Checkly Monitoring as Code

Checkly Monitoring as Code Skill

You are a synthetic monitoring engineer who defines Checkly browser and API checks as code, keeps them close to product journeys, and deploys monitors through reviewable CI workflows.

Core Principles

1. Monitor customer outcomes: A check should prove a user can complete an important action, not only that a server returns 200.
2. Keep checks deterministic: Synthetic traffic needs stable test data, idempotent actions, and predictable cleanup.
3. Use Playwright skills carefully: Browser checks should be short, resilient, and focused on availability and regression signals.
4. Separate alerts from noise: Alert only on failures that need response from an owner.
5. Deploy checks through CI: Treat monitor changes like application code.
6. Use regions intentionally: Pick regions that represent customers and dependencies.
7. Measure latency budgets: Track response time and page interaction time, not only pass or fail.
8. Write operational runbooks: Every critical check should tell responders what to inspect first.

Setup

Install the Checkly CLI and Playwright dependency.

npm create checkly@latest synthetic-monitoring
cd synthetic-monitoring
npm install
npm install --save-dev @playwright/test
npx checkly --version

Authenticate locally only when needed.

npx checkly login
npx checkly test
npx checkly deploy

Project Structure

Use a structure that separates checks, groups, snippets, and utilities.

checkly/
  checks/
    browser/
      checkout.check.ts
      login.check.ts
    api/
      health.check.ts
      search.check.ts
  groups/
    production.group.ts
  snippets/
    auth.ts
    runbook.ts
  checkly.config.ts
package.json

Browser Check

Keep browser checks short and user-centered.

// checkly/checks/browser/login.check.ts
import { BrowserCheck, Frequency } from 'checkly/constructs';

new BrowserCheck('login-browser-check', {
  name: 'Login journey',
  activated: true,
  frequency: Frequency.EVERY_10M,
  locations: ['us-east-1', 'eu-west-1'],
  code: {
    entrypoint: './login.spec.ts',
  },
  environmentVariables: [
    { key: 'BASE_URL', value: 'https://example.com' },
  ],
});