Overview
What DiffMon monitors and how it detects changes across web pages and JSON APIs.
Overview
DiffMon tracks critical URLs and JSON endpoints, hashes normalized responses, and alerts you when a meaningful change happens.
What DiffMon does
- Fetches pages and APIs on a schedule with rate limiting.
- Normalizes HTML/JSON so cosmetic noise does not spam alerts.
- Stores snapshots, hashes, and diffs so you can explain what changed.
- Renders JS-heavy pages with Browser Render when plain fetch is not enough.
When to use it
- Launch monitors for marketing pages, docs, sitemaps, or feature flags you must watch.
- Track JSON feeds or partner APIs for contract drift without running your own worker fleet.
- Keep stakeholders aligned with emailed diffs that include request IDs.
How the loop runs
The worker respects your plan’s interval, enforces global/domain rate limits, and retries transient errors with jitter.
const result = await fetchMonitor(monitor, requestId);
if (!result.error && result.contentHash !== lastHash) {
await dispatchNotification(monitor.id, { type: 'diff.detected', payload: diff });
}Next steps
- Pick a target type (website vs API) and review the ignore rules.
- For SPA or hydrated pages, configure Browser Render.
- Enable alerts and webhooks so changes flow to the right channel.
- Check the audit log to verify who created or paused a monitor.