Perimeter Watch

Passive external-perimeter monitoring for web agencies. We watch the public metadata around your client domains — cert expiries, dangling subdomain records, domain expiries, lookalike domains. Nothing touches your systems. No credentials, no access. We only ask for names. Checks run weekly. Alerts are sent after each weekly scan when findings appear. Delivery is best-effort — see Terms.

The four checks

Every run covers the same four checks on every domain you register. Each run produces a one-page brief with evidence.

TLS certificate expiry

Alert when a tracked domain's certificate enters a <14-day expiry window — before a client's site shows an interstitial warning page.

source: Certificate Transparency logs

Dangling DNS / subdomain takeover

Fingerprint subdomains for dangling records that point at claimable services — a known hijack path for staging and legacy subdomains.

source: can-i-take-over-xyz fingerprints

Domain lifecycle

Registrar expiry monitoring: alert when a client domain enters a <21-day renewal window — the failure nobody notices until the site is gone.

source: public registrar records

Lookalike domains

Watch Certificate Transparency logs for typo and hyphen variants of your domains, flagged only when the variant has live DNS.

source: CT logs · DNS resolution

What this is not

Stated plainly, so nobody is surprised:

  • No port scans
  • No crawling
  • No active testing
  • No takedowns
  • No fixes
  • Not a pentest

Passive public metadata only. We read what is already public. If it requires touching your systems, we don't do it.

Pricing

Flat monthly pricing. Cancel any time.

Cancellation stops the next billing cycle. No partial-month refunds. Domain lists and briefs are deleted within 7 days of cancellation — see Terms.

Lite
$9/mo
3 domains
  • All four checks on every run
  • One-page brief with evidence
Start Lite

Your email is collected at checkout by Stripe. Weekly briefs are sent to that address. Nothing else is required.

Agency
$19/mo
10 domains
  • All four checks on every run
  • One-page brief with evidence
Start Agency

Your email is collected at checkout by Stripe. Weekly briefs are sent to that address. Nothing else is required.

Payments are processed by Stripe. Cancel any time — see Terms.

Sample brief

This is a real brief from 2026-09-03 for a real domain, lightly formatted for the web.

● GREEN — all clear ● AMBER — attention needed ● RED — act now
PERIMETER WATCH — BRIEF ────────────────────────────────────────────────── DOMAIN: gasstationpermit.com RUN: 2026-09-03 RATING: ● GREEN — all checks OK COVERAGE: tls · domain_lifecycle · dangling_dns · lookalikes ● tls — OK Evidence: Certificate Transparency log (crt.sh) Certificate expires 2026-11-29 · 87 days remaining Issuer: Let's Encrypt ● domain_lifecycle — OK Registrar expiry 2027-06-18 · 287 days remaining ● dangling_dns — OK 50 subdomains checked · none dangling ● lookalikes — OK 4 variants queried · none registered ────────────────────────────────────────────────── NOT IN SCOPE: port scans · crawling · active testing · takedowns · fixes. Passive public metadata only.

How to start

Get a free one-page perimeter snapshot. Instant, no signup.

No confirmation, no check — we don't run briefs on domains without authority. Nothing is installed, nothing is touched: public records only.