Notifi is a FREE, minimal Push Notification app that sits in your Mac menu bar. When you open the app for the first time you are given a key that uniquely identifies you. Blurred in the image below:
With this key you can send HTTP requests (curl) to receive notifications on your mac.
First click on notifi which will appear on your menu bar at the top of your Mac. Here you can open your notifications and get your unique Credentials.
Send a notification with your desired programming language or through the terminal - See examples.
notifi is open source on GitHub.
icon from flaticon.com