ntfy

A simple HTTP‑based publish‑subscribe service lets users push messages to phones or desktops via PUT or POST requests. Topics are created on demand, and any client can subscribe to receive notifications instantly, with optional priorities, icons, tags, emojis, action buttons, and file attachments such as images or videos. The service can be accessed through a public endpoint or self‑hosted, and client libraries are available for curl, CLI, JavaScript, Go, PowerShell, and Python.

Mobile delivery is provided by open‑source Android and iOS applications, which appear in the system notification area and support interaction through action buttons. A web interface also allows desktop notifications and manual topic management. Because the system is self‑hostable and released under the Apache‑2.0 license, users can run their own instance without sign‑up or subscription fees, while a hosted free tier is offered at ntfy.sh. The project targets developers and system administrators who need lightweight, scriptable push notifications for alerts, automation, or integration with other tools.