Website monitoring
for developers

import { run } from '@alosha/monitor'

const report = await run({
  checks: [{
    name: 'Login flow',
    url: 'https://app.example.com/login',
    steps: [
      { action: 'fill',  selector: '#email',    value: process.env.TEST_EMAIL! },
      { action: 'fill',  selector: '#password', value: process.env.TEST_PASS! },
      { action: 'click', selector: 'button[type=submit]' },
      { action: 'waitForURL', value: '**/dashboard' }
    ],
    assertions: [{ type: 'visible', selector: '[data-test=user-menu]' }]
  }]
})

// Break the build if any check failed.
if (report.failed > 0) process.exit(1)

# .github/workflows/synthetics.yml
name: Synthetics
on:
  schedule:
    - cron: '*/15 * * * *'   # every 15 minutes
  workflow_dispatch:          # ...and on demand

jobs:
  monitor:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 22
      - run: npm ci
      - run: npx playwright install --with-deps chromium
      # 'monitor run' exits 1 on failure — the run goes red AND
      # the Slack notifier in monitor.config.ts fires.
      - run: npx monitor run
        env:
          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}

import { watch } from '@alosha/monitor'

// Runs continuously, firing each check on its own interval.
await watch({
  checks: [
    { name: 'Homepage', url: 'https://example.com', interval: '1m', maxResponseTimeMs: 2000 },
    { name: 'Checkout', url: 'https://example.com/checkout', interval: '5m' }
  ],
  notify: { slack: { webhookUrl: process.env.SLACK_WEBHOOK_URL! } }
})

import { run } from '@alosha/monitor'

const report = await run({
  checks: [
    { name: 'Checkout', url: 'https://app.example.com/checkout', maxResponseTimeMs: 3000 }
  ]
})

// No built-in PagerDuty notifier — page on-call yourself from the
// structured report via the Events API v2.
const down = report.results.filter((r) => r.status === 'fail')

await Promise.all(down.map((r) =>
  fetch('https://events.pagerduty.com/v2/enqueue', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      routing_key: process.env.PAGERDUTY_ROUTING_KEY,
      event_action: 'trigger',
      dedup_key: `monitor-${r.name}`,        // collapse repeats into one incident
      payload: {
        summary: `${r.name} is DOWN — ${r.error ?? 'check failed'}`,
        source: r.url,
        severity: 'critical'
      }
    })
  })
))

if (report.failed > 0) process.exit(1)