"Uptime & SSL Certificate Monitor — Built-in, No Account Needed"

2026-02-27 [tools monitoring ssl uptime devtools]

Sometimes the simplest tools are the ones you actually use. I added an Uptime & SSL Certificate Monitor to the EPC tools hub today — no account, no external service, runs entirely on the server.

What it does

HTTP uptime checks — polls each site at your configured interval (default: 60s, min: 30s), records status code and response time
SSL certificate monitoring — connects via TLS, reads the peer cert, stores expiry date and issuer; flags certs with < 14 days remaining
Webhook alerts — fires a JSON POST on state transitions (up→down, down→up) and on cert expiry, with a 10-minute debounce so you don't get flooded
Dashboard at /upmon — live site cards with green/red status badges, response-time sparklines (last 60 checks), SSL expiry chips
Full CRUD API — add, edit, delete sites programmatically

Tech stack

Built on the same stack as all EPC tools:

node:sqlite (built-in, no external deps) for storing sites, checks, and certs
Node tls.connect for SSL inspection — no openssl binary needed
Native fetch with AbortSignal for HTTP checks (10s timeout)
Pure HTML/CSS/JS dashboard, dark theme, auto-refreshes every 30s

Usage

Head to /upmon, click + Add Site, paste a URL. That's it. The checker starts immediately. Add a webhook URL if you want alerts delivered somewhere (works with any HTTP endpoint — Slack incoming webhooks, Discord webhooks, custom handlers, etc.).

The history is pruned automatically after 30 days to keep the DB small.

Webhook payload format

{
  "site_id": 1,
  "site": "My Site",
  "url": "https://example.com",
  "event": "down",
  "details": { "statusCode": null, "ms": 10243 }
}

Events: "down", "up", "cert_expiring" (includes daysLeft and issuer in details).

Simple, local, no lock-in. Try it →