Production Monitoring

CI testing runs before merge. Production monitoring answers a different question: does your live site look right, right now? It catches broken deploys, CDN failures, third-party script injection, ad layout corruption, and A/B test leakage — things that never touch a pull request.

There are two ways to run it: the CLI (self-hosted, cron it yourself) and the cloud scheduler (managed, runs on cadence for you).

CLI monitoring

The frontguard monitor command renders live URLs and alerts when visual drift exceeds a threshold.

frontguard monitor --url https://example.com,https://example.com/pricing --threshold 2

frontguard monitor --url https://example.com --interval 15 --webhook $SLACK_WEBHOOK

frontguard monitor --url http://localhost:3000 --watch

Each run stores a history entry per URL under --history-dir (default .frontguard/monitor-history). Inspect the trend at any time:

frontguard monitor --history --limit 50

As a plugin

Under the hood the command uses the monitor plugin, which you can also add to a config directly:

import { createMonitorPlugin } from '@frontguard/cli/plugins';

export default {
  baseUrl: 'https://example.com',
  plugins: [
    createMonitorPlugin({
      urls: ['https://example.com', 'https://example.com/pricing'],
      alertThreshold: 0.02, // 2%
      alerts: { webhook: process.env.SLACK_WEBHOOK },
      historyDir: '.frontguard/monitor-history',
    }),
  ],
};

Cloud monitoring (managed scheduler)

The cloud platform runs monitors for you on a Cloudflare Workers Cron trigger — no cron of your own. A monitor is a saved config (URL, routes, viewports, interval, alert threshold, channels). The scheduler queries due monitors, runs them in a sandbox, retries once on failure, prunes history per your plan, and fires alerts on regressions.

curl -X POST https://api.frontguard.dev/v1/monitors \
  -H "Authorization: Bearer $FRONTGUARD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Marketing site",
    "url": "https://example.com",
    "routes": ["/", "/pricing"],
    "viewports": [375, 1440],
    "intervalMinutes": 60,
    "alertThreshold": 0.02,
    "alerts": { "slack": "https://hooks.slack.com/services/…" }
  }'

Alerts support Slack, email, and PagerDuty, with deduplication and snooze — see the Cloud API guide. Production monitoring is a Business-plan feature.