SilenceWatch

SilenceWatch is a heartbeat monitor (a "dead man's switch") for cron jobs, scheduled tasks, backups and anything else that must run regularly. Each job sends a ping when it runs; if a ping doesn't arrive on time, an incident opens and you are alerted by email, Slack, Microsoft Teams, Discord or a signed webhook. The next ping resolves it.

A job that stops silently looks exactly like a job with nothing to do: no error, no log, nothing to see. SilenceWatch turns that absence into an alert.

How it works:

• Declare a check with an interval or a cron expression, a time zone and a grace period.
• Add one HTTP call at the end of the job (curl, or any HTTP client).
• Get alerted when the ping is late. Late checks are detected within seconds.

Spring Boot: nothing to declare by hand. Add the starter and an API key: on startup it discovers every @Scheduled method and Quartz job, declares each one with its resolved schedule, and reports every run with its duration and any exception. It never blocks or fails your job. A job removed from the code is marked orphaned, never deleted. Libraries for Python (Celery, django-celery-beat, APScheduler) and Laravel work the same way.

Works with crontab, systemd timers, Kubernetes CronJobs, GitHub Actions, Docker, Bash, PowerShell, Python, Node.js and Java.

Other features:

• Ping history, incidents and alerts, searchable
• REST API with project-scoped API keys
• Projects shared with your team
• Sign-in with passkeys, password, Google or Microsoft
• Interface in English and French, light and dark themes

Open source and self-hostable: Apache 2.0 license, one Docker image plus PostgreSQL (no Redis, no message broker). The self-hosted edition has no plan, no quota and no reserved feature.

Hosted version: free plan with 10 checks; Pro (€4.99/month, 100 checks) and Business (€19.99/month, 1,000 checks). Every plan has the same features, only the limits change.