Is there an API (like in Android TV) to overlay UI element on the screen?

Hi, I am looking for an API in webOS TV that allows a third-party app to render UI elements on the screen, and it should also work when I pick an HDMI source on my TV.

In Android TV, it is possible; here are a few references:

  1. In the following video, at 1:47, you can see that a third-party app can render the clock on the screen and even in HDMI source:
    AndroidTV - Aplikacja zegar na ekranie na stałe - OnScreenClock - YouTube

  2. Developer reference: Is it possible to draw overlay over any screen using 3rd party app in android TV? - Stack Overflow

Currently, no APIs for overlaying UI elements on the screen are provided. Sorry for not being helpful.

Hi, thanks for the answer.
I thought that maybe the toast API could help.
My use case is to show text on the screen, and it seems that this API can do it, right?
com.webos.notification | webOS Open Source Edition (

Can I use this API from my app, or is it limited to the system only?
Is it possible to update the text in the toast while it still displays? I can’t see anything about it in the docs, but maybe I am missing something.

We do not guarantee the compatibility of webOS TV apps with webOS OSE APIs. For webOS TV apps, please use webOS TV APIs only. Thank you.