Cron Job Heartbeat Monitor
Give each scheduled job a ping URL and get an email or Telegram alert when it fails or does not check in on time.
Economics
- Pricing example
- Free: 3 monitors. $5/month for 20 monitors, $12/month for 100
- Daily math
- $20/day is about $600/month, e.g. 60 users x $5 + 25 users x $12 = $600/month.
- Target if you hit the daily math
- Target: $600 / month at about 85 paying users
Audience and urgency
Audience: Indie developers, small SaaS teams and sysadmins running backups, cron scripts, queue workers and data syncs.
Urgency: Scheduled jobs fail silently. A backup or sync that stopped weeks ago is usually discovered only when someone needs the data.
MVP scope
- ✓ Create a monitor with an expected schedule (interval or cron expression) and grace period; get a unique ping URL
- ✓ Start, success and fail ping endpoints so run duration and exit status are recorded
- ✓ Alerts by email and Telegram bot (optional Slack webhook) for late or failed runs, plus a recovery notice
- ✓ Dashboard with the last 50 pings per monitor and a plain-English cron expression explainer
- ✓ Stripe subscription tiers that enforce monitor limits
Omitted features
- - Do NOT build website uptime checks in Day 1
- - Do NOT add SMS alerts (cost and abuse risk)
- - Do NOT build team roles or SSO
Suggested stack
- Frontend
- Next.js + Tailwind CSS
- Backend or API
- Postgres (Supabase or Neon) + a checker that runs every minute (Cloudflare Workers Cron Triggers or a small VPS)
- Payments
- Stripe Billing
- Hosting
- Cloudflare Workers + Pages, or Fly.io
Repository metadata
- Blueprint ID
cron-heartbeat-monitor- Category ID
dev_tools- Monetization ID
micro_subscription
Day-one distribution
Channels
- Reddit r/selfhosted and r/sysadmin (check self-promotion rules)
- Hacker News 'Show HN' with a plain technical write-up
- Copy-paste snippets for bash, Python, Node and GitHub Actions on a docs page
Reddit strategy
Share a free guide titled 'How to know when your cron job silently failed' with snippets; mention the free 3-monitor tier at the end.
Cold outreach or directory hook
List on developer-tool directories and alternative-to sites with an honest comparison page.
Search keywords
cron job monitoring, heartbeat monitoring for cron jobs, alert when cron job fails
One-shot master prompt
Build a "Cron Heartbeat Monitor" SaaS with Next.js, Tailwind CSS and Postgres.
Core requirements:
1. Monitor CRUD: name, schedule type (every N minutes/hours, or a cron expression with timezone), grace period, and alert channels. Show a plain-English explanation of the cron expression and the next 5 expected run times.
2. Public ping endpoints: GET/POST /p/{uuid} (success), /p/{uuid}/start and /p/{uuid}/fail. Store timestamp, source IP and optional body (max 10 KB) and compute run duration from start to success.
3. A checker that runs every minute marks monitors "late" after expected time + grace and "down" on fail pings, and sends one alert per state change by email (Resend) and Telegram bot, plus a recovery message.
4. Dashboard with status badges, last 50 pings, and copy-paste snippets (curl in crontab, Python, Node, GitHub Actions).
5. Stripe Billing tiers: Free 3 monitors, $5/month 20, $12/month 100; enforce limits on create.Comparable products
Published 2026-10-08.
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