Website change monitoring that fires a webhook

Competitor pricing & packaging

Point a monitor at a rival’s public pricing URL and a CSS selector like #pricing or .plan-price. When plan names, prices, or footnote copy change, the text hash flips and email, Slack, Discord, or JSON fires. A selector or an ignore rule keeps cookie banners and rotating heroes quiet. That is useful before a sales call, a price match, or a “they shipped a new SKU” Slack message. One monitor is one URL — it does not crawl the rest of the site. How to monitor a pricing page.

Pro at 5 minutes is enough for most pricing pages. The alert you want is that the visible text moved.

Status pages and incident banners

Classic ping monitors miss a 200 OK page that swapped “All systems operational” for a yellow banner. Hash the status URL you actually read during incidents. Soft degradations show up as content.changed even when the status code stays 200.

Changelogs and release notes

Libraries, payment processors, and cloud vendors often publish a changelog with no feed, or a feed that lags the HTML. Watch the page, route the webhook into the same channel you use for deploys, and stop polling it by hand.

Policy / ToS / compliance

Fee schedules, data-processing addenda, and acceptable-use pages change quietly. A content hash turns “did this change since last quarter?” into an API answer. SignalWatch will not interpret the legal text. It tells you the visible text is different.

Automation builders

Create monitors from a script with the REST API and X-API-Key. OpenAPI lives at /docs. The dashboard is optional; the free plan is enough to prove the webhook path before you put it in production. Payload fields and the HMAC header are on the webhook page.

TLS certificate expiry

Every HTTPS monitor reads the certificate. cert.expiring fires inside 14 days, then again inside 3 — not on every poll. The same URL still reports text changes and downtime. Certificate alerts.