tutorial

Monitoring Your Hybrids App with Vigilmon: Health Checks, Heartbeats & Uptime Alerts

Add production-grade monitoring to a Hybrids application — a health API, background job heartbeats, and instant alerts when your web component library or backend goes down.

Hybrids is a unique UI library for creating web components from plain objects and pure functions — no classes, no decorators, just straightforward JavaScript objects with property descriptors. But that simplicity disappears entirely the moment your app is down, your API is unreachable, or a background task is silently failing. Vigilmon gives you the visibility layer you need: continuous HTTP monitoring, heartbeat checks, and instant alerts routed to email or Slack.

What You'll Build

  • A health API endpoint for your Hybrids backend
  • Vigilmon HTTP monitors for your Hybrids app and backend
  • A heartbeat for scheduled background tasks
  • Alert channels (email and Slack)
  • An uptime badge as a reusable Hybrids web component

Prerequisites

  • A Hybrids project (npm install hybrids)
  • Node.js/Express backend for the health endpoint
  • A free Vigilmon account

Step 1: Add a Health Endpoint

Hybrids apps are SPAs backed by a separate server. Add a /health route to your Express backend:

// server.js
import express from "express";

const app = express();

app.get("/health", async (req, res) => {
  const checks = {};
  let degraded = false;

  // Database check
  try {
    // await db.query("SELECT 1");
    checks.database = "ok";
  } catch (err) {
    checks.database = `error: ${err.message}`;
    degraded = true;
  }

  // Cache check
  try {
    // await redisClient.ping();
    checks.cache = "ok";
  } catch (err) {
    checks.cache = `error: ${err.message}`;
    degraded = true;
  }

  res.status(degraded ? 503 : 200).json({
    status: degraded ? "degraded" : "ok",
    timestamp: new Date().toISOString(),
    checks,
  });
});

// Serve Hybrids SPA
app.use(express.static("dist"));
app.get("*", (req, res) => res.sendFile("dist/index.html", { root: "." }));

app.listen(process.env.PORT ?? 3000);

Test it:

curl http://localhost:3000/health | jq .
# {"status":"ok","timestamp":"2026-06-29T...","checks":{"database":"ok","cache":"ok"}}

Step 2: Configure Vigilmon HTTP Monitors

Log in to VigilmonMonitors → New Monitor:

Monitor 1: Hybrids SPA

| Field | Value | |---|---| | URL | https://yourapp.com/ | | Method | GET | | Expected status | 200 | | Expected body | A stable string from your HTML (e.g. app title) | | Check interval | 1 minute |

Monitor 2: Health API

| Field | Value | |---|---| | URL | https://yourapp.com/health | | Method | GET | | Expected status | 200 | | Check interval | 1 minute |

With both monitors, you cover two independent failure classes: the static/CDN serving layer and the backend/data layer.


Step 3: Heartbeat for Background Tasks

Background jobs — data sync, webhook delivery, session cleanup — can fail silently for days without anyone noticing. A Vigilmon heartbeat catches this by alerting when the expected ping doesn't arrive.

npm install node-cron
// scheduler.js
import cron from "node-cron";

const VIGILMON_HEARTBEAT_URL = process.env.VIGILMON_HEARTBEAT_URL ?? "";

async function pingHeartbeat() {
  if (!VIGILMON_HEARTBEAT_URL) return;
  try {
    await fetch(VIGILMON_HEARTBEAT_URL, { signal: AbortSignal.timeout(5000) });
  } catch {
    // Monitoring must never crash the job
  }
}

cron.schedule("*/10 * * * *", async () => {
  try {
    await syncData();
    await pingHeartbeat();
  } catch (err) {
    console.error("[scheduler] Data sync failed:", err);
    // Vigilmon alerts after the heartbeat window expires with no ping
  }
});

async function syncData() {
  // Your actual data sync logic
}

Set up the heartbeat in Vigilmon:

  1. Monitors → New Heartbeat Monitor
  2. Set Expected interval to 20 minutes (2× the cron interval for a grace window)
  3. Copy the ping URL to your .env:
VIGILMON_HEARTBEAT_URL=https://vigilmon.online/api/heartbeat/xxxxxxxx

Step 4: Display Uptime Status as a Hybrids Web Component

Hybrids lets you define custom elements as plain objects. Here's a status-badge component:

// src/components/status-badge.js
import { define, html } from "hybrids";

const StatusBadge = {
  badgeUrl: "https://vigilmon.online/api/badge/your-monitor-id.svg",
  statusUrl: "https://vigilmon.online/status/your-monitor-slug",

  render: ({ badgeUrl, statusUrl }) => html`
    <a
      href="${statusUrl}"
      target="_blank"
      rel="noopener noreferrer"
      aria-label="Service uptime status"
    >
      <img
        src="${badgeUrl}"
        alt="Uptime"
        width="120"
        height="20"
      />
    </a>
  `,
};

define({ tag: "status-badge", ...StatusBadge });

Use it in your HTML or another Hybrids component:

<!-- index.html -->
<script type="module" src="./src/components/status-badge.js"></script>

<footer>
  <status-badge></status-badge>
</footer>

Or compose it into your app shell component:

// src/components/app-shell.js
import { define, html } from "hybrids";
import "./status-badge.js";

const AppShell = {
  render: () => html`
    <div class="app">
      <main>
        <slot></slot>
      </main>
      <footer class="footer">
        <status-badge></status-badge>
      </footer>
    </div>
  `,
};

define({ tag: "app-shell", ...AppShell });

Step 5: Set Up Alert Channels

In Vigilmon's Alert Channels settings:

Email

  1. Alert Channels → Email → add your on-call email
  2. Attach to both HTTP monitors and the heartbeat

Slack

  1. Create a Slack Incoming Webhook for #alerts
  2. Alert Channels → Webhook → paste the URL
  3. Payload template:
{
  "text": "🚨 *{{ monitor.name }}* is DOWN\n{{ monitor.url }}\nStatus: {{ event.status }}\n<https://vigilmon.online|Open Vigilmon>"
}

Step 6: Verify Everything Works

# 1. Health endpoint responds correctly
curl -s https://yourapp.com/health | jq .

# 2. Simulate DB failure → confirm health returns 503
# Expected: Vigilmon alerts within 2 minutes

# 3. Remove VIGILMON_HEARTBEAT_URL → let the scheduler run
# Expected: heartbeat alert fires after the grace window

# 4. Vigilmon → "Test Alert" → confirm delivery to Slack/email

Summary

| Monitor | What It Catches | |---|---| | HTTP SPA check | CDN failures, broken static deploys | | HTTP health API | Database and cache failures | | Heartbeat | Scheduler crashes, silent sync failures |


Next Steps

  • Create separate monitors for staging vs. production
  • Use Vigilmon's response time graphs to spot latency regressions
  • Configure multi-channel alerting: email for low-severity, Slack for critical

Ready to get started? Sign up for Vigilmon free — have your first monitor running in under 5 minutes.

Monitor your app with Vigilmon

Free plan — 5 monitors, no credit card required. Up and running in 60 seconds.

Start free →