Website change monitoring that fires a webhook

Competitor pricing & packaging

Point a monitor at a rival’s public pricing URL and optionally a CSS selector like #pricing or .plan-price. When plan names, prices, or footnote copy change, the text hash flips and Slack/Discord/JSON fires. Cookie banners and rotating heroes do not count. That is useful before a sales call, a price match, or a “they shipped a new SKU” Slack message.

Interval: Pro at 5 minutes is enough for most pricing pages. You do not need a visual diff of the hero image — you need to know the HTML body 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 bytes are 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.