How to Monitor Your Deno 2 Application with Vigilmon

Deno 2 is the TypeScript-first runtime that ships with built-in security, a standard library, and first-class npm compatibility. If you're running Deno in production, here's how to add health checks and connect to Vigilmon for uptime monitoring.

Quick Health Endpoint for Deno 2

Using Deno.serve (built-in)

// server.ts
Deno.serve({ port: 8000 }, (req) => {
  const url = new URL(req.url);

  if (url.pathname === '/health') {
    return new Response(
      JSON.stringify({
        status: 'ok',
        runtime: 'deno',
        version: Deno.version.deno,
        uptime: performance.now() / 1000,
        timestamp: new Date().toISOString(),
      }),
      {
        status: 200,
        headers: { 'Content-Type': 'application/json' },
      }
    );
  }

  return new Response('Hello from Deno 2!');
});

console.log('Server running on http://localhost:8000');

With Hono on Deno

// main.ts
import { Hono } from 'npm:hono';

const app = new Hono();

app.get('/health', (c) => {
  return c.json({
    status: 'ok',
    runtime: 'deno',
    version: Deno.version.deno,
    timestamp: new Date().toISOString(),
  });
});

app.get('/', (c) => c.text('Hello Hono on Deno!'));

Deno.serve({ port: 8000 }, app.fetch);

With Fresh Framework

For Fresh apps, add a health route in routes/:

// routes/health.ts
import { Handlers } from '$fresh/server.ts';

export const handler: Handlers = {
  GET(_req, _ctx) {
    return new Response(
      JSON.stringify({
        status: 'ok',
        runtime: 'deno',
        version: Deno.version.deno,
        timestamp: new Date().toISOString(),
      }),
      {
        status: 200,
        headers: { 'Content-Type': 'application/json' },
      }
    );
  },
};

With Oak Framework

import { Application, Router } from 'https://deno.land/x/oak/mod.ts';

const router = new Router();

router.get('/health', (ctx) => {
  ctx.response.body = {
    status: 'ok',
    runtime: 'deno',
    version: Deno.version.deno,
    uptime: performance.now() / 1000,
    timestamp: new Date().toISOString(),
  };
});

const app = new Application();
app.use(router.routes());
app.use(router.allowedMethods());

app.listen({ port: 8000 });

Heartbeat Monitoring for Deno Cron Jobs

Deno 2 has built-in cron support. Send heartbeats to Vigilmon after each run:

// cron.ts
const HEARTBEAT_URL = 'https://vigilmon.online/api/heartbeat/YOUR_MONITOR_ID';

Deno.cron('Daily cleanup', '0 2 * * *', async () => {
  console.log('Running daily cleanup...');

  // Your job logic
  await runCleanup();

  // Signal success to Vigilmon
  try {
    await fetch(HEARTBEAT_URL, { method: 'POST' });
    console.log('Heartbeat sent');
  } catch (err) {
    console.error('Failed to send heartbeat:', err);
  }
});

Deno Deploy Monitoring

For apps on Deno Deploy:

// Fresh app on Deno Deploy — routes/health.ts
import { Handlers } from '$fresh/server.ts';

export const handler: Handlers = {
  GET(_req) {
    return Response.json({
      status: 'ok',
      platform: 'deno-deploy',
      region: Deno.env.get('DENO_REGION') ?? 'unknown',
      timestamp: new Date().toISOString(),
    });
  },
};

Then monitor https://your-app.deno.dev/health in Vigilmon.

Running Deno in Production (systemd)

[Unit]
Description=Deno Application
After=network.target

[Service]
Type=simple
User=www-data
WorkingDirectory=/var/www/app
ExecStart=/usr/local/bin/deno run --allow-net --allow-env --allow-read server.ts
Restart=always
RestartSec=5
Environment=DENO_NO_UPDATE_CHECK=1

[Install]
WantedBy=multi-user.target

Setting Up Vigilmon

1. Sign up at vigilmon.online
2. Add monitor → paste your health endpoint URL
3. Configure alerts (email + Slack)
4. Add SSL monitor for your domain

Vigilmon checks from multiple global regions every 1-5 minutes.

Monitoring Checklist for Deno Apps

• [ ] /health endpoint returning 200 JSON
• [ ] KV or database connectivity check
• [ ] Heartbeat monitors for Deno.cron jobs
• [ ] Uptime monitor in Vigilmon
• [ ] SSL certificate monitor
• [ ] Process manager / systemd service
• [ ] Alert channels configured

Start monitoring your Deno app free →