When building your bot, there are a few character limits to consider.
A text message part can consist of up to 640 characters of text. Remember, the text should not be too dense – break it up into small chunks of a few sentences with a short delay in between. We recommend for long chunks of text to add a delay of 500ms per line of text.
Carousels can contain up to three kinds of text - the title, the subtitle and the button. The subtitle and button are optional. The title and subtitle have a limit of 80 characters each, whilst the button has a limit of 20 characters.
The persistent menu is made up of 3 buttons only, with each button having a limit of 20 characters.