Assertions: Alerts only for changes that matter

Netonica records every change it sees on a site. Assertions decide which changes reach you: tick what must stay true, and hear when it stops being true.

Most changes are routine. A certificate renews, someone tidies a record, and a header gains a directive. A feed of every one becomes a list nobody reads, and the change that mattered waits in it unread.

Ticks say what must stay true

Each check offers assertions to tick, and a new monitor starts with the useful ones ticked. Every scan judges them, and you hear when one breaks and again when it recovers. Netonica still keeps the full change history, and alerts on every change are one switch away.

Assertions come in three shapes:

• Standard assertions ask yes or no about the site now: Certificate trusted or Not expired.
• Thresholds are standard assertions with a setting, such as how early to warn before a certificate expires.
• Pins hold the site to a value you approved, such as the certificate's issuer or the security contacts. Nothing pins automatically.

Pins and saved values

No standard assertion can say which certificate authority is right for your site, but you can. After the first scan, you pin the issuer you see, say Let's Encrypt. When a renewal arrives from Google Trust Services instead, the change reads:

Issuing CA changed

If you planned the move, pin the new issuer. If you didn't, that's the alert you wanted.

Some pins only care about direction. No new tools lets a list shrink but alerts when it grows. No pinned names removed lets a certificate add names but not drop one.

One fault raises one alert

When a scan can't see what an assertion reads, the assertion is unknown, not broken. A missing security.txt breaks File present and nothing else. And a value that vanishes from the file never matches a pin that held something.

Pins do most of the work in the security.txt check, the agent card check, and the Model Context Protocol (MCP) check.