Ntfy.sh

ntfy (pronounced notify) is a straightforward HTTP-based pub-sub notification service designed to send notifications to your phone or desktop. It allows you to send notifications through scripts from any computer or using a REST API. With its infinite flexibility and being 100% free software, ntfy is a powerful tool for developers and system administrators alike.

• Simple Integration: Publishing messages can be done via PUT or POST requests. Topics are created on the fly by subscribing or publishing to them.
• Receive Notifications: Subscribe to a topic and instantly receive notifications with different priorities, attachments, action buttons, tags, and emojis.
• Flexible Priorities: Define notification priorities that map to different sounds and vibration patterns.
• Action Buttons: React to notifications directly with customizable action buttons.
• Attachments: Send images, videos, and other files to your phone or computer instantly.
• Desktop Notifications: Use the web app to subscribe to topics and receive desktop notifications.
• Extensive Integrations: Easily integrate with various tools and services, including cronjobs, GitHub Actions, and home automation systems.

Whether you need to alert yourself about unauthorized logins, notify when a new episode of your TV show is available, or get updates from your home automation sensors, ntfy hooks into anything and everything. Its open-source nature and robust documentation make it a favorite among developers and power users.