It became a bit easier to extend kagi.el with your own FastGPT prompts. You could define the following prompt in your configuration:
(define-kagi-fast-prompt
my/synonym
"Give a synonym for the word: %s")
Now, my/synonym
becomes a real #emacs command that accepts text to fill in for the placeholder. You could use it from Lisp:
(my/synonym "happy")
Or use it interactively, where the word will be retrieved from the region or by reading the minibuffer.
Demo: https://asciinema.org/a/653482
The new kagi package is available in MELPA, or from Codeberg:
https://codeberg.org/bram85/kagi.el
#kagi