Description
Sentinel is a self-hosted monitoring platform for agencies and developers who look after other people's websites. It checks every website every minute (HTTP, HTTPS, DNS, SSL, response time, content and TCP ports), repeats a failing check before raising an alarm, and opens an incident with a full timeline only when the outage is real.
Where other monitors stop at "down", Sentinel keeps going. A small agent on your server reports the state of Nginx, Apache, OpenLiteSpeed, PHP-FPM, MySQL/MariaDB, Redis, Supervisor and Docker containers. Combined with recognition of WordPress, Laravel, PHP and Cloudflare error pages, the diagnostic engine names the real cause ("PHP-FPM is not running", "WordPress cannot connect to its database", "Container shop-web is exited") and runs the matching recovery action, verifies that the website is back, and tells you what happened. Attempt limits, cooldowns and a fixed allow-list keep automatic recovery safe.
Everything your clients see can carry your brand: a read-only portal, monthly reports as PDF, and public status pages with 90 days of uptime history.
Feature list
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- Checks every 1 to 60 minutes: HTTP/HTTPS status, response time, DNS, SSL validity and expiry, content match, TCP ports
- Confirmation retries before any alert, so flaky responses never page you
- Incidents with second-by-second timelines: detection, diagnosis, actions, verification, notifications
- Alerts via email, Telegram, Slack, Discord and HMAC-signed webhooks, with per-channel event subscriptions, test sends and a delivery log
- Outbound-only Linux server agent reporting CPU, memory, disk, load, systemd services and Docker containers
- Self-healing with signed, expiring commands: restart PHP-FPM, Nginx, Apache, OpenLiteSpeed, Redis, MySQL/MariaDB, Supervisor workers and Docker containers, clear the Laravel cache
- Diagnostic engine with root-cause rules, WordPress/Laravel/PHP/Cloudflare error-page recognition, healing policy with attempt limits, cooldown and verification
- Clients with a read-only portal, monthly reports (web, branded PDF, CSV)
- Public status pages per client and for the whole installation, 90-day uptime bars, announcements
- White-label: name, tagline, colour, logo, favicon (the Extended License also removes the vendor line); installable as an app on phones and desktops
- Team roles (administrator, member, client), two-factor authentication, personal API tokens and a REST API
- Web installer, health checks on the dashboard and from the command line, one-command upgrades, automatic data pruning
- Security headers, HTTPS and reverse-proxy support, rate limiting, encrypted secrets, license activation per domain
Requirements
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PHP 8.2+, MySQL 8 / MariaDB 10.6+, cron and a queue worker. Nginx or Apache. The server agent needs a Linux server with systemd and root access; websites hosted elsewhere are monitored without it.
What is in the download
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The complete application with production dependencies, the server agent, HTML documentation (installation, user guide, server agent, diagnostics, configuration, REST API) and a demo data seeder.
