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 Vigilmon → Monitors → 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:
- Monitors → New Heartbeat Monitor
- Set Expected interval to 10 minutes (2× the cron interval)
- 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:
- Alert Channels → Email → add your on-call email
- Attach to both HTTP monitors and the heartbeat
Slack
- Create a Slack Incoming Webhook for
#alerts - Alert Channels → Webhook → paste the URL
- 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.