David Adams

Posted on Feb 10

I Built a $9/mo Uptime Monitor in a Day — Here's What I Learned

#devops

I got tired of paying $50+/month for uptime monitoring on side projects that make $0. So I built my own.

The Problem

Every uptime monitoring service I tried was either:

Too expensive for indie projects (Pingdom, Datadog)
Too complex with features I don't need
Ugly dashboards that made me not want to use them

All I wanted was:

Check if my site is up
Tell me if it goes down
Don't charge me $50/month for it

The Build

I built OwlPulse in a single day using:

FastAPI for the backend (~500 lines)
SQLite for zero-config storage
APScheduler for background checks
Cloudflare Tunnel for deployment

The Core API

@app.post("/monitors")
async def create_monitor(monitor: MonitorCreate):
    api_key = secrets.token_urlsafe(32)
    # ... create monitor with API key
    return {"id": monitor_id, "api_key": api_key}

That's basically it. Create a monitor, get an API key, start checking.

Background Checking

async def check_monitor(monitor_id: int):
    async with httpx.AsyncClient() as client:
        start = time.time()
        response = await client.get(url, timeout=10)
        response_time = (time.time() - start) * 1000

        # Log the check, update status, fire webhook if changed

Pro plan gets 1-minute checks. Free gets 5-minute checks.

What I Learned

1. Simple beats feature-rich

I was tempted to add:

Multi-region checks
Fancy charts
Team management
SSL monitoring
etc.

But none of that matters if the core is solid. Ship simple, iterate later.

2. API-first is underrated

Most monitoring tools force you into their dashboard. I wanted something I could integrate anywhere — Slack bots, CLI tools, custom dashboards.

REST API with webhook callbacks = maximum flexibility.

3. Pricing is a feature

$9/mo unlimited monitors. That's it. No per-monitor pricing, no hidden fees, no enterprise upsells.

Indie devs shouldn't need to do math to figure out their monitoring bill.

Try It

OwlPulse is live at owlpulse.org.

Free tier: 3 monitors, 5-min checks
Pro: $9/mo unlimited, 1-min checks, webhooks

The whole thing is ~500 lines of Python. Sometimes the best solution is the boring one.

What's your uptime monitoring setup? Anyone else built their own?

DEV Community