Keron
Download
Get Keron
Free, and about two minutes to set up. The only thing Keron asks for afterwards is the Accessibility permission — without it macOS won't let any app see the notification banners it draws.
Setup
Installing Keron
-
Download and unzip
Grab the latest build using the button above and unzip it if your browser hasn't already.
-
Move it to Applications
Drag Keron.app into your
/Applicationsfolder. Keron needs to live in a stable location, because macOS ties the Accessibility permission to the app's path — moving it later means granting the permission again. It's also where Keron installs its own updates. -
Grant Accessibility
Keron asks for this on first launch. If you missed the prompt, open System Settings › Privacy & Security › Accessibility, then switch Keron on. There's no need to restart it — the engine starts the moment the permission lands, and the warning banner at the top of the window disappears on its own.
-
Send yourself a test banner
In the editor, hit Send Test Notification. You should see Keron's own banner appear wherever you've placed it. From here, drag the elements around until it looks the way you want.
Why Accessibility? macOS has no public API for restyling notification banners. Keron uses the Accessibility API to observe the system's Notification Center process, read each banner's app name, title, message and icon, and draw its own overlay in place of the original. There is no other way to do it, and it is the only permission Keron asks for. See exactly what it does with that access.
Something not working?
The support page covers the common cases — banners not being restyled, the wrong display, and Focus modes.