, not performance issues
})

Use cases: Performance monitoring, early warning systems, SLA tracking.

sslExpiry · boolean

Whether to send notifications for SSL certificate expiry warnings.

Usage:

new SlackAlertChannel("security-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#security",
  sslExpiry: true,
  sslExpiryThreshold: 30, // Alert 30 days before expiry
})

Examples:

Security Team Alerts

const securitySlack = new SlackAlertChannel("security-slack", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#security",
  sendRecovery: false,
  sendFailure: true,
  sslExpiry: true,
  sslExpiryThreshold: 7, // Alert 7 days before expiry
})

new ApiCheck("ssl-cert-check", {
  name: "SSL Certificate Check",
  alertChannels: [securitySlack],
  request: {
    method: "GET",
    url: "https://secure.example.com",
  },
})

const earlyWarningSlack = new SlackAlertChannel("ssl-early-warning", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#devops",
  sslExpiry: true,
  sslExpiryThreshold: 60, // Alert 60 days before expiry for planning
})

Use cases: Certificate management, security compliance, proactive maintenance.

sslExpiryThreshold · number

Number of days before SSL certificate expiry to send notifications. Only relevant when sslExpiry is enabled.

Usage:

new SlackAlertChannel('ssl-monitoring', {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: '#devops',
  sslExpiry: true,
  sslExpiryThreshold: 30 // Alert 30 days before expiry
})

Examples:

Last Minute Alert

// Alert close to expiry for urgent action
new SlackAlertChannel("ssl-urgent", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#security",
  sslExpiry: true,
  sslExpiryThreshold: 7, // 7 days notice
})

// Create multiple channels with different thresholds
const earlyWarning = new SlackAlertChannel("ssl-early", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#planning",
  sslExpiry: true,
  sslExpiryThreshold: 90, // Planning notification
})

const urgentWarning = new SlackAlertChannel("ssl-urgent", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#oncall",
  sslExpiry: true,
  sslExpiryThreshold: 7, // Urgent notification
})

Use cases: Certificate renewal planning, compliance management, operational scheduling.

Examples

Team Channel Alerts

    import { SlackAlertChannel, ApiCheck } from "checkly/constructs"

    const teamSlack = new SlackAlertChannel("team-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "#dev-team",
    })

    new ApiCheck("api-health-check", {
      name: "API Health Check",
      alertChannels: [teamSlack],
      request: {
        method: "GET",
        url: "https://api.acme.com/health",
      },
    })

    import { ApiCheck, SlackAlertChannel } from "checkly/constructs"

    const criticalSlack = new SlackAlertChannel("critical-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "#critical-alerts",
      sendRecovery: true,
      sendFailure: true,
      sendDegraded: false, // Only failures for critical alerts
    })

    new ApiCheck("payment-api-check", {
      name: "Payment API Check",
      alertChannels: [criticalSlack],
      tags: ["critical", "payment"],
      request: {
        method: "GET",
        url: "https://api.acme.com/payments/health",
      },
    })

    import { ApiCheck, SlackAlertChannel } from "checkly/constructs"

    const dmSlack = new SlackAlertChannel("dm-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "@john.doe", // Direct message to user
      sendFailure: true,
      sendRecovery: false, // Only notify on failures
    })

    new ApiCheck("personal-project-check", {
      name: "Personal Project Check",
      alertChannels: [dmSlack],
      request: {
        method: "GET",
        url: "https://personal-project.example.com",
      },
    })

    import { ApiCheck, SlackAlertChannel } from "checkly/constructs"

    const securitySlack = new SlackAlertChannel("security-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "#security",
      sendFailure: true,
      sendRecovery: false,
      sslExpiry: true,
      sslExpiryThreshold: 7, // Alert 7 days before SSL expires
    })

    new ApiCheck("ssl-cert-check", {
      name: "SSL Certificate Check",
      alertChannels: [securitySlack],
      request: {
        method: "GET",
        url: "https://secure.acme.com",
      },
    })

    import { ApiCheck, SlackAlertChannel } from "checkly/constructs"

    const devSlack = new SlackAlertChannel("dev-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "#development",
      sendDegraded: true,
    })

    const opsSlack = new SlackAlertChannel("ops-slack", {
      url: new URL("https://hooks.slack.com/services/YOUR/WEBHOOK/URL"),
      channel: "#operations",
      sendFailure: true,
      sendRecovery: true,
    })

    new ApiCheck("multi-channel-check", {
      name: "Multi-Channel Notifications",
      alertChannels: [devSlack, opsSlack],
      request: {
        method: "GET",
        url: "https://api.acme.com/important",
      },
    })

Setting Up Slack Webhooks

Find more information on how to set up a new Slack webhook in the Slack alert channel documentation.

Environment Variables

Store your Slack webhook URL securely using environment variables:

const slackChannel = new SlackAlertChannel("slack-channel", {
  url: new URL(process.env.SLACK_WEBHOOK_URL!),
  channel: "#monitoring",
})

# .env
SLACK_WEBHOOK_URL=https://hooks.slack.com/services/YOUR/WEBHOOK/URL

Webhook Security: Keep your Slack webhook URLs secure. Anyone with access to the URL can send messages to your Slack channels.

Channel Override: The channel parameter can override the default channel configured in your Slack webhook. Use #channel-name for channels or @username for direct messages.