Alert - Khanh Docs

The Alert resource allows you to create and manage alerts that notify you when metrics exceed or fall below specified thresholds in PostHog.

Example Usage#

Basic Alert#

import * as posthog from "pulumi-posthog";const errorAlert = new posthog.Alert("high-errors", {    name: "High Error Rate",    // Use the numeric insight ID from PostHog (find in insight URL or API)    insight: 12345,    enabled: true,    thresholdType: "absolute",    thresholdUpper: 100,    // Array of PostHog user IDs to notify (find in user settings)    subscribedUsers: [67890],});

const signupAlert = new posthog.Alert("low-signups", {    name: "Low Signup Alert",    // Get insight ID from PostHog insight URL or API    insight: 12345,    enabled: true,    thresholdType: "absolute",    thresholdLower: 10, // Alert when below 10 signups    // Get user IDs from PostHog user settings or API    subscribedUsers: [67890, 67891],});

Percentage Change Alert#

const growthAlert = new posthog.Alert("growth-alert", {    name: "Revenue Growth Alert",    insight: 23456,    enabled: true,    thresholdType: "percentage",    thresholdLower: -10, // Alert on 10% decrease    thresholdUpper: 50, // Alert on 50% increase    subscribedUsers: [67890],});

Daily Check Alert#

const dailyAlert = new posthog.Alert("daily-check", {    name: "Daily Active Users Check",    insight: 34567,    enabled: true,    thresholdType: "absolute",    thresholdLower: 1000,    calculationInterval: "daily",    subscribedUsers: [67890],});

Weekend-Skipping Alert#

const weekdayAlert = new posthog.Alert("weekday-only", {    name: "Weekday Metrics Alert",    insight: 45678,    enabled: true,    thresholdType: "absolute",    thresholdUpper: 500,    skipWeekend: true, // Don't check on weekends    subscribedUsers: [67890],});

Series-Specific Alert#

const seriesAlert = new posthog.Alert("series-alert", {    name: "Specific Metric Alert",    insight: 56789,    enabled: true,    thresholdType: "absolute",    thresholdUpper: 200,    seriesIndex: 0, // Monitor first series in multi-series insight    subscribedUsers: [67890],});

Resource Properties#

Required Arguments#

insight (number): Numeric ID of the insight this alert monitors
thresholdType (string): Type of threshold - "absolute" for fixed values or "percentage" for relative changes
subscribedUsers (number[]): List of user IDs to notify when the alert fires

Optional Arguments#

name (string): Alert name
enabled (boolean): Whether alert is enabled (default: true)
thresholdLower (number): Lower bound of the threshold - alert fires when value goes below this
thresholdUpper (number): Upper bound of the threshold - alert fires when value goes above this
calculationInterval (string): How often to check - "hourly", "daily", "weekly", or "monthly"
conditionType (string): Condition type - "absoluteValue", "relativeIncrease", or "relativeDecrease"
seriesIndex (number): Index of the trend series to monitor (0-based)
checkOngoingInterval (boolean): Whether to check the ongoing (incomplete) interval
skipWeekend (boolean): Whether to skip checking the alert on weekends

Attributes#

All configured properties

Threshold Types#

Absolute Value#

Fixed numeric thresholds:

const alert = new posthog.Alert("absolute-alert", {    name: "Absolute Threshold",    insight: 12345,    thresholdType: "absolute",    thresholdLower: 50,  // Alert when below 50    thresholdUpper: 200, // Alert when above 200    subscribedUsers: [67890],});

Percentage Change#

Relative change thresholds:

const alert = new posthog.Alert("percentage-alert", {    name: "Percentage Change",    insight: 12345,    thresholdType: "percentage",    thresholdLower: -20, // Alert on 20% decrease    thresholdUpper: 50,  // Alert on 50% increase    subscribedUsers: [67890],});

Calculation Intervals#

Hourly#

Check metrics every hour:

calculationInterval: "hourly"

Daily#

Check once per day:

calculationInterval: "daily"

Weekly#

Check once per week:

calculationInterval: "weekly"

Monthly#

Check once per month:

calculationInterval: "monthly"

Best Practices#

1. Use Descriptive Names#

// ✅ Goodconst alert = new posthog.Alert("critical-error-spike", {    name: "Critical: Error Rate Spike (>100/hour)",});// ❌ Avoidconst alert = new posthog.Alert("alert1", {    name: "Alert 1",});

2. Set Appropriate Thresholds#

// Start with conservative thresholdsconst alert = new posthog.Alert("signup-alert", {    name: "Low Signup Rate",    insight: 12345,    thresholdType: "absolute",    thresholdLower: 50, // Alert if below normal baseline    subscribedUsers: [67890],});

3. Notify the Right People#

// Production alerts - notify on-call teamconst prodAlert = new posthog.Alert("prod-critical", {    name: "Production Critical Alert",    insight: 12345,    thresholdType: "absolute",    thresholdUpper: 1000,    subscribedUsers: [111, 222, 333], // On-call team});// Business alerts - notify stakeholdersconst bizAlert = new posthog.Alert("revenue-drop", {    name: "Revenue Drop Alert",    insight: 23456,    thresholdType: "percentage",    thresholdLower: -10,    subscribedUsers: [444, 555], // Business team});

Common Use Cases#

Error Rate Monitoring#

const errorMonitor = new posthog.Alert("error-monitor", {    name: "High Error Rate Detection",    insight: 12345,    enabled: true,    thresholdType: "absolute",    thresholdUpper: 50, // Alert when errors exceed 50    calculationInterval: "hourly",    subscribedUsers: [67890],});

Conversion Drop Detection#

const conversionAlert = new posthog.Alert("conversion-drop", {    name: "Conversion Rate Drop",    insight: 23456,    enabled: true,    thresholdType: "percentage",    thresholdLower: -15, // Alert on 15% drop    calculationInterval: "daily",    subscribedUsers: [67890, 67891],});

Traffic Spike Alert#

const trafficSpike = new posthog.Alert("traffic-spike", {    name: "Unusual Traffic Spike",    insight: 34567,    enabled: true,    thresholdType: "percentage",    thresholdUpper: 100, // Alert on 100% increase    calculationInterval: "hourly",    subscribedUsers: [67890],});

Troubleshooting#

Alert Not Firing#

Issue: Alert doesn't trigger when threshold is exceeded

Solution:

Verify the alert is enabled
Check calculation interval matches expectation
Confirm insight ID is correct
Ensure threshold values are set appropriately

Wrong Users Notified#

Issue: Incorrect users receiving alerts