Fly.io
Monitoring for scheduled jobs on Fly.io
Fly.io has no single “cron” product — teams schedule work with a supercronic process in a Machine, or with scheduled Fly Machines (fly machine run --schedule). Either way, nothing tells you when a scheduled run fails or a Machine does not wake up. A heartbeat makes those runs observable.
How scheduling looks on Fly.io
Two common patterns: run supercronic (a container-friendly cron) inside a long-lived Machine with a normal crontab, or use scheduled Fly Machines that boot on an hourly/daily cadence to run a one-shot command. Neither surfaces an alert when a job fails or a scheduled boot is missed.
With supercronic
Add the heartbeat ping to the crontab line so it fires only on success:
0 * * * * /app/bin/job && curl -fsS https://cronmint.com/ping/YOUR-TOKEN >/dev/nullWith a scheduled Fly Machine
For a Machine that boots on a schedule to run a one-shot command, ping at the end of that command:
sh -c 'node worker.js && curl -fsS https://cronmint.com/ping/YOUR-TOKEN >/dev/null'Catch a Machine that never wakes
Set the Cronmint interval to match the schedule. If a scheduled Machine fails to boot, or supercronic stops because the Machine was stopped, no ping arrives and Cronmint alerts you.
Monitor your Fly.io scheduled jobs
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Start freeFrequently asked questions
Does Fly.io have cron jobs?
Not as a dedicated product. You either run supercronic inside a Machine or use scheduled Fly Machines. Both run commands on a schedule but neither includes failure or missed-run alerting.
How do I monitor scheduled jobs on Fly.io?
Append a heartbeat ping to the scheduled command (supercronic crontab line or Machine command) so it fires only on success, and create a matching Cronmint monitor.
What if a scheduled Machine fails to start?
That is exactly what a heartbeat catches — no boot means no ping, and Cronmint flags the missed run.
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