tutorial

Monitoring Your Tram-One App with Vigilmon: Health Checks, Heartbeats & Uptime Alerts

Add production-grade monitoring to a Tram-One application — a health API, background job heartbeats, and instant alerts when your custom element-based app or backend goes down.

Tram-One is an opinionated web framework for building custom element-based applications, giving you a structured approach to component architecture without locking you into a heavyweight ecosystem. But structured code doesn't mean self-healing infrastructure. When your backend silently returns errors or a background process crashes overnight, Vigilmon is there: continuous HTTP monitoring, heartbeat checks, and instant alerts via email or Slack.

What You'll Build

  • A health API endpoint for your Tram-One app's backend (Node/Express)
  • Vigilmon HTTP monitors for your app shell and backend health route
  • A heartbeat for scheduled background tasks
  • Alert channels (email and Slack)
  • An uptime badge embedded in a Tram-One custom element

Prerequisites

  • A Tram-One project (initialized with npx tram-one new)
  • A Node.js backend to host your health endpoint
  • A free Vigilmon account

Step 1: Add a Health Endpoint

Tram-One renders custom elements in the browser. Add a health endpoint to the server that hosts your app:

// 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.execute("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;
  }

  // External API check
  try {
    const resp = await fetch("https://api.stripe.com/v1/", {
      signal: AbortSignal.timeout(3000),
    });
    checks.stripe = resp.status < 500 ? "ok" : `http_${resp.status}`;
  } catch {
    checks.stripe = "unreachable";
    degraded = true;
  }

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

// Serve Tram-One SPA
app.use(express.static("dist"));

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","stripe":"ok"}}

Step 2: Configure Vigilmon HTTP Monitors

Log in to VigilmonMonitors → New Monitor:

Monitor 1: Tram-One App Shell

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

Monitor 2: Health API

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

Two monitors cover two independent failure classes: the static hosting layer and the backend/data layer.


Step 3: Heartbeat for Background Tasks

Background jobs — data synchronization, notification dispatch, webhook ingestion — can crash silently. A Vigilmon heartbeat alerts you the moment an expected ping stops arriving.

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("*/5 * * * *", async () => {
  try {
    await syncExternalData();
    await pingHeartbeat();
  } catch (err) {
    console.error("[scheduler] Sync failed:", err);
    // No ping → Vigilmon alerts after the grace window expires
  }
});

async function syncExternalData() {
  // Your actual sync logic
}

Set up the heartbeat in Vigilmon:

  1. Monitors → New Heartbeat Monitor
  2. Set Expected interval to 10 minutes (2× the cron interval)
  3. Copy the ping URL to your .env:
VIGILMON_HEARTBEAT_URL=https://vigilmon.online/api/heartbeat/xxxxxxxx

Step 4: Display Uptime Status in a Tram-One Custom Element

Tram-One's define function makes it straightforward to create a reusable status badge component using its tagged template literals:

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

const BADGE_URL = "https://vigilmon.online/api/badge/your-monitor-id.svg";
const STATUS_URL = "https://vigilmon.online/status/your-monitor-slug";

define("status-badge", () => {
  return html`
    <a
      href="${STATUS_URL}"
      target="_blank"
      rel="noopener noreferrer"
      aria-label="Service uptime status"
      style="display:inline-flex;align-items:center"
    >
      <img
        src="${BADGE_URL}"
        alt="Uptime"
        width="120"
        height="20"
        onload="this.style.opacity=1"
        style="opacity:0;transition:opacity 0.2s"
      />
    </a>
  `;
});

Import the component and use it in your app:

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

define("my-app", () => {
  return html`
    <div>
      <main><!-- routes --></main>
      <footer>
        <status-badge></status-badge>
      </footer>
    </div>
  `;
});

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
curl -s https://yourapp.com/health | jq .

# 2. Break the DB connection string → confirm health returns 503
# Expected: Vigilmon alerts within 2 minutes

# 3. Unset 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 app shell check | CDN failures, broken static deploys | | HTTP health API | Database, cache, and third-party API failures | | Heartbeat | Scheduler crashes, silent sync failures |


Next Steps

  • Create separate monitors for staging vs. production
  • Use Vigilmon's response time graphs to correlate latency with Tram-One version upgrades
  • 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.

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