agg: keystroke overlay

[LangLangBart]

Feature Request

Ability to add an overlay of keystrokes to the gif.

Related tickets

• asciinema/asciinema #105

v2 format has a place for keypresses

Screenshots/ Gifs

• Image from tckmn/mkcast

• Gif with Gifox

[eduble]

Hi,

FYI, to solve this same problem I took a different approach and wrote a tool called demoterm able to show keypresses on a reserved zone at the bottom of the terminal.
You can combine it with asciinema for recording, i.e., asciinema rec -c demoterm.

I used it for instance for the terminal recordings of this blog post:
https://walt-project.liglab.fr/blog/2025-11-auto-completion

It works fine on my Ubuntu Linux system (i.e., in gnome-terminal). There might be issues if the terminal does not support some of the escape sequences needed (e.g., for saving and restoring cursor position and color modes) though.